Merge pull request #3934 from avagin:feature/fuse

PiperOrigin-RevId: 332122081

24 files changed, 3418 insertions, 298 deletions

diff --git a/test/fuse/BUILD b/test/fuse/BUILD
index 56157c96b..8e31fdd41 100644
--- a/test/fuse/BUILD
+++ b/test/fuse/BUILD
@@ -5,5 +5,69 @@ package(licenses = ["notice"])
 syscall_test(
     fuse = "True",
     test = "//test/fuse/linux:stat_test",
-    vfs2 = "True",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:open_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:release_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:mknod_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:symlink_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:readlink_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:mkdir_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:read_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:write_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:rmdir_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:readdir_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:create_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:unlink_test",
+)
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:setstat_test",
 )
diff --git a/test/fuse/README.md b/test/fuse/README.md
index 734c3a4e3..65add57e2 100644
--- a/test/fuse/README.md
+++ b/test/fuse/README.md
@@ -1,65 +1,114 @@
 # gVisor FUSE Test Suite
 
-This is an integration test suite for fuse(4) filesystem. It runs under both
-gVisor and Linux, and ensures compatibility between the two. This test suite is
-based on system calls test.
+This is an integration test suite for fuse(4) filesystem. It runs under gVisor
+sandbox container with VFS2 and FUSE function enabled.
 
-This document describes the framework of fuse integration test and the
-guidelines that should be followed when adding new fuse tests.
+This document describes the framework of FUSE integration test, how to use it,
+and the guidelines that should be followed when adding new testing features.
 
 ## Integration Test Framework
 
-Please refer to the figure below. `>` is entering the function, `<` is leaving
-the function, and `=` indicates sequentially entering and leaving.
+By inheriting the `FuseTest` class defined in `linux/fuse_base.h`, every test
+fixture can run in an environment with `mount_point_` mounted by a fake FUSE
+server. It creates a `socketpair(2)` to send and receive control commands and
+data between the client and the server. Because the FUSE server runs in the
+background thread, gTest cannot catch its assertion failure immediately. Thus,
+`TearDown()` function sends command to the FUSE server to check if all gTest
+assertion in the server are successful and all requests and preset responses are
+consumed.
+
+## Communication Diagram
+
+Diagram below describes how a testing thread communicates with the FUSE server
+to achieve integration test.
+
+For the following diagram, `>` means entering the function, `<` is leaving the
+function, and `=` indicates sequentially entering and leaving. Not necessarily
+follow exactly the below diagram due to the nature of a multi-threaded system,
+however, it is still helpful to know when the client waits for the server to
+complete a command and when the server awaits the next instruction.
 
 ```
- |  Client (Test Main Process)         |  Server (FUSE Daemon)
- |                                     |
- |  >TEST_F()                          |
- |    >SetUp()                         |
- |      =MountFuse()                   |
- |      >SetUpFuseServer()             |
- |        [create communication pipes] |
- |        =fork()                      |        =fork()
- |        >WaitCompleted()             |
- |          [wait for MarkDone()]      |
- |                                     |        =ConsumeFuseInit()
- |                                     |        =MarkDone()
- |        <WaitCompleted()             |
- |      <SetUpFuseServer()             |
- |    <SetUp()                         |
- |    >SetExpected()                   |
- |      [construct expected reaction]  |
- |                                     |        >FuseLoop()
- |                                     |          >ReceiveExpected()
- |                                     |            [wait data from pipe]
- |      [write data to pipe]           |
- |      [wait for MarkDone()]          |
- |                                     |            [save data to memory]
- |                                     |            =MarkDone()
- |    <SetExpected()                   |
- |                                     |          <ReceiveExpected()
- |                                     |          >read()
- |                                     |            [wait for fs operation]
- |    >[Do fs operation]               |
- |      [wait for fs response]         |
- |                                     |          <read()
- |                                     |          =CompareRequest()
- |                                     |          =write() [write fs response]
- |    <[Do fs operation]               |
- |    =[Test fs operation result]      |
- |    =[wait for MarkDone()]           |
- |                                     |          =MarkDone()
- |    >TearDown()                      |
- |      =UnmountFuse()                 |
- |    <TearDown()                      |
- |  <TEST_F()                          |
+|  Client (Testing Thread)            |  Server (FUSE Server Thread)
+|                                     |
+|  >TEST_F()                          |
+|    >SetUp()                         |
+|      =MountFuse()                   |
+|      >SetUpFuseServer()             |
+|        [create communication socket]|
+|        =fork()                      |      =fork()
+|        [wait server complete]       |
+|                                     |      =ServerConsumeFuseInit()
+|                                     |      =ServerCompleteWith()
+|      <SetUpFuseServer()             |
+|    <SetUp()                         |
+|    [testing main]                   |
+|                                     |      >ServerFuseLoop()
+|                                     |        [poll on socket and fd]
+|    >SetServerResponse()             |
+|      [write data to socket]         |
+|      [wait server complete]         |
+|                                     |        [socket event occurs]
+|                                     |        >ServerHandleCommand()
+|                                     |          >ServerReceiveResponse()
+|                                     |            [read data from socket]
+|                                     |            [save data to memory]
+|                                     |          <ServerReceiveResponse()
+|                                     |          =ServerCompleteWith()
+|    <SetServerResponse()             |
+|                                     |        <ServerHandleCommand()
+|    >[Do fs operation]               |
+|      [wait for fs response]         |
+|                                     |        [fd event occurs]
+|                                     |        >ServerProcessFuseRequest()
+|                                     |          =[read fs request]
+|                                     |          =[save fs request to memory]
+|                                     |          =[write fs response]
+|    <[Do fs operation]               |
+|                                     |        <ServerProcessFuseRequest()
+|                                     |
+|    =[Test fs operation result]      |
+|                                     |
+|    >GetServerActualRequest()        |
+|      [write data to socket]         |
+|      [wait data from server]        |
+|                                     |        [socket event occurs]
+|                                     |        >ServerHandleCommand()
+|                                     |          >ServerSendReceivedRequest()
+|                                     |            [write data to socket]
+|      [read data from socket]        |
+|      [wait server complete]         |
+|                                     |          <ServerSendReceivedRequest()
+|                                     |          =ServerCompleteWith()
+|    <GetServerActualRequest()        |
+|                                     |        <ServerHandleCommand()
+|                                     |
+|    =[Test actual request]           |
+|                                     |
+|    >TearDown()                      |
+|      ...                            |
+|      >GetServerNumUnsentResponses() |
+|        [write data to socket]       |
+|        [wait server complete]       |
+|                                     |        [socket event arrive]
+|                                     |        >ServerHandleCommand()
+|                                     |          >ServerSendData()
+|                                     |            [write data to socket]
+|                                     |          <ServerSendData()
+|                                     |          =ServerCompleteWith()
+|        [read data from socket]      |
+|        [test if all succeeded]      |
+|      <GetServerNumUnsentResponses() |
+|                                     |        <ServerHandleCommand()
+|      =UnmountFuse()                 |
+|    <TearDown()                      |
+|  <TEST_F()                          |
 ```
 
 ## Running the tests
 
-Based on syscall tests, fuse tests can run in different environments. To enable
-fuse testing environment, the test targets should be appended with `_fuse`.
+Based on syscall tests, FUSE tests generate targets only with vfs2 and fuse
+enabled. The corresponding targets end in `_fuse`.
 
 For example, to run fuse test in `stat_test.cc`:
 
@@ -77,17 +126,16 @@ $ bazel test --test_tag_filters=fuse //test/fuse/...
 
 1.  Add test targets in `BUILD` and `linux/BUILD`.
 2.  Inherit your test from `FuseTest` base class. It allows you to:
-    -   Run a fake FUSE server in background during each test setup.
-    -   Create pipes for communication and provide utility functions.
-    -   Stop FUSE server after test completes.
-3.  Customize your comparison function for request assessment in FUSE server.
-4.  Add the mapping of the size of structs if you are working on new FUSE
-    opcode.
-    -   Please update `FuseTest::GetPayloadSize()` for each new FUSE opcode.
-5.  Build the expected request-response pair of your FUSE operation.
-6.  Call `SetExpected()` function to inject the expected reaction.
-7.  Check the response and/or errors.
-8.  Finally call `WaitCompleted()` to ensure the FUSE server acts correctly.
+    -   Fork a fake FUSE server in background during each test setup.
+    -   Create a pair of sockets for communication and provide utility
+        functions.
+    -   Stop FUSE server and check if error occurs in it after test completes.
+3.  Build the expected opcode-response pairs of your FUSE operation.
+4.  Call `SetServerResponse()` to preset the next expected opcode and response.
+5.  Do real filesystem operations (FUSE is mounted at `mount_point_`).
+6.  Check FUSE response and/or errors.
+7.  Retrieve FUSE request by `GetServerActualRequest()`.
+8.  Check if the request is as expected.
 
 A few customized matchers used in syscalls test are encouraged to test the
 outcome of filesystem operations. Such as:
@@ -101,3 +149,40 @@ SyscallFailsWithErrno(...)
 
 Please refer to [test/syscalls/README.md](../syscalls/README.md) for further
 details.
+
+## Writing a new FuseTestCmd
+
+A `FuseTestCmd` is a control protocol used in the communication between the
+testing thread and the FUSE server. Such commands are sent from the testing
+thread to the FUSE server to set up, control, or inspect the behavior of the
+FUSE server in response to a sequence of FUSE requests.
+
+The lifecycle of a command contains following steps:
+
+1.  The testing thread sends a `FuseTestCmd` via socket and waits for
+    completion.
+2.  The FUSE server receives the command and does corresponding action.
+3.  (Optional) The testing thread reads data from socket.
+4.  The FUSE server sends a success indicator via socket after processing.
+5.  The testing thread gets the success signal and continues testing.
+
+The success indicator, i.e. `WaitServerComplete()`, is crucial at the end of
+each `FuseTestCmd` sent from the testing thread. Because we don't want to begin
+filesystem operation if the requests have not been completely set up. Also, to
+test FUSE interactions in a sequential manner, concurrent requests are not
+supported now.
+
+To add a new `FuseTestCmd`, one must comply with following format:
+
+1.  Add a new `FuseTestCmd` enum class item defined in `linux/fuse_base.h`
+2.  Add a `SetServerXXX()` or `GetServerXXX()` public function in `FuseTest`.
+    This is how the testing thread will call to send control message. Define how
+    many bytes you want to send along with the command and what you will expect
+    to receive. Finally it should block and wait for a success indicator from
+    the FUSE server.
+3.  Add a handler logic in the switch condition of `ServerHandleCommand()`. Use
+    `ServerSendData()` or declare a new private function such as
+    `ServerReceiveXXX()` or `ServerSendXXX()`. It is mandatory to set it private
+    since only the FUSE server (forked from `FuseTest` base class) can call it.
+    This is the server part of the specific `FuseTestCmd` and the format of the
+    data should be consistent with what the client expects in the previous step.
diff --git a/test/fuse/linux/BUILD b/test/fuse/linux/BUILD
index 4871bb531..7673252ec 100644
--- a/test/fuse/linux/BUILD
+++ b/test/fuse/linux/BUILD
@@ -11,7 +11,134 @@ cc_binary(
     srcs = ["stat_test.cc"],
     deps = [
         gtest,
+        ":fuse_fd_util",
+        "//test/util:cleanup",
+        "//test/util:fs_util",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "open_test",
+    testonly = 1,
+    srcs = ["open_test.cc"],
+    deps = [
+        gtest,
         ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "release_test",
+    testonly = 1,
+    srcs = ["release_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "mknod_test",
+    testonly = 1,
+    srcs = ["mknod_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "symlink_test",
+    testonly = 1,
+    srcs = ["symlink_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "readlink_test",
+    testonly = 1,
+    srcs = ["readlink_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "mkdir_test",
+    testonly = 1,
+    srcs = ["mkdir_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "setstat_test",
+    testonly = 1,
+    srcs = ["setstat_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_fd_util",
+        "//test/util:cleanup",
+        "//test/util:fs_util",
+        "//test/util:fuse_util",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "rmdir_test",
+    testonly = 1,
+    srcs = ["rmdir_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fs_util",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "readdir_test",
+    testonly = 1,
+    srcs = ["readdir_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fs_util",
+        "//test/util:fuse_util",
         "//test/util:test_main",
         "//test/util:test_util",
     ],
@@ -24,9 +151,80 @@ cc_library(
     hdrs = ["fuse_base.h"],
     deps = [
         gtest,
+        "//test/util:fuse_util",
         "//test/util:posix_error",
         "//test/util:temp_path",
         "//test/util:test_util",
         "@com_google_absl//absl/strings:str_format",
     ],
 )
+
+cc_library(
+    name = "fuse_fd_util",
+    testonly = 1,
+    srcs = ["fuse_fd_util.cc"],
+    hdrs = ["fuse_fd_util.h"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:cleanup",
+        "//test/util:file_descriptor",
+        "//test/util:fuse_util",
+        "//test/util:posix_error",
+    ],
+)
+
+cc_binary(
+    name = "read_test",
+    testonly = 1,
+    srcs = ["read_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "write_test",
+    testonly = 1,
+    srcs = ["write_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "create_test",
+    testonly = 1,
+    srcs = ["create_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fs_util",
+        "//test/util:fuse_util",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
+cc_binary(
+    name = "unlink_test",
+    testonly = 1,
+    srcs = ["unlink_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:temp_umask",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
diff --git a/test/fuse/linux/create_test.cc b/test/fuse/linux/create_test.cc
new file mode 100644
index 000000000..9a0219a58
--- /dev/null
+++ b/test/fuse/linux/create_test.cc
@@ -0,0 +1,128 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fs_util.h"
+#include "test/util/fuse_util.h"
+#include "test/util/temp_umask.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class CreateTest : public FuseTest {
+ protected:
+  const std::string test_file_name_ = "test_file";
+  const mode_t mode = S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(CreateTest, CreateFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_name_);
+
+  // Ensure the file doesn't exist.
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header),
+      .error = -ENOENT,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header);
+  SetServerResponse(FUSE_LOOKUP, iov_out);
+
+  // creat(2) is equal to open(2) with open_flags O_CREAT | O_WRONLY | O_TRUNC.
+  const mode_t new_mask = S_IWGRP | S_IWOTH;
+  const int open_flags = O_CREAT | O_WRONLY | O_TRUNC;
+  out_header.error = 0;
+  out_header.len = sizeof(struct fuse_out_header) +
+                   sizeof(struct fuse_entry_out) + sizeof(struct fuse_open_out);
+  struct fuse_entry_out entry_payload = DefaultEntryOut(mode & ~new_mask, 2);
+  struct fuse_open_out out_payload = {
+      .fh = 1,
+      .open_flags = open_flags,
+  };
+  iov_out = FuseGenerateIovecs(out_header, entry_payload, out_payload);
+  SetServerResponse(FUSE_CREATE, iov_out);
+
+  // kernfs generates a successive FUSE_OPEN after the file is created. Linux's
+  // fuse kernel module will not send this FUSE_OPEN after creat(2).
+  out_header.len =
+      sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out);
+  iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_OPEN, iov_out);
+
+  int fd;
+  TempUmask mask(new_mask);
+  EXPECT_THAT(fd = creat(test_file_path.c_str(), mode), SyscallSucceeds());
+  EXPECT_THAT(fcntl(fd, F_GETFL),
+              SyscallSucceedsWithValue(open_flags & O_ACCMODE));
+
+  struct fuse_in_header in_header;
+  struct fuse_create_in in_payload;
+  std::vector<char> name(test_file_name_.size() + 1);
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload, name);
+
+  // Skip the request of FUSE_LOOKUP.
+  SkipServerActualRequest();
+
+  // Get the first FUSE_CREATE.
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload) +
+                               test_file_name_.size() + 1);
+  EXPECT_EQ(in_header.opcode, FUSE_CREATE);
+  EXPECT_EQ(in_payload.flags, open_flags);
+  EXPECT_EQ(in_payload.mode, mode & ~new_mask);
+  EXPECT_EQ(in_payload.umask, new_mask);
+  EXPECT_EQ(std::string(name.data()), test_file_name_);
+
+  // Get the successive FUSE_OPEN.
+  struct fuse_open_in in_payload_open;
+  iov_in = FuseGenerateIovecs(in_header, in_payload_open);
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload_open));
+  EXPECT_EQ(in_header.opcode, FUSE_OPEN);
+  EXPECT_EQ(in_payload_open.flags, open_flags & O_ACCMODE);
+
+  EXPECT_THAT(close(fd), SyscallSucceeds());
+  // Skip the FUSE_RELEASE.
+  SkipServerActualRequest();
+}
+
+TEST_F(CreateTest, CreateFileAlreadyExists) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_name_);
+
+  const int open_flags = O_CREAT | O_EXCL;
+
+  SetServerInodeLookup(test_file_name_);
+
+  EXPECT_THAT(open(test_file_path.c_str(), mode, open_flags),
+              SyscallFailsWithErrno(EEXIST));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/fuse_base.cc b/test/fuse/linux/fuse_base.cc
index 9c3124472..5b45804e1 100644
--- a/test/fuse/linux/fuse_base.cc
+++ b/test/fuse/linux/fuse_base.cc
@@ -16,17 +16,17 @@
 
 #include <fcntl.h>
 #include <linux/fuse.h>
-#include <string.h>
+#include <poll.h>
 #include <sys/mount.h>
+#include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <unistd.h>
 
-#include <iostream>
-
 #include "gtest/gtest.h"
 #include "absl/strings/str_format.h"
+#include "test/util/fuse_util.h"
 #include "test/util/posix_error.h"
 #include "test/util/temp_path.h"
 #include "test/util/test_util.h"
@@ -39,49 +39,123 @@ void FuseTest::SetUp() {
   SetUpFuseServer();
 }
 
-void FuseTest::TearDown() { UnmountFuse(); }
-
-// Since CompareRequest is running in background thread, gTest assertions and
-// expectations won't directly reflect the test result. However, the FUSE
-// background server still connects to the same standard I/O as testing main
-// thread. So EXPECT_XX can still be used to show different results. To
-// ensure failed testing result is observable, return false and the result
-// will be sent to test main thread via pipe.
-bool FuseTest::CompareRequest(void* expected_mem, size_t expected_len,
-                              void* real_mem, size_t real_len) {
-  if (expected_len != real_len) return false;
-  return memcmp(expected_mem, real_mem, expected_len) == 0;
+void FuseTest::TearDown() {
+  EXPECT_EQ(GetServerNumUnconsumedRequests(), 0);
+  EXPECT_EQ(GetServerNumUnsentResponses(), 0);
+  UnmountFuse();
 }
 
-// SetExpected is called by the testing main thread to set expected request-
-// response pair of a single FUSE operation.
-void FuseTest::SetExpected(struct iovec* iov_in, int iov_in_cnt,
-                           struct iovec* iov_out, int iov_out_cnt) {
-  EXPECT_THAT(RetryEINTR(writev)(set_expected_[1], iov_in, iov_in_cnt),
-              SyscallSucceedsWithValue(::testing::Gt(0)));
-  WaitCompleted();
+// Sends 3 parts of data to the FUSE server:
+//   1. The `kSetResponse` command
+//   2. The expected opcode
+//   3. The fake FUSE response
+// Then waits for the FUSE server to notify its completion.
+void FuseTest::SetServerResponse(uint32_t opcode,
+                                 std::vector<struct iovec>& iovecs) {
+  uint32_t cmd = static_cast<uint32_t>(FuseTestCmd::kSetResponse);
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &opcode, sizeof(opcode)),
+              SyscallSucceedsWithValue(sizeof(opcode)));
 
-  EXPECT_THAT(RetryEINTR(writev)(set_expected_[1], iov_out, iov_out_cnt),
-              SyscallSucceedsWithValue(::testing::Gt(0)));
-  WaitCompleted();
+  EXPECT_THAT(RetryEINTR(writev)(sock_[0], iovecs.data(), iovecs.size()),
+              SyscallSucceeds());
+
+  WaitServerComplete();
 }
 
-// WaitCompleted waits for the FUSE server to finish its job and check if it
+// Waits for the FUSE server to finish its blocking job and check if it
 // completes without errors.
-void FuseTest::WaitCompleted() {
-  char success;
-  EXPECT_THAT(RetryEINTR(read)(done_[0], &success, sizeof(success)),
-              SyscallSucceedsWithValue(1));
+void FuseTest::WaitServerComplete() {
+  uint32_t success;
+  EXPECT_THAT(RetryEINTR(read)(sock_[0], &success, sizeof(success)),
+              SyscallSucceedsWithValue(sizeof(success)));
+  ASSERT_EQ(success, 1);
+}
+
+// Sends the `kGetRequest` command to the FUSE server, then reads the next
+// request into iovec struct. The order of calling this function should be
+// the same as the one of SetServerResponse().
+void FuseTest::GetServerActualRequest(std::vector<struct iovec>& iovecs) {
+  uint32_t cmd = static_cast<uint32_t>(FuseTestCmd::kGetRequest);
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  EXPECT_THAT(RetryEINTR(readv)(sock_[0], iovecs.data(), iovecs.size()),
+              SyscallSucceeds());
+
+  WaitServerComplete();
+}
+
+// Sends a FuseTestCmd command to the FUSE server, reads from the socket, and
+// returns the corresponding data.
+uint32_t FuseTest::GetServerData(uint32_t cmd) {
+  uint32_t data;
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  EXPECT_THAT(RetryEINTR(read)(sock_[0], &data, sizeof(data)),
+              SyscallSucceedsWithValue(sizeof(data)));
+
+  WaitServerComplete();
+  return data;
+}
+
+uint32_t FuseTest::GetServerNumUnconsumedRequests() {
+  return GetServerData(
+      static_cast<uint32_t>(FuseTestCmd::kGetNumUnconsumedRequests));
+}
+
+uint32_t FuseTest::GetServerNumUnsentResponses() {
+  return GetServerData(
+      static_cast<uint32_t>(FuseTestCmd::kGetNumUnsentResponses));
+}
+
+uint32_t FuseTest::GetServerTotalReceivedBytes() {
+  return GetServerData(
+      static_cast<uint32_t>(FuseTestCmd::kGetTotalReceivedBytes));
+}
+
+// Sends the `kSkipRequest` command to the FUSE server, which would skip
+// current stored request data.
+void FuseTest::SkipServerActualRequest() {
+  uint32_t cmd = static_cast<uint32_t>(FuseTestCmd::kSkipRequest);
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  WaitServerComplete();
 }
 
-void FuseTest::MountFuse() {
+// Sends the `kSetInodeLookup` command, expected mode, and the path of the
+// inode to create under the mount point.
+void FuseTest::SetServerInodeLookup(const std::string& path, mode_t mode,
+                                    uint64_t size) {
+  uint32_t cmd = static_cast<uint32_t>(FuseTestCmd::kSetInodeLookup);
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &mode, sizeof(mode)),
+              SyscallSucceedsWithValue(sizeof(mode)));
+
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &size, sizeof(size)),
+              SyscallSucceedsWithValue(sizeof(size)));
+
+  // Pad 1 byte for null-terminate c-string.
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], path.c_str(), path.size() + 1),
+              SyscallSucceedsWithValue(path.size() + 1));
+
+  WaitServerComplete();
+}
+
+void FuseTest::MountFuse(const char* mountOpts) {
   EXPECT_THAT(dev_fd_ = open("/dev/fuse", O_RDWR), SyscallSucceeds());
 
-  std::string mount_opts = absl::StrFormat("fd=%d,%s", dev_fd_, kMountOpts);
+  std::string mount_opts = absl::StrFormat("fd=%d,%s", dev_fd_, mountOpts);
   mount_point_ = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
   EXPECT_THAT(mount("fuse", mount_point_.path().c_str(), "fuse",
                     MS_NODEV | MS_NOSUID, mount_opts.c_str()),
-              SyscallSucceedsWithValue(0));
+              SyscallSucceeds());
 }
 
 void FuseTest::UnmountFuse() {
@@ -89,13 +163,13 @@ void FuseTest::UnmountFuse() {
   // TODO(gvisor.dev/issue/3330): ensure the process is terminated successfully.
 }
 
-// ConsumeFuseInit consumes the first FUSE request and returns the
-// corresponding PosixError.
-PosixError FuseTest::ConsumeFuseInit() {
+// Consumes the first FUSE request and returns the corresponding PosixError.
+PosixError FuseTest::ServerConsumeFuseInit(
+    const struct fuse_init_out* out_payload) {
+  std::vector<char> buf(FUSE_MIN_READ_BUFFER);
   RETURN_ERROR_IF_SYSCALL_FAIL(
-      RetryEINTR(read)(dev_fd_, buf_.data(), buf_.size()));
+      RetryEINTR(read)(dev_fd_, buf.data(), buf.size()));
 
-  struct iovec iov_out[2];
   struct fuse_out_header out_header = {
       .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_init_out),
       .error = 0,
@@ -103,72 +177,74 @@ PosixError FuseTest::ConsumeFuseInit() {
   };
   // Returns a fake fuse_init_out with 7.0 version to avoid ECONNREFUSED
   // error in the initialization of FUSE connection.
-  struct fuse_init_out out_payload = {
-      .major = 7,
-  };
-  iov_out[0].iov_len = sizeof(out_header);
-  iov_out[0].iov_base = &out_header;
-  iov_out[1].iov_len = sizeof(out_payload);
-  iov_out[1].iov_base = &out_payload;
+  auto iov_out = FuseGenerateIovecs(
+      out_header, *const_cast<struct fuse_init_out*>(out_payload));
 
-  RETURN_ERROR_IF_SYSCALL_FAIL(RetryEINTR(writev)(dev_fd_, iov_out, 2));
+  RETURN_ERROR_IF_SYSCALL_FAIL(
+      RetryEINTR(writev)(dev_fd_, iov_out.data(), iov_out.size()));
   return NoError();
 }
 
-// ReceiveExpected reads 1 pair of expected fuse request-response `iovec`s
-// from pipe and save them into member variables of this testing instance.
-void FuseTest::ReceiveExpected() {
-  // Set expected fuse_in request.
-  EXPECT_THAT(len_in_ = RetryEINTR(read)(set_expected_[0], mem_in_.data(),
-                                         mem_in_.size()),
-              SyscallSucceedsWithValue(::testing::Gt(0)));
-  MarkDone(len_in_ > 0);
+// Reads 1 expected opcode and a fake response from socket and save them into
+// the serial buffer of this testing instance.
+void FuseTest::ServerReceiveResponse() {
+  ssize_t len;
+  uint32_t opcode;
+  std::vector<char> buf(FUSE_MIN_READ_BUFFER);
+  EXPECT_THAT(RetryEINTR(read)(sock_[1], &opcode, sizeof(opcode)),
+              SyscallSucceedsWithValue(sizeof(opcode)));
 
-  // Set expected fuse_out response.
-  EXPECT_THAT(len_out_ = RetryEINTR(read)(set_expected_[0], mem_out_.data(),
-                                          mem_out_.size()),
-              SyscallSucceedsWithValue(::testing::Gt(0)));
-  MarkDone(len_out_ > 0);
+  EXPECT_THAT(len = RetryEINTR(read)(sock_[1], buf.data(), buf.size()),
+              SyscallSucceeds());
+
+  responses_.AddMemBlock(opcode, buf.data(), len);
 }
 
-// MarkDone writes 1 byte of success indicator through pipe.
-void FuseTest::MarkDone(bool success) {
-  char data = success ? 1 : 0;
-  EXPECT_THAT(RetryEINTR(write)(done_[1], &data, sizeof(data)),
-              SyscallSucceedsWithValue(1));
+// Writes 1 byte of success indicator through socket.
+void FuseTest::ServerCompleteWith(bool success) {
+  uint32_t data = success ? 1 : 0;
+  ServerSendData(data);
 }
 
-// FuseLoop is the implementation of the fake FUSE server. Read from /dev/fuse,
-// compare the request by CompareRequest (use derived function if specified),
-// and write the expected response to /dev/fuse.
-void FuseTest::FuseLoop() {
-  bool success = true;
-  ssize_t len = 0;
+// ServerFuseLoop is the implementation of the fake FUSE server. Monitors 2
+// file descriptors: /dev/fuse and sock_[1]. Events from /dev/fuse are FUSE
+// requests and events from sock_[1] are FUSE testing commands, leading by
+// a FuseTestCmd data to indicate the command.
+void FuseTest::ServerFuseLoop() {
+  const int nfds = 2;
+  struct pollfd fds[nfds] = {
+      {
+          .fd = dev_fd_,
+          .events = POLL_IN | POLLHUP | POLLERR | POLLNVAL,
+      },
+      {
+          .fd = sock_[1],
+          .events = POLL_IN | POLLHUP | POLLERR | POLLNVAL,
+      },
+  };
+
   while (true) {
-    ReceiveExpected();
+    ASSERT_THAT(poll(fds, nfds, -1), SyscallSucceeds());
 
-    EXPECT_THAT(len = RetryEINTR(read)(dev_fd_, buf_.data(), buf_.size()),
-                SyscallSucceedsWithValue(len_in_));
-    if (len != len_in_) success = false;
+    for (int fd_idx = 0; fd_idx < nfds; ++fd_idx) {
+      if (fds[fd_idx].revents == 0) continue;
 
-    if (!CompareRequest(buf_.data(), len_in_, mem_in_.data(), len_in_)) {
-      std::cerr << "the FUSE request is not expected" << std::endl;
-      success = false;
+      ASSERT_EQ(fds[fd_idx].revents, POLL_IN);
+      if (fds[fd_idx].fd == sock_[1]) {
+        ServerHandleCommand();
+      } else if (fds[fd_idx].fd == dev_fd_) {
+        ServerProcessFuseRequest();
+      }
     }
-
-    EXPECT_THAT(len = RetryEINTR(write)(dev_fd_, mem_out_.data(), len_out_),
-                SyscallSucceedsWithValue(len_out_));
-    if (len != len_out_) success = false;
-    MarkDone(success);
   }
 }
 
-// SetUpFuseServer creates 2 pipes. First is for testing client to send the
-// expected request-response pair, and the other acts as a checkpoint for the
-// FUSE server to notify the client that it can proceed.
-void FuseTest::SetUpFuseServer() {
-  ASSERT_THAT(pipe(set_expected_), SyscallSucceedsWithValue(0));
-  ASSERT_THAT(pipe(done_), SyscallSucceedsWithValue(0));
+// SetUpFuseServer creates 1 socketpair and fork the process. The parent thread
+// becomes testing thread and the child thread becomes the FUSE server running
+// in background. These 2 threads are connected via socketpair. sock_[0] is
+// opened in testing thread and sock_[1] is opened in the FUSE server.
+void FuseTest::SetUpFuseServer(const struct fuse_init_out* payload) {
+  ASSERT_THAT(socketpair(AF_UNIX, SOCK_STREAM, 0, sock_), SyscallSucceeds());
 
   switch (fork()) {
     case -1:
@@ -177,31 +253,194 @@ void FuseTest::SetUpFuseServer() {
     case 0:
       break;
     default:
-      ASSERT_THAT(close(set_expected_[0]), SyscallSucceedsWithValue(0));
-      ASSERT_THAT(close(done_[1]), SyscallSucceedsWithValue(0));
-      WaitCompleted();
+      ASSERT_THAT(close(sock_[1]), SyscallSucceeds());
+      WaitServerComplete();
       return;
   }
 
-  ASSERT_THAT(close(set_expected_[1]), SyscallSucceedsWithValue(0));
-  ASSERT_THAT(close(done_[0]), SyscallSucceedsWithValue(0));
-
-  MarkDone(ConsumeFuseInit().ok());
-
-  FuseLoop();
+  // Begin child thread, i.e. the FUSE server.
+  ASSERT_THAT(close(sock_[0]), SyscallSucceeds());
+  ServerCompleteWith(ServerConsumeFuseInit(payload).ok());
+  ServerFuseLoop();
   _exit(0);
 }
 
-// GetPayloadSize is a helper function to get the number of bytes of a
-// specific FUSE operation struct.
-size_t FuseTest::GetPayloadSize(uint32_t opcode, bool in) {
-  switch (opcode) {
-    case FUSE_INIT:
-      return in ? sizeof(struct fuse_init_in) : sizeof(struct fuse_init_out);
+void FuseTest::ServerSendData(uint32_t data) {
+  EXPECT_THAT(RetryEINTR(write)(sock_[1], &data, sizeof(data)),
+              SyscallSucceedsWithValue(sizeof(data)));
+}
+
+// Reads FuseTestCmd sent from testing thread and routes to correct handler.
+// Since each command should be a blocking operation, a `ServerCompleteWith()`
+// is required after the switch keyword.
+void FuseTest::ServerHandleCommand() {
+  uint32_t cmd;
+  EXPECT_THAT(RetryEINTR(read)(sock_[1], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  switch (static_cast<FuseTestCmd>(cmd)) {
+    case FuseTestCmd::kSetResponse:
+      ServerReceiveResponse();
+      break;
+    case FuseTestCmd::kSetInodeLookup:
+      ServerReceiveInodeLookup();
+      break;
+    case FuseTestCmd::kGetRequest:
+      ServerSendReceivedRequest();
+      break;
+    case FuseTestCmd::kGetTotalReceivedBytes:
+      ServerSendData(static_cast<uint32_t>(requests_.UsedBytes()));
+      break;
+    case FuseTestCmd::kGetNumUnconsumedRequests:
+      ServerSendData(static_cast<uint32_t>(requests_.RemainingBlocks()));
+      break;
+    case FuseTestCmd::kGetNumUnsentResponses:
+      ServerSendData(static_cast<uint32_t>(responses_.RemainingBlocks()));
+      break;
+    case FuseTestCmd::kSkipRequest:
+      ServerSkipReceivedRequest();
+      break;
     default:
+      FAIL() << "Unknown FuseTestCmd " << cmd;
       break;
   }
-  return 0;
+
+  ServerCompleteWith(!HasFailure());
+}
+
+// Reads the expected file mode and the path of one file. Crafts a basic
+// `fuse_entry_out` memory block and inserts into a map for future use.
+// The FUSE server will always return this response if a FUSE_LOOKUP
+// request with this specific path comes in.
+void FuseTest::ServerReceiveInodeLookup() {
+  mode_t mode;
+  uint64_t size;
+  std::vector<char> buf(FUSE_MIN_READ_BUFFER);
+
+  EXPECT_THAT(RetryEINTR(read)(sock_[1], &mode, sizeof(mode)),
+              SyscallSucceedsWithValue(sizeof(mode)));
+
+  EXPECT_THAT(RetryEINTR(read)(sock_[1], &size, sizeof(size)),
+              SyscallSucceedsWithValue(sizeof(size)));
+
+  EXPECT_THAT(RetryEINTR(read)(sock_[1], buf.data(), buf.size()),
+              SyscallSucceeds());
+
+  std::string path(buf.data());
+
+  uint32_t out_len =
+      sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out);
+  struct fuse_out_header out_header = {
+      .len = out_len,
+      .error = 0,
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(mode, nodeid_);
+  // Since this is only used in test, nodeid_ is simply increased by 1 to
+  // comply with the unqiueness of different path.
+  ++nodeid_;
+
+  // Set the size.
+  out_payload.attr.size = size;
+
+  memcpy(buf.data(), &out_header, sizeof(out_header));
+  memcpy(buf.data() + sizeof(out_header), &out_payload, sizeof(out_payload));
+  lookups_.AddMemBlock(FUSE_LOOKUP, buf.data(), out_len);
+  lookup_map_[path] = lookups_.Next();
+}
+
+// Sends the received request pointed by current cursor and advances cursor.
+void FuseTest::ServerSendReceivedRequest() {
+  if (requests_.End()) {
+    FAIL() << "No more received request.";
+    return;
+  }
+  auto mem_block = requests_.Next();
+  EXPECT_THAT(
+      RetryEINTR(write)(sock_[1], requests_.DataAtOffset(mem_block.offset),
+                        mem_block.len),
+      SyscallSucceedsWithValue(mem_block.len));
+}
+
+// Skip the request pointed by current cursor.
+void FuseTest::ServerSkipReceivedRequest() {
+  if (requests_.End()) {
+    FAIL() << "No more received request.";
+    return;
+  }
+  requests_.Next();
+}
+
+// Handles FUSE request. Reads request from /dev/fuse, checks if it has the
+// same opcode as expected, and responds with the saved fake FUSE response.
+// The FUSE request is copied to the serial buffer and can be retrieved one-
+// by-one by calling GetServerActualRequest from testing thread.
+void FuseTest::ServerProcessFuseRequest() {
+  ssize_t len;
+  std::vector<char> buf(FUSE_MIN_READ_BUFFER);
+
+  // Read FUSE request.
+  EXPECT_THAT(len = RetryEINTR(read)(dev_fd_, buf.data(), buf.size()),
+              SyscallSucceeds());
+  fuse_in_header* in_header = reinterpret_cast<fuse_in_header*>(buf.data());
+
+  // Check if this is a preset FUSE_LOOKUP path.
+  if (in_header->opcode == FUSE_LOOKUP) {
+    std::string path(buf.data() + sizeof(struct fuse_in_header));
+    auto it = lookup_map_.find(path);
+    if (it != lookup_map_.end()) {
+      // Matches a preset path. Reply with fake data and skip saving the
+      // request.
+      ServerRespondFuseSuccess(lookups_, it->second, in_header->unique);
+      return;
+    }
+  }
+
+  requests_.AddMemBlock(in_header->opcode, buf.data(), len);
+
+  if (in_header->opcode == FUSE_RELEASE || in_header->opcode == FUSE_RELEASEDIR)
+    return;
+  // Check if there is a corresponding response.
+  if (responses_.End()) {
+    GTEST_NONFATAL_FAILURE_("No more FUSE response is expected");
+    ServerRespondFuseError(in_header->unique);
+    return;
+  }
+  auto mem_block = responses_.Next();
+  if (in_header->opcode != mem_block.opcode) {
+    std::string message = absl::StrFormat("Expect opcode %d but got %d",
+                                          mem_block.opcode, in_header->opcode);
+    GTEST_NONFATAL_FAILURE_(message.c_str());
+    // We won't get correct response if opcode is not expected. Send error
+    // response here to avoid wrong parsing by VFS.
+    ServerRespondFuseError(in_header->unique);
+    return;
+  }
+
+  // Write FUSE response.
+  ServerRespondFuseSuccess(responses_, mem_block, in_header->unique);
+}
+
+void FuseTest::ServerRespondFuseSuccess(FuseMemBuffer& mem_buf,
+                                        const FuseMemBlock& block,
+                                        uint64_t unique) {
+  fuse_out_header* out_header =
+      reinterpret_cast<fuse_out_header*>(mem_buf.DataAtOffset(block.offset));
+
+  // Patch `unique` in fuse_out_header to avoid EINVAL caused by responding
+  // with an unknown `unique`.
+  out_header->unique = unique;
+  EXPECT_THAT(RetryEINTR(write)(dev_fd_, out_header, block.len),
+              SyscallSucceedsWithValue(block.len));
+}
+
+void FuseTest::ServerRespondFuseError(uint64_t unique) {
+  fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header),
+      .error = ENOSYS,
+      .unique = unique,
+  };
+  EXPECT_THAT(RetryEINTR(write)(dev_fd_, &out_header, sizeof(out_header)),
+              SyscallSucceedsWithValue(sizeof(out_header)));
 }
 
 }  // namespace testing
diff --git a/test/fuse/linux/fuse_base.h b/test/fuse/linux/fuse_base.h
index 3a2f255a9..6ad296ca2 100644
--- a/test/fuse/linux/fuse_base.h
+++ b/test/fuse/linux/fuse_base.h
@@ -16,8 +16,12 @@
 #define GVISOR_TEST_FUSE_FUSE_BASE_H_
 
 #include <linux/fuse.h>
+#include <string.h>
+#include <sys/stat.h>
 #include <sys/uio.h>
 
+#include <iostream>
+#include <unordered_map>
 #include <vector>
 
 #include "gtest/gtest.h"
@@ -29,68 +33,216 @@ namespace testing {
 
 constexpr char kMountOpts[] = "rootmode=755,user_id=0,group_id=0";
 
-class FuseTest : public ::testing::Test {
+constexpr struct fuse_init_out kDefaultFUSEInitOutPayload = {.major = 7};
+
+// Internal commands used to communicate between testing thread and the FUSE
+// server. See test/fuse/README.md for further detail.
+enum class FuseTestCmd {
+  kSetResponse = 0,
+  kSetInodeLookup,
+  kGetRequest,
+  kGetNumUnconsumedRequests,
+  kGetNumUnsentResponses,
+  kGetTotalReceivedBytes,
+  kSkipRequest,
+};
+
+// Holds the information of a memory block in a serial buffer.
+struct FuseMemBlock {
+  uint32_t opcode;
+  size_t offset;
+  size_t len;
+};
+
+// A wrapper of a simple serial buffer that can be used with read(2) and
+// write(2). Contains a cursor to indicate accessing. This class is not thread-
+// safe and can only be used in single-thread version.
+class FuseMemBuffer {
  public:
-  FuseTest() {
-    buf_.resize(FUSE_MIN_READ_BUFFER);
-    mem_in_.resize(FUSE_MIN_READ_BUFFER);
-    mem_out_.resize(FUSE_MIN_READ_BUFFER);
+  FuseMemBuffer() : cursor_(0) {
+    // To read from /dev/fuse, a buffer needs at least FUSE_MIN_READ_BUFFER
+    // bytes to avoid EINVAL. FuseMemBuffer holds memory that can accommodate
+    // a sequence of FUSE request/response, so it is initiated with double
+    // minimal requirement.
+    mem_.resize(FUSE_MIN_READ_BUFFER * 2);
   }
-  void SetUp() override;
-  void TearDown() override;
 
-  // CompareRequest is used by the FUSE server and should be implemented to
-  // compare different FUSE operations. It compares the actual FUSE input
-  // request with the expected one set by `SetExpected()`.
-  virtual bool CompareRequest(void* expected_mem, size_t expected_len,
-                              void* real_mem, size_t real_len);
+  // Returns whether there is no memory block.
+  bool Empty() { return blocks_.empty(); }
+
+  // Returns if there is no more remaining memory blocks.
+  bool End() { return cursor_ == blocks_.size(); }
+
+  // Returns how many bytes that have been received.
+  size_t UsedBytes() {
+    return Empty() ? 0 : blocks_.back().offset + blocks_.back().len;
+  }
+
+  // Returns the available bytes remains in the serial buffer.
+  size_t AvailBytes() { return mem_.size() - UsedBytes(); }
+
+  // Appends a memory block information that starts at the tail of the serial
+  // buffer. /dev/fuse requires at least FUSE_MIN_READ_BUFFER bytes to read, or
+  // it will issue EINVAL. If it is not enough, just double the buffer length.
+  void AddMemBlock(uint32_t opcode, void* data, size_t len) {
+    if (AvailBytes() < FUSE_MIN_READ_BUFFER) {
+      mem_.resize(mem_.size() << 1);
+    }
+    size_t offset = UsedBytes();
+    memcpy(mem_.data() + offset, data, len);
+    blocks_.push_back(FuseMemBlock{opcode, offset, len});
+  }
+
+  // Returns the memory address at a specific offset. Used with read(2) or
+  // write(2).
+  char* DataAtOffset(size_t offset) { return mem_.data() + offset; }
+
+  // Returns current memory block pointed by the cursor and increase by 1.
+  FuseMemBlock Next() {
+    if (End()) {
+      std::cerr << "Buffer is already exhausted." << std::endl;
+      return FuseMemBlock{};
+    }
+    return blocks_[cursor_++];
+  }
+
+  // Returns the number of the blocks that has not been requested.
+  size_t RemainingBlocks() { return blocks_.size() - cursor_; }
+
+ private:
+  size_t cursor_;
+  std::vector<FuseMemBlock> blocks_;
+  std::vector<char> mem_;
+};
 
-  // SetExpected is called by the testing main thread. Writes a request-
-  // response pair into FUSE server's member variables via pipe.
-  void SetExpected(struct iovec* iov_in, int iov_in_cnt, struct iovec* iov_out,
-                   int iov_out_cnt);
+// FuseTest base class is useful in FUSE integration test. Inherit this class
+// to automatically set up a fake FUSE server and use the member functions
+// to manipulate with it. Refer to test/fuse/README.md for detailed explanation.
+class FuseTest : public ::testing::Test {
+ public:
+  // nodeid_ is the ID of a fake inode. We starts from 2 since 1 is occupied by
+  // the mount point.
+  FuseTest() : nodeid_(2) {}
+  void SetUp() override;
+  void TearDown() override;
 
-  // WaitCompleted waits for FUSE server to complete its processing. It
-  // complains if the FUSE server responds failure during tests.
-  void WaitCompleted();
+  // Called by the testing thread to set up a fake response for an expected
+  // opcode via socket. This can be used multiple times to define a sequence of
+  // expected FUSE reactions.
+  void SetServerResponse(uint32_t opcode, std::vector<struct iovec>& iovecs);
+
+  // Called by the testing thread to install a fake path under the mount point.
+  // e.g. a file under /mnt/dir/file and moint point is /mnt, then it will look
+  // up "dir/file" in this case.
+  //
+  // It sets a fixed response to the FUSE_LOOKUP requests issued with this
+  // path, pretending there is an inode and avoid ENOENT when testing. If mode
+  // is not given, it creates a regular file with mode 0600.
+  void SetServerInodeLookup(const std::string& path,
+                            mode_t mode = S_IFREG | S_IRUSR | S_IWUSR,
+                            uint64_t size = 512);
+
+  // Called by the testing thread to ask the FUSE server for its next received
+  // FUSE request. Be sure to use the corresponding struct of iovec to receive
+  // data from server.
+  void GetServerActualRequest(std::vector<struct iovec>& iovecs);
+
+  // Called by the testing thread to query the number of unconsumed requests in
+  // the requests_ serial buffer of the FUSE server. TearDown() ensures all
+  // FUSE requests received by the FUSE server were consumed by the testing
+  // thread.
+  uint32_t GetServerNumUnconsumedRequests();
+
+  // Called by the testing thread to query the number of unsent responses in
+  // the responses_ serial buffer of the FUSE server. TearDown() ensures all
+  // preset FUSE responses were sent out by the FUSE server.
+  uint32_t GetServerNumUnsentResponses();
+
+  // Called by the testing thread to ask the FUSE server for its total received
+  // bytes from /dev/fuse.
+  uint32_t GetServerTotalReceivedBytes();
+
+  // Called by the testing thread to ask the FUSE server to skip stored
+  // request data.
+  void SkipServerActualRequest();
 
  protected:
   TempPath mount_point_;
 
- private:
-  void MountFuse();
+  // Opens /dev/fuse and inherit the file descriptor for the FUSE server.
+  void MountFuse(const char* mountOpts = kMountOpts);
+
+  // Creates a socketpair for communication and forks FUSE server.
+  void SetUpFuseServer(
+      const struct fuse_init_out* payload = &kDefaultFUSEInitOutPayload);
+
+  // Unmounts the mountpoint of the FUSE server.
   void UnmountFuse();
 
-  // ConsumeFuseInit is only used during FUSE server setup.
-  PosixError ConsumeFuseInit();
+ private:
+  // Sends a FuseTestCmd and gets a uint32_t data from the FUSE server.
+  inline uint32_t GetServerData(uint32_t cmd);
+
+  // Waits for FUSE server to complete its processing. Complains if the FUSE
+  // server responds any failure during tests.
+  void WaitServerComplete();
 
-  // ReceiveExpected is the FUSE server side's corresponding code of
-  // `SetExpected()`. Save the request-response pair into its memory.
-  void ReceiveExpected();
+  // The FUSE server stays here and waits next command or FUSE request until it
+  // is terminated.
+  void ServerFuseLoop();
 
-  // MarkDone is used by the FUSE server to tell testing main if it's OK to
-  // proceed next command.
-  void MarkDone(bool success);
+  // Used by the FUSE server to tell testing thread if it is OK to proceed next
+  // command. Will be issued after processing each FuseTestCmd.
+  void ServerCompleteWith(bool success);
 
-  // FuseLoop is where the FUSE server stay until it is terminated.
-  void FuseLoop();
+  // Consumes the first FUSE request when mounting FUSE. Replies with a
+  // response with empty payload.
+  PosixError ServerConsumeFuseInit(const struct fuse_init_out* payload);
 
-  // SetUpFuseServer creates 2 pipes for communication and forks FUSE server.
-  void SetUpFuseServer();
+  // A command switch that dispatch different FuseTestCmd to its handler.
+  void ServerHandleCommand();
 
-  // GetPayloadSize is a helper function to get the number of bytes of a
-  // specific FUSE operation struct.
-  size_t GetPayloadSize(uint32_t opcode, bool in);
+  // The FUSE server side's corresponding code of `SetServerResponse()`.
+  // Handles `kSetResponse` command. Saves the fake response into its output
+  // memory queue.
+  void ServerReceiveResponse();
+
+  // The FUSE server side's corresponding code of `SetServerInodeLookup()`.
+  // Handles `kSetInodeLookup` command. Receives an expected file mode and
+  // file path under the mount point.
+  void ServerReceiveInodeLookup();
+
+  // The FUSE server side's corresponding code of `GetServerActualRequest()`.
+  // Handles `kGetRequest` command. Sends the next received request pointed by
+  // the cursor.
+  void ServerSendReceivedRequest();
+
+  // Sends a uint32_t data via socket.
+  inline void ServerSendData(uint32_t data);
+
+  // The FUSE server side's corresponding code of `SkipServerActualRequest()`.
+  // Handles `kSkipRequest` command. Skip the request pointed by current cursor.
+  void ServerSkipReceivedRequest();
+
+  // Handles FUSE request sent to /dev/fuse by its saved responses.
+  void ServerProcessFuseRequest();
+
+  // Responds to FUSE request with a saved data.
+  void ServerRespondFuseSuccess(FuseMemBuffer& mem_buf,
+                                const FuseMemBlock& block, uint64_t unique);
+
+  // Responds an error header to /dev/fuse when bad thing happens.
+  void ServerRespondFuseError(uint64_t unique);
 
   int dev_fd_;
-  int set_expected_[2];
-  int done_[2];
-
-  std::vector<char> buf_;
-  std::vector<char> mem_in_;
-  std::vector<char> mem_out_;
-  ssize_t len_in_;
-  ssize_t len_out_;
+  int sock_[2];
+
+  uint64_t nodeid_;
+  std::unordered_map<std::string, FuseMemBlock> lookup_map_;
+
+  FuseMemBuffer requests_;
+  FuseMemBuffer responses_;
+  FuseMemBuffer lookups_;
 };
 
 }  // namespace testing
diff --git a/test/fuse/linux/fuse_fd_util.cc b/test/fuse/linux/fuse_fd_util.cc
new file mode 100644
index 000000000..30d1157bb
--- /dev/null
+++ b/test/fuse/linux/fuse_fd_util.cc
@@ -0,0 +1,61 @@
+// Copyright 2020 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.
+
+#include "test/fuse/linux/fuse_fd_util.h"
+
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include <string>
+#include <vector>
+
+#include "test/util/cleanup.h"
+#include "test/util/file_descriptor.h"
+#include "test/util/fuse_util.h"
+#include "test/util/posix_error.h"
+
+namespace gvisor {
+namespace testing {
+
+PosixErrorOr<FileDescriptor> FuseFdTest::OpenPath(const std::string &path,
+                                                  uint32_t flags, uint64_t fh) {
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+  };
+  struct fuse_open_out out_payload = {
+      .fh = fh,
+      .open_flags = flags,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_OPEN, iov_out);
+
+  auto res = Open(path.c_str(), flags);
+  if (res.ok()) {
+    SkipServerActualRequest();
+  }
+  return res;
+}
+
+Cleanup FuseFdTest::CloseFD(FileDescriptor &fd) {
+  return Cleanup([&] {
+    close(fd.release());
+    SkipServerActualRequest();
+  });
+}
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/fuse_fd_util.h b/test/fuse/linux/fuse_fd_util.h
new file mode 100644
index 000000000..066185c94
--- /dev/null
+++ b/test/fuse/linux/fuse_fd_util.h
@@ -0,0 +1,48 @@
+// Copyright 2020 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.
+
+#ifndef GVISOR_TEST_FUSE_FUSE_FD_UTIL_H_
+#define GVISOR_TEST_FUSE_FUSE_FD_UTIL_H_
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/cleanup.h"
+#include "test/util/file_descriptor.h"
+#include "test/util/posix_error.h"
+
+namespace gvisor {
+namespace testing {
+
+class FuseFdTest : public FuseTest {
+ public:
+  // Sets the FUSE server to respond to a FUSE_OPEN with corresponding flags and
+  // fh. Then does a real file system open on the absolute path to get an fd.
+  PosixErrorOr<FileDescriptor> OpenPath(const std::string &path,
+                                        uint32_t flags = O_RDONLY,
+                                        uint64_t fh = 1);
+
+  // Returns a cleanup object that closes the fd when it is destroyed. After
+  // the close is done, tells the FUSE server to skip this FUSE_RELEASE.
+  Cleanup CloseFD(FileDescriptor &fd);
+};
+
+}  // namespace testing
+}  // namespace gvisor
+
+#endif  // GVISOR_TEST_FUSE_FUSE_FD_UTIL_H_
diff --git a/test/fuse/linux/mkdir_test.cc b/test/fuse/linux/mkdir_test.cc
new file mode 100644
index 000000000..9647cb93f
--- /dev/null
+++ b/test/fuse/linux/mkdir_test.cc
@@ -0,0 +1,88 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/temp_umask.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class MkdirTest : public FuseTest {
+ protected:
+  const std::string test_dir_ = "test_dir";
+  const mode_t perms_ = S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(MkdirTest, CreateDir) {
+  const std::string test_dir_path_ =
+      JoinPath(mount_point_.path().c_str(), test_dir_);
+  const mode_t new_umask = 0077;
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFDIR | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_MKDIR, iov_out);
+  TempUmask mask(new_umask);
+  ASSERT_THAT(mkdir(test_dir_path_.c_str(), 0777), SyscallSucceeds());
+
+  struct fuse_in_header in_header;
+  struct fuse_mkdir_in in_payload;
+  std::vector<char> actual_dir(test_dir_.length() + 1);
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload, actual_dir);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len,
+            sizeof(in_header) + sizeof(in_payload) + test_dir_.length() + 1);
+  EXPECT_EQ(in_header.opcode, FUSE_MKDIR);
+  EXPECT_EQ(in_payload.mode & 0777, perms_ & ~new_umask);
+  EXPECT_EQ(in_payload.umask, new_umask);
+  EXPECT_EQ(std::string(actual_dir.data()), test_dir_);
+}
+
+TEST_F(MkdirTest, FileTypeError) {
+  const std::string test_dir_path_ =
+      JoinPath(mount_point_.path().c_str(), test_dir_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFREG | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_MKDIR, iov_out);
+  ASSERT_THAT(mkdir(test_dir_path_.c_str(), 0777), SyscallFailsWithErrno(EIO));
+  SkipServerActualRequest();
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/mknod_test.cc b/test/fuse/linux/mknod_test.cc
new file mode 100644
index 000000000..74c74d76b
--- /dev/null
+++ b/test/fuse/linux/mknod_test.cc
@@ -0,0 +1,107 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/temp_umask.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class MknodTest : public FuseTest {
+ protected:
+  const std::string test_file_ = "test_file";
+  const mode_t perms_ = S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(MknodTest, RegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  const mode_t new_umask = 0077;
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFREG | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_MKNOD, iov_out);
+  TempUmask mask(new_umask);
+  ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0), SyscallSucceeds());
+
+  struct fuse_in_header in_header;
+  struct fuse_mknod_in in_payload;
+  std::vector<char> actual_file(test_file_.length() + 1);
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload, actual_file);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len,
+            sizeof(in_header) + sizeof(in_payload) + test_file_.length() + 1);
+  EXPECT_EQ(in_header.opcode, FUSE_MKNOD);
+  EXPECT_EQ(in_payload.mode & 0777, perms_ & ~new_umask);
+  EXPECT_EQ(in_payload.umask, new_umask);
+  EXPECT_EQ(in_payload.rdev, 0);
+  EXPECT_EQ(std::string(actual_file.data()), test_file_);
+}
+
+TEST_F(MknodTest, FileTypeError) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  // server return directory instead of regular file should cause an error.
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFDIR | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_MKNOD, iov_out);
+  ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0),
+              SyscallFailsWithErrno(EIO));
+  SkipServerActualRequest();
+}
+
+TEST_F(MknodTest, NodeIDError) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload =
+      DefaultEntryOut(S_IFREG | perms_, FUSE_ROOT_ID);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_MKNOD, iov_out);
+  ASSERT_THAT(mknod(test_file_path.c_str(), perms_, 0),
+              SyscallFailsWithErrno(EIO));
+  SkipServerActualRequest();
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/open_test.cc b/test/fuse/linux/open_test.cc
new file mode 100644
index 000000000..4b0c4a805
--- /dev/null
+++ b/test/fuse/linux/open_test.cc
@@ -0,0 +1,128 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class OpenTest : public FuseTest {
+  // OpenTest doesn't care the release request when close a fd,
+  // so doesn't check leftover requests when tearing down.
+  void TearDown() { UnmountFuse(); }
+
+ protected:
+  const std::string test_file_ = "test_file";
+  const mode_t regular_file_ = S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO;
+
+  struct fuse_open_out out_payload_ = {
+      .fh = 1,
+      .open_flags = O_RDWR,
+  };
+};
+
+TEST_F(OpenTest, RegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, regular_file_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPEN, iov_out);
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+
+  struct fuse_in_header in_header;
+  struct fuse_open_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_OPEN);
+  EXPECT_EQ(in_payload.flags, O_RDWR);
+  EXPECT_THAT(fcntl(fd.get(), F_GETFL), SyscallSucceedsWithValue(O_RDWR));
+}
+
+TEST_F(OpenTest, SetNoOpen) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, regular_file_);
+
+  // ENOSYS indicates open is not implemented.
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+      .error = -ENOSYS,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPEN, iov_out);
+  ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+  SkipServerActualRequest();
+
+  // check open doesn't send new request.
+  uint32_t recieved_before = GetServerTotalReceivedBytes();
+  ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+  EXPECT_EQ(GetServerTotalReceivedBytes(), recieved_before);
+}
+
+TEST_F(OpenTest, OpenFail) {
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+      .error = -ENOENT,
+  };
+
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPENDIR, iov_out);
+  ASSERT_THAT(open(mount_point_.path().c_str(), O_RDWR),
+              SyscallFailsWithErrno(ENOENT));
+
+  struct fuse_in_header in_header;
+  struct fuse_open_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_OPENDIR);
+  EXPECT_EQ(in_payload.flags, O_RDWR);
+}
+
+TEST_F(OpenTest, DirectoryFlagOnRegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+
+  SetServerInodeLookup(test_file_, regular_file_);
+  ASSERT_THAT(open(test_file_path.c_str(), O_RDWR | O_DIRECTORY),
+              SyscallFailsWithErrno(ENOTDIR));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/read_test.cc b/test/fuse/linux/read_test.cc
new file mode 100644
index 000000000..88fc299d8
--- /dev/null
+++ b/test/fuse/linux/read_test.cc
@@ -0,0 +1,390 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class ReadTest : public FuseTest {
+  void SetUp() override {
+    FuseTest::SetUp();
+    test_file_path_ = JoinPath(mount_point_.path().c_str(), test_file_);
+  }
+
+  // TearDown overrides the parent's function
+  // to skip checking the unconsumed release request at the end.
+  void TearDown() override { UnmountFuse(); }
+
+ protected:
+  const std::string test_file_ = "test_file";
+  const mode_t test_file_mode_ = S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO;
+  const uint64_t test_fh_ = 1;
+  const uint32_t open_flag_ = O_RDWR;
+
+  std::string test_file_path_;
+
+  PosixErrorOr<FileDescriptor> OpenTestFile(const std::string &path,
+                                            uint64_t size = 512) {
+    SetServerInodeLookup(test_file_, test_file_mode_, size);
+
+    struct fuse_out_header out_header_open = {
+        .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+    };
+    struct fuse_open_out out_payload_open = {
+        .fh = test_fh_,
+        .open_flags = open_flag_,
+    };
+    auto iov_out_open = FuseGenerateIovecs(out_header_open, out_payload_open);
+    SetServerResponse(FUSE_OPEN, iov_out_open);
+
+    auto res = Open(path.c_str(), open_flag_);
+    if (res.ok()) {
+      SkipServerActualRequest();
+    }
+    return res;
+  }
+};
+
+class ReadTestSmallMaxRead : public ReadTest {
+  void SetUp() override {
+    MountFuse(mountOpts);
+    SetUpFuseServer();
+    test_file_path_ = JoinPath(mount_point_.path().c_str(), test_file_);
+  }
+
+ protected:
+  constexpr static char mountOpts[] =
+      "rootmode=755,user_id=0,group_id=0,max_read=4096";
+  // 4096 is hard-coded as the max_read in mount options.
+  const int size_fragment = 4096;
+};
+
+TEST_F(ReadTest, ReadWhole) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the read.
+  const int n_read = 5;
+  std::vector<char> data(n_read);
+  RandomizeBuffer(data.data(), data.size());
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+  SetServerResponse(FUSE_READ, iov_out_read);
+
+  // Read the whole "file".
+  std::vector<char> buf(n_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), n_read),
+              SyscallSucceedsWithValue(n_read));
+
+  // Check the read request.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_header_read.len,
+            sizeof(in_header_read) + sizeof(in_payload_read));
+  EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+  EXPECT_EQ(in_payload_read.offset, 0);
+  EXPECT_EQ(buf, data);
+}
+
+TEST_F(ReadTest, ReadPartial) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the read.
+  const int n_data = 10;
+  std::vector<char> data(n_data);
+  RandomizeBuffer(data.data(), data.size());
+  // Note: due to read ahead, current read implementation will treat any
+  // response that is longer than requested as correct (i.e. not reach the EOF).
+  // Therefore, the test below should make sure the size to read does not exceed
+  // n_data.
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+
+  std::vector<char> buf(n_data);
+
+  // Read 1 bytes.
+  SetServerResponse(FUSE_READ, iov_out_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), 1), SyscallSucceedsWithValue(1));
+
+  // Check the 1-byte read request.
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_header_read.len,
+            sizeof(in_header_read) + sizeof(in_payload_read));
+  EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+  EXPECT_EQ(in_payload_read.offset, 0);
+
+  // Read 3 bytes.
+  SetServerResponse(FUSE_READ, iov_out_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), 3), SyscallSucceedsWithValue(3));
+
+  // Check the 3-byte read request.
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_payload_read.offset, 1);
+
+  // Read 5 bytes.
+  SetServerResponse(FUSE_READ, iov_out_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), 5), SyscallSucceedsWithValue(5));
+
+  // Check the 5-byte read request.
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_payload_read.offset, 4);
+}
+
+TEST_F(ReadTest, PRead) {
+  const int file_size = 512;
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_, file_size));
+
+  // Prepare for the read.
+  const int n_read = 5;
+  std::vector<char> data(n_read);
+  RandomizeBuffer(data.data(), data.size());
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+  SetServerResponse(FUSE_READ, iov_out_read);
+
+  // Read some bytes.
+  std::vector<char> buf(n_read);
+  const int offset_read = file_size >> 1;
+  EXPECT_THAT(pread(fd.get(), buf.data(), n_read, offset_read),
+              SyscallSucceedsWithValue(n_read));
+
+  // Check the read request.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_header_read.len,
+            sizeof(in_header_read) + sizeof(in_payload_read));
+  EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+  EXPECT_EQ(in_payload_read.offset, offset_read);
+  EXPECT_EQ(buf, data);
+}
+
+TEST_F(ReadTest, ReadZero) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Issue the read.
+  std::vector<char> buf;
+  EXPECT_THAT(read(fd.get(), buf.data(), 0), SyscallSucceedsWithValue(0));
+}
+
+TEST_F(ReadTest, ReadShort) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the short read.
+  const int n_read = 5;
+  std::vector<char> data(n_read >> 1);
+  RandomizeBuffer(data.data(), data.size());
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+  SetServerResponse(FUSE_READ, iov_out_read);
+
+  // Read the whole "file".
+  std::vector<char> buf(n_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), n_read),
+              SyscallSucceedsWithValue(data.size()));
+
+  // Check the read request.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_header_read.len,
+            sizeof(in_header_read) + sizeof(in_payload_read));
+  EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+  EXPECT_EQ(in_payload_read.offset, 0);
+  std::vector<char> short_buf(buf.begin(), buf.begin() + data.size());
+  EXPECT_EQ(short_buf, data);
+}
+
+TEST_F(ReadTest, ReadShortEOF) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the short read.
+  struct fuse_out_header out_header_read = {
+      .len = static_cast<uint32_t>(sizeof(struct fuse_out_header)),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read);
+  SetServerResponse(FUSE_READ, iov_out_read);
+
+  // Read the whole "file".
+  const int n_read = 10;
+  std::vector<char> buf(n_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), n_read), SyscallSucceedsWithValue(0));
+
+  // Check the read request.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_payload_read.fh, test_fh_);
+  EXPECT_EQ(in_header_read.len,
+            sizeof(in_header_read) + sizeof(in_payload_read));
+  EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+  EXPECT_EQ(in_payload_read.offset, 0);
+}
+
+TEST_F(ReadTestSmallMaxRead, ReadSmallMaxRead) {
+  const int n_fragment = 10;
+  const int n_read = size_fragment * n_fragment;
+
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_, n_read));
+
+  // Prepare for the read.
+  std::vector<char> data(size_fragment);
+  RandomizeBuffer(data.data(), data.size());
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+
+  for (int i = 0; i < n_fragment; ++i) {
+    SetServerResponse(FUSE_READ, iov_out_read);
+  }
+
+  // Read the whole "file".
+  std::vector<char> buf(n_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), n_read),
+              SyscallSucceedsWithValue(n_read));
+
+  ASSERT_EQ(GetServerNumUnsentResponses(), 0);
+  ASSERT_EQ(GetServerNumUnconsumedRequests(), n_fragment);
+
+  // Check each read segment.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+
+  for (int i = 0; i < n_fragment; ++i) {
+    GetServerActualRequest(iov_in);
+    EXPECT_EQ(in_payload_read.fh, test_fh_);
+    EXPECT_EQ(in_header_read.len,
+              sizeof(in_header_read) + sizeof(in_payload_read));
+    EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+    EXPECT_EQ(in_payload_read.offset, i * size_fragment);
+    EXPECT_EQ(in_payload_read.size, size_fragment);
+
+    auto it = buf.begin() + i * size_fragment;
+    EXPECT_EQ(std::vector<char>(it, it + size_fragment), data);
+  }
+}
+
+TEST_F(ReadTestSmallMaxRead, ReadSmallMaxReadShort) {
+  const int n_fragment = 10;
+  const int n_read = size_fragment * n_fragment;
+
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_, n_read));
+
+  // Prepare for the read.
+  std::vector<char> data(size_fragment);
+  RandomizeBuffer(data.data(), data.size());
+  struct fuse_out_header out_header_read = {
+      .len =
+          static_cast<uint32_t>(sizeof(struct fuse_out_header) + data.size()),
+  };
+  auto iov_out_read = FuseGenerateIovecs(out_header_read, data);
+
+  for (int i = 0; i < n_fragment - 1; ++i) {
+    SetServerResponse(FUSE_READ, iov_out_read);
+  }
+
+  // The last fragment is a short read.
+  std::vector<char> half_data(data.begin(), data.begin() + (data.size() >> 1));
+  struct fuse_out_header out_header_read_short = {
+      .len = static_cast<uint32_t>(sizeof(struct fuse_out_header) +
+                                   half_data.size()),
+  };
+  auto iov_out_read_short =
+      FuseGenerateIovecs(out_header_read_short, half_data);
+  SetServerResponse(FUSE_READ, iov_out_read_short);
+
+  // Read the whole "file".
+  std::vector<char> buf(n_read);
+  EXPECT_THAT(read(fd.get(), buf.data(), n_read),
+              SyscallSucceedsWithValue(n_read - (data.size() >> 1)));
+
+  ASSERT_EQ(GetServerNumUnsentResponses(), 0);
+  ASSERT_EQ(GetServerNumUnconsumedRequests(), n_fragment);
+
+  // Check each read segment.
+  struct fuse_in_header in_header_read;
+  struct fuse_read_in in_payload_read;
+  auto iov_in = FuseGenerateIovecs(in_header_read, in_payload_read);
+
+  for (int i = 0; i < n_fragment; ++i) {
+    GetServerActualRequest(iov_in);
+    EXPECT_EQ(in_payload_read.fh, test_fh_);
+    EXPECT_EQ(in_header_read.len,
+              sizeof(in_header_read) + sizeof(in_payload_read));
+    EXPECT_EQ(in_header_read.opcode, FUSE_READ);
+    EXPECT_EQ(in_payload_read.offset, i * size_fragment);
+    EXPECT_EQ(in_payload_read.size, size_fragment);
+
+    auto it = buf.begin() + i * size_fragment;
+    if (i != n_fragment - 1) {
+      EXPECT_EQ(std::vector<char>(it, it + data.size()), data);
+    } else {
+      EXPECT_EQ(std::vector<char>(it, it + half_data.size()), half_data);
+    }
+  }
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/readdir_test.cc b/test/fuse/linux/readdir_test.cc
new file mode 100644
index 000000000..2afb4b062
--- /dev/null
+++ b/test/fuse/linux/readdir_test.cc
@@ -0,0 +1,193 @@
+// Copyright 2020 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.
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <linux/unistd.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
+#define FUSE_DIRENT_ALIGN(x) \
+  (((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
+#define FUSE_DIRENT_SIZE(d) FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class ReaddirTest : public FuseTest {
+ public:
+  void fill_fuse_dirent(char *buf, const char *name, uint64_t ino) {
+    size_t namelen = strlen(name);
+    size_t entlen = FUSE_NAME_OFFSET + namelen;
+    size_t entlen_padded = FUSE_DIRENT_ALIGN(entlen);
+    struct fuse_dirent *dirent;
+
+    dirent = reinterpret_cast<struct fuse_dirent *>(buf);
+    dirent->ino = ino;
+    dirent->namelen = namelen;
+    memcpy(dirent->name, name, namelen);
+    memset(dirent->name + namelen, 0, entlen_padded - entlen);
+  }
+
+ protected:
+  const std::string test_dir_name_ = "test_dir";
+};
+
+TEST_F(ReaddirTest, SingleEntry) {
+  const std::string test_dir_path =
+      JoinPath(mount_point_.path().c_str(), test_dir_name_);
+
+  const uint64_t ino_dir = 1024;
+  // We need to make sure the test dir is a directory that can be found.
+  mode_t expected_mode =
+      S_IFDIR | S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
+  struct fuse_attr dir_attr = {
+      .ino = ino_dir,
+      .size = 512,
+      .blocks = 4,
+      .mode = expected_mode,
+      .blksize = 4096,
+  };
+
+  // We need to make sure the test dir is a directory that can be found.
+  struct fuse_out_header lookup_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out lookup_payload = {
+      .nodeid = 1,
+      .entry_valid = true,
+      .attr_valid = true,
+      .attr = dir_attr,
+  };
+
+  struct fuse_out_header open_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+  };
+  struct fuse_open_out open_payload = {
+      .fh = 1,
+  };
+  auto iov_out = FuseGenerateIovecs(lookup_header, lookup_payload);
+  SetServerResponse(FUSE_LOOKUP, iov_out);
+
+  iov_out = FuseGenerateIovecs(open_header, open_payload);
+  SetServerResponse(FUSE_OPENDIR, iov_out);
+
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(Open(test_dir_path.c_str(), O_RDONLY));
+
+  // The open command makes two syscalls. Lookup the dir file and open.
+  // We don't need to inspect those headers in this test.
+  SkipServerActualRequest();  // LOOKUP.
+  SkipServerActualRequest();  // OPENDIR.
+
+  // Readdir test code.
+  std::string dot = ".";
+  std::string dot_dot = "..";
+  std::string test_file = "testFile";
+
+  // Figure out how many dirents to send over and allocate them appropriately.
+  // Each dirent has a dynamic name and a static metadata part. The dirent size
+  // is aligned to being a multiple of 8.
+  size_t dot_file_dirent_size =
+      FUSE_DIRENT_ALIGN(dot.length() + FUSE_NAME_OFFSET);
+  size_t dot_dot_file_dirent_size =
+      FUSE_DIRENT_ALIGN(dot_dot.length() + FUSE_NAME_OFFSET);
+  size_t test_file_dirent_size =
+      FUSE_DIRENT_ALIGN(test_file.length() + FUSE_NAME_OFFSET);
+
+  // Create an appropriately sized payload.
+  size_t readdir_payload_size =
+      test_file_dirent_size + dot_file_dirent_size + dot_dot_file_dirent_size;
+  std::vector<char> readdir_payload_vec(readdir_payload_size);
+  char *readdir_payload = readdir_payload_vec.data();
+
+  // Use fake ino for other directories.
+  fill_fuse_dirent(readdir_payload, dot.c_str(), ino_dir - 2);
+  fill_fuse_dirent(readdir_payload + dot_file_dirent_size, dot_dot.c_str(),
+                   ino_dir - 1);
+  fill_fuse_dirent(
+      readdir_payload + dot_file_dirent_size + dot_dot_file_dirent_size,
+      test_file.c_str(), ino_dir);
+
+  struct fuse_out_header readdir_header = {
+      .len = uint32_t(sizeof(struct fuse_out_header) + readdir_payload_size),
+  };
+  struct fuse_out_header readdir_header_break = {
+      .len = uint32_t(sizeof(struct fuse_out_header)),
+  };
+
+  iov_out = FuseGenerateIovecs(readdir_header, readdir_payload_vec);
+  SetServerResponse(FUSE_READDIR, iov_out);
+
+  iov_out = FuseGenerateIovecs(readdir_header_break);
+  SetServerResponse(FUSE_READDIR, iov_out);
+
+  std::vector<char> buf(4090, 0);
+  int nread, off = 0, i = 0;
+  EXPECT_THAT(
+      nread = syscall(__NR_getdents64, fd.get(), buf.data(), buf.size()),
+      SyscallSucceeds());
+  for (; off < nread;) {
+    struct dirent64 *ent = (struct dirent64 *)(buf.data() + off);
+    off += ent->d_reclen;
+    switch (i++) {
+      case 0:
+        EXPECT_EQ(std::string(ent->d_name), dot);
+        break;
+      case 1:
+        EXPECT_EQ(std::string(ent->d_name), dot_dot);
+        break;
+      case 2:
+        EXPECT_EQ(std::string(ent->d_name), test_file);
+        break;
+    }
+  }
+
+  EXPECT_THAT(
+      nread = syscall(__NR_getdents64, fd.get(), buf.data(), buf.size()),
+      SyscallSucceedsWithValue(0));
+
+  SkipServerActualRequest();  // READDIR.
+  SkipServerActualRequest();  // READDIR with no data.
+
+  // Clean up.
+  fd.reset(-1);
+
+  struct fuse_in_header in_header;
+  struct fuse_release_in in_payload;
+
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_RELEASEDIR);
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/readlink_test.cc b/test/fuse/linux/readlink_test.cc
new file mode 100644
index 000000000..2cba8fc23
--- /dev/null
+++ b/test/fuse/linux/readlink_test.cc
@@ -0,0 +1,85 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class ReadlinkTest : public FuseTest {
+ protected:
+  const std::string test_file_ = "test_file_";
+  const mode_t perms_ = S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(ReadlinkTest, ReadSymLink) {
+  const std::string symlink_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, S_IFLNK | perms_);
+
+  struct fuse_out_header out_header = {
+      .len = static_cast<uint32_t>(sizeof(struct fuse_out_header)) +
+             static_cast<uint32_t>(test_file_.length()) + 1,
+  };
+  std::string link = test_file_;
+  auto iov_out = FuseGenerateIovecs(out_header, link);
+  SetServerResponse(FUSE_READLINK, iov_out);
+  const std::string actual_link =
+      ASSERT_NO_ERRNO_AND_VALUE(ReadLink(symlink_path));
+
+  struct fuse_in_header in_header;
+  auto iov_in = FuseGenerateIovecs(in_header);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header));
+  EXPECT_EQ(in_header.opcode, FUSE_READLINK);
+  EXPECT_EQ(0, memcmp(actual_link.c_str(), link.data(), link.size()));
+
+  // next readlink should have link cached, so shouldn't have new request to
+  // server.
+  uint32_t recieved_before = GetServerTotalReceivedBytes();
+  ASSERT_NO_ERRNO(ReadLink(symlink_path));
+  EXPECT_EQ(GetServerTotalReceivedBytes(), recieved_before);
+}
+
+TEST_F(ReadlinkTest, NotSymlink) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, S_IFREG | perms_);
+
+  std::vector<char> buf(PATH_MAX + 1);
+  ASSERT_THAT(readlink(test_file_path.c_str(), buf.data(), PATH_MAX),
+              SyscallFailsWithErrno(EINVAL));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/release_test.cc b/test/fuse/linux/release_test.cc
new file mode 100644
index 000000000..b5adb0870
--- /dev/null
+++ b/test/fuse/linux/release_test.cc
@@ -0,0 +1,74 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class ReleaseTest : public FuseTest {
+ protected:
+  const std::string test_file_ = "test_file";
+};
+
+TEST_F(ReleaseTest, RegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+  };
+  struct fuse_open_out out_payload = {
+      .fh = 1,
+      .open_flags = O_RDWR,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_OPEN, iov_out);
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path, O_RDWR));
+  SkipServerActualRequest();
+  ASSERT_THAT(close(fd.release()), SyscallSucceeds());
+
+  struct fuse_in_header in_header;
+  struct fuse_release_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_RELEASE);
+  EXPECT_EQ(in_payload.flags, O_RDWR);
+  EXPECT_EQ(in_payload.fh, 1);
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/rmdir_test.cc b/test/fuse/linux/rmdir_test.cc
new file mode 100644
index 000000000..913d3f910
--- /dev/null
+++ b/test/fuse/linux/rmdir_test.cc
@@ -0,0 +1,73 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fs_util.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class RmDirTest : public FuseTest {
+ protected:
+  const std::string test_dir_name_ = "test_dir";
+  const mode_t test_dir_mode_ = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(RmDirTest, NormalRmDir) {
+  const std::string test_dir_path_ =
+      JoinPath(mount_point_.path().c_str(), test_dir_name_);
+
+  SetServerInodeLookup(test_dir_name_, test_dir_mode_);
+
+  // RmDir code.
+  struct fuse_out_header rmdir_header = {
+      .len = sizeof(struct fuse_out_header),
+  };
+
+  auto iov_out = FuseGenerateIovecs(rmdir_header);
+  SetServerResponse(FUSE_RMDIR, iov_out);
+
+  ASSERT_THAT(rmdir(test_dir_path_.c_str()), SyscallSucceeds());
+
+  struct fuse_in_header in_header;
+  std::vector<char> actual_dirname(test_dir_name_.length() + 1);
+  auto iov_in = FuseGenerateIovecs(in_header, actual_dirname);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + test_dir_name_.length() + 1);
+  EXPECT_EQ(in_header.opcode, FUSE_RMDIR);
+  EXPECT_EQ(std::string(actual_dirname.data()), test_dir_name_);
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/setstat_test.cc b/test/fuse/linux/setstat_test.cc
new file mode 100644
index 000000000..68301c775
--- /dev/null
+++ b/test/fuse/linux/setstat_test.cc
@@ -0,0 +1,338 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <unistd.h>
+#include <utime.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_fd_util.h"
+#include "test/util/cleanup.h"
+#include "test/util/fs_util.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class SetStatTest : public FuseFdTest {
+ public:
+  void SetUp() override {
+    FuseFdTest::SetUp();
+    test_dir_path_ = JoinPath(mount_point_.path(), test_dir_);
+    test_file_path_ = JoinPath(mount_point_.path(), test_file_);
+  }
+
+ protected:
+  const uint64_t fh = 23;
+  const std::string test_dir_ = "testdir";
+  const std::string test_file_ = "testfile";
+  const mode_t test_dir_mode_ = S_IFDIR | S_IRUSR | S_IWUSR | S_IXUSR;
+  const mode_t test_file_mode_ = S_IFREG | S_IRUSR | S_IWUSR | S_IXUSR;
+
+  std::string test_dir_path_;
+  std::string test_file_path_;
+};
+
+TEST_F(SetStatTest, ChmodDir) {
+  // Set up fixture.
+  SetServerInodeLookup(test_dir_, test_dir_mode_);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  mode_t set_mode = S_IRGRP | S_IWGRP | S_IXGRP;
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(set_mode, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(chmod(test_dir_path_.c_str(), set_mode), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_MODE);
+  EXPECT_EQ(in_payload.mode, S_IFDIR | set_mode);
+}
+
+TEST_F(SetStatTest, ChownDir) {
+  // Set up fixture.
+  SetServerInodeLookup(test_dir_, test_dir_mode_);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(test_dir_mode_, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(chown(test_dir_path_.c_str(), 1025, 1025), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_UID | FATTR_GID);
+  EXPECT_EQ(in_payload.uid, 1025);
+  EXPECT_EQ(in_payload.gid, 1025);
+}
+
+TEST_F(SetStatTest, TruncateFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(S_IFREG | S_IRUSR | S_IWUSR, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(truncate(test_file_path_.c_str(), 321), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_SIZE);
+  EXPECT_EQ(in_payload.size, 321);
+}
+
+TEST_F(SetStatTest, UtimeFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(S_IFREG | S_IRUSR | S_IWUSR, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  time_t expected_atime = 1597159766, expected_mtime = 1597159765;
+  struct utimbuf times = {
+      .actime = expected_atime,
+      .modtime = expected_mtime,
+  };
+  EXPECT_THAT(utime(test_file_path_.c_str(), &times), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_ATIME | FATTR_MTIME);
+  EXPECT_EQ(in_payload.atime, expected_atime);
+  EXPECT_EQ(in_payload.mtime, expected_mtime);
+}
+
+TEST_F(SetStatTest, UtimesFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(test_file_mode_, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  struct timeval expected_times[2] = {
+      {
+          .tv_sec = 1597159766,
+          .tv_usec = 234945,
+      },
+      {
+          .tv_sec = 1597159765,
+          .tv_usec = 232341,
+      },
+  };
+  EXPECT_THAT(utimes(test_file_path_.c_str(), expected_times),
+              SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_ATIME | FATTR_MTIME);
+  EXPECT_EQ(in_payload.atime, expected_times[0].tv_sec);
+  EXPECT_EQ(in_payload.atimensec, expected_times[0].tv_usec * 1000);
+  EXPECT_EQ(in_payload.mtime, expected_times[1].tv_sec);
+  EXPECT_EQ(in_payload.mtimensec, expected_times[1].tv_usec * 1000);
+}
+
+TEST_F(SetStatTest, FtruncateFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDWR, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(test_file_mode_, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(ftruncate(fd.get(), 321), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_SIZE | FATTR_FH);
+  EXPECT_EQ(in_payload.fh, fh);
+  EXPECT_EQ(in_payload.size, 321);
+}
+
+TEST_F(SetStatTest, FchmodFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDWR, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  mode_t set_mode = S_IROTH | S_IWOTH | S_IXOTH;
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(set_mode, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(fchmod(fd.get(), set_mode), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_MODE | FATTR_FH);
+  EXPECT_EQ(in_payload.fh, fh);
+  EXPECT_EQ(in_payload.mode, S_IFREG | set_mode);
+}
+
+TEST_F(SetStatTest, FchownFile) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, test_file_mode_);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDWR, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = DefaultFuseAttr(S_IFREG | S_IRUSR | S_IWUSR | S_IXUSR, 2),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SETATTR, iov_out);
+
+  // Make syscall.
+  EXPECT_THAT(fchown(fd.get(), 1025, 1025), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_setattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_SETATTR);
+  EXPECT_EQ(in_header.uid, 0);
+  EXPECT_EQ(in_header.gid, 0);
+  EXPECT_EQ(in_payload.valid, FATTR_UID | FATTR_GID | FATTR_FH);
+  EXPECT_EQ(in_payload.fh, fh);
+  EXPECT_EQ(in_payload.uid, 1025);
+  EXPECT_EQ(in_payload.gid, 1025);
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/stat_test.cc b/test/fuse/linux/stat_test.cc
index 172e09867..6f032cac1 100644
--- a/test/fuse/linux/stat_test.cc
+++ b/test/fuse/linux/stat_test.cc
@@ -18,12 +18,16 @@
 #include <sys/stat.h>
 #include <sys/statfs.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <unistd.h>
 
 #include <vector>
 
 #include "gtest/gtest.h"
-#include "test/fuse/linux/fuse_base.h"
+#include "test/fuse/linux/fuse_fd_util.h"
+#include "test/util/cleanup.h"
+#include "test/util/fs_util.h"
+#include "test/util/fuse_util.h"
 #include "test/util/test_util.h"
 
 namespace gvisor {
@@ -31,89 +35,45 @@ namespace testing {
 
 namespace {
 
-class StatTest : public FuseTest {
+class StatTest : public FuseFdTest {
  public:
-  bool CompareRequest(void* expected_mem, size_t expected_len, void* real_mem,
-                      size_t real_len) override {
-    if (expected_len != real_len) return false;
-    struct fuse_in_header* real_header =
-        reinterpret_cast<fuse_in_header*>(real_mem);
-
-    if (real_header->opcode != FUSE_GETATTR) {
-      std::cerr << "expect header opcode " << FUSE_GETATTR << " but got "
-                << real_header->opcode << std::endl;
-      return false;
-    }
-    return true;
+  void SetUp() override {
+    FuseFdTest::SetUp();
+    test_file_path_ = JoinPath(mount_point_.path(), test_file_);
   }
 
+ protected:
   bool StatsAreEqual(struct stat expected, struct stat actual) {
-    // device number will be dynamically allocated by kernel, we cannot know
-    // in advance
+    // Device number will be dynamically allocated by kernel, we cannot know in
+    // advance.
     actual.st_dev = expected.st_dev;
     return memcmp(&expected, &actual, sizeof(struct stat)) == 0;
   }
+
+  const std::string test_file_ = "testfile";
+  const mode_t expected_mode = S_IFREG | S_IRUSR | S_IWUSR;
+  const uint64_t fh = 23;
+
+  std::string test_file_path_;
 };
 
 TEST_F(StatTest, StatNormal) {
-  struct iovec iov_in[2];
-  struct iovec iov_out[2];
-
-  struct fuse_in_header in_header = {
-      .len = sizeof(struct fuse_in_header) + sizeof(struct fuse_getattr_in),
-      .opcode = FUSE_GETATTR,
-      .unique = 4,
-      .nodeid = 1,
-      .uid = 0,
-      .gid = 0,
-      .pid = 4,
-      .padding = 0,
-  };
-  struct fuse_getattr_in in_payload = {0};
-  iov_in[0].iov_len = sizeof(in_header);
-  iov_in[0].iov_base = &in_header;
-  iov_in[1].iov_len = sizeof(in_payload);
-  iov_in[1].iov_base = &in_payload;
-
-  mode_t expected_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
-  struct timespec atime = {.tv_sec = 1595436289, .tv_nsec = 134150844};
-  struct timespec mtime = {.tv_sec = 1595436290, .tv_nsec = 134150845};
-  struct timespec ctime = {.tv_sec = 1595436291, .tv_nsec = 134150846};
+  // Set up fixture.
+  struct fuse_attr attr = DefaultFuseAttr(expected_mode, 1);
   struct fuse_out_header out_header = {
       .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
-      .error = 0,
-      .unique = 4,
-  };
-  struct fuse_attr attr = {
-      .ino = 1,
-      .size = 512,
-      .blocks = 4,
-      .atime = static_cast<uint64_t>(atime.tv_sec),
-      .mtime = static_cast<uint64_t>(mtime.tv_sec),
-      .ctime = static_cast<uint64_t>(ctime.tv_sec),
-      .atimensec = static_cast<uint32_t>(atime.tv_nsec),
-      .mtimensec = static_cast<uint32_t>(mtime.tv_nsec),
-      .ctimensec = static_cast<uint32_t>(ctime.tv_nsec),
-      .mode = expected_mode,
-      .nlink = 2,
-      .uid = 1234,
-      .gid = 4321,
-      .rdev = 12,
-      .blksize = 4096,
   };
   struct fuse_attr_out out_payload = {
       .attr = attr,
   };
-  iov_out[0].iov_len = sizeof(out_header);
-  iov_out[0].iov_base = &out_header;
-  iov_out[1].iov_len = sizeof(out_payload);
-  iov_out[1].iov_base = &out_payload;
-
-  SetExpected(iov_in, 2, iov_out, 2);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_GETATTR, iov_out);
 
+  // Make syscall.
   struct stat stat_buf;
   EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf), SyscallSucceeds());
 
+  // Check filesystem operation result.
   struct stat expected_stat = {
       .st_ino = attr.ino,
       .st_nlink = attr.nlink,
@@ -124,43 +84,133 @@ TEST_F(StatTest, StatNormal) {
       .st_size = static_cast<off_t>(attr.size),
       .st_blksize = attr.blksize,
       .st_blocks = static_cast<blkcnt_t>(attr.blocks),
-      .st_atim = atime,
-      .st_mtim = mtime,
-      .st_ctim = ctime,
+      .st_atim = (struct timespec){.tv_sec = static_cast<int>(attr.atime),
+                                   .tv_nsec = attr.atimensec},
+      .st_mtim = (struct timespec){.tv_sec = static_cast<int>(attr.mtime),
+                                   .tv_nsec = attr.mtimensec},
+      .st_ctim = (struct timespec){.tv_sec = static_cast<int>(attr.ctime),
+                                   .tv_nsec = attr.ctimensec},
   };
   EXPECT_TRUE(StatsAreEqual(stat_buf, expected_stat));
-  WaitCompleted();
-}
 
-TEST_F(StatTest, StatNotFound) {
-  struct iovec iov_in[2];
-  struct iovec iov_out[2];
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
 
-  struct fuse_in_header in_header = {
-      .len = sizeof(struct fuse_in_header) + sizeof(struct fuse_getattr_in),
-      .opcode = FUSE_GETATTR,
-      .unique = 4,
-  };
-  struct fuse_getattr_in in_payload = {0};
-  iov_in[0].iov_len = sizeof(in_header);
-  iov_in[0].iov_base = &in_header;
-  iov_in[1].iov_len = sizeof(in_payload);
-  iov_in[1].iov_base = &in_payload;
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, 0);
+  EXPECT_EQ(in_payload.fh, 0);
+}
 
+TEST_F(StatTest, StatNotFound) {
+  // Set up fixture.
   struct fuse_out_header out_header = {
       .len = sizeof(struct fuse_out_header),
       .error = -ENOENT,
-      .unique = 4,
   };
-  iov_out[0].iov_len = sizeof(out_header);
-  iov_out[0].iov_base = &out_header;
-
-  SetExpected(iov_in, 2, iov_out, 1);
+  auto iov_out = FuseGenerateIovecs(out_header);
+  SetServerResponse(FUSE_GETATTR, iov_out);
 
+  // Make syscall.
   struct stat stat_buf;
   EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf),
               SyscallFailsWithErrno(ENOENT));
-  WaitCompleted();
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, 0);
+  EXPECT_EQ(in_payload.fh, 0);
+}
+
+TEST_F(StatTest, FstatNormal) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDONLY, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_attr attr = DefaultFuseAttr(expected_mode, 2);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = attr,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_GETATTR, iov_out);
+
+  // Make syscall.
+  struct stat stat_buf;
+  EXPECT_THAT(fstat(fd.get(), &stat_buf), SyscallSucceeds());
+
+  // Check filesystem operation result.
+  struct stat expected_stat = {
+      .st_ino = attr.ino,
+      .st_nlink = attr.nlink,
+      .st_mode = expected_mode,
+      .st_uid = attr.uid,
+      .st_gid = attr.gid,
+      .st_rdev = attr.rdev,
+      .st_size = static_cast<off_t>(attr.size),
+      .st_blksize = attr.blksize,
+      .st_blocks = static_cast<blkcnt_t>(attr.blocks),
+      .st_atim = (struct timespec){.tv_sec = static_cast<int>(attr.atime),
+                                   .tv_nsec = attr.atimensec},
+      .st_mtim = (struct timespec){.tv_sec = static_cast<int>(attr.mtime),
+                                   .tv_nsec = attr.mtimensec},
+      .st_ctim = (struct timespec){.tv_sec = static_cast<int>(attr.ctime),
+                                   .tv_nsec = attr.ctimensec},
+  };
+  EXPECT_TRUE(StatsAreEqual(stat_buf, expected_stat));
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, 0);
+  EXPECT_EQ(in_payload.fh, 0);
+}
+
+TEST_F(StatTest, StatByFileHandle) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, expected_mode, 0);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDONLY, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_attr attr = DefaultFuseAttr(expected_mode, 2, 0);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = attr,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_GETATTR, iov_out);
+
+  // Make syscall.
+  std::vector<char> buf(1);
+  // Since this is an empty file, it won't issue FUSE_READ. But a FUSE_GETATTR
+  // will be issued before read completes.
+  EXPECT_THAT(read(fd.get(), buf.data(), buf.size()), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, FUSE_GETATTR_FH);
+  EXPECT_EQ(in_payload.fh, fh);
 }
 
 }  // namespace
diff --git a/test/fuse/linux/symlink_test.cc b/test/fuse/linux/symlink_test.cc
new file mode 100644
index 000000000..2c3a52987
--- /dev/null
+++ b/test/fuse/linux/symlink_test.cc
@@ -0,0 +1,88 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class SymlinkTest : public FuseTest {
+ protected:
+  const std::string target_file_ = "target_file_";
+  const std::string symlink_ = "symlink_";
+  const mode_t perms_ = S_IRWXU | S_IRWXG | S_IRWXO;
+};
+
+TEST_F(SymlinkTest, CreateSymLink) {
+  const std::string symlink_path =
+      JoinPath(mount_point_.path().c_str(), symlink_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFLNK | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SYMLINK, iov_out);
+  ASSERT_THAT(symlink(target_file_.c_str(), symlink_path.c_str()),
+              SyscallSucceeds());
+
+  struct fuse_in_header in_header;
+  std::vector<char> actual_target_file(target_file_.length() + 1);
+  std::vector<char> actual_symlink(symlink_.length() + 1);
+  auto iov_in =
+      FuseGenerateIovecs(in_header, actual_symlink, actual_target_file);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len,
+            sizeof(in_header) + symlink_.length() + target_file_.length() + 2);
+  EXPECT_EQ(in_header.opcode, FUSE_SYMLINK);
+  EXPECT_EQ(std::string(actual_target_file.data()), target_file_);
+  EXPECT_EQ(std::string(actual_symlink.data()), symlink_);
+}
+
+TEST_F(SymlinkTest, FileTypeError) {
+  const std::string symlink_path =
+      JoinPath(mount_point_.path().c_str(), symlink_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_entry_out),
+  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(S_IFREG | perms_, 5);
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_SYMLINK, iov_out);
+  ASSERT_THAT(symlink(target_file_.c_str(), symlink_path.c_str()),
+              SyscallFailsWithErrno(EIO));
+  SkipServerActualRequest();
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/unlink_test.cc b/test/fuse/linux/unlink_test.cc
new file mode 100644
index 000000000..5702e9b32
--- /dev/null
+++ b/test/fuse/linux/unlink_test.cc
@@ -0,0 +1,83 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class UnlinkTest : public FuseTest {
+ protected:
+  const std::string test_file_ = "test_file";
+};
+
+TEST_F(UnlinkTest, RegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header);
+  SetServerResponse(FUSE_UNLINK, iov_out);
+
+  ASSERT_THAT(unlink(test_file_path.c_str()), SyscallSucceeds());
+  struct fuse_in_header in_header;
+  std::vector<char> unlinked_file(test_file_.length() + 1);
+  auto iov_in = FuseGenerateIovecs(in_header, unlinked_file);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + test_file_.length() + 1);
+  EXPECT_EQ(in_header.opcode, FUSE_UNLINK);
+  EXPECT_EQ(std::string(unlinked_file.data()), test_file_);
+}
+
+TEST_F(UnlinkTest, NoFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header),
+      .error = -ENOENT,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header);
+  SetServerResponse(FUSE_UNLINK, iov_out);
+
+  ASSERT_THAT(unlink(test_file_path.c_str()), SyscallFailsWithErrno(ENOENT));
+  SkipServerActualRequest();
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/fuse/linux/write_test.cc b/test/fuse/linux/write_test.cc
new file mode 100644
index 000000000..1a62beb96
--- /dev/null
+++ b/test/fuse/linux/write_test.cc
@@ -0,0 +1,303 @@
+// Copyright 2020 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class WriteTest : public FuseTest {
+  void SetUp() override {
+    FuseTest::SetUp();
+    test_file_path_ = JoinPath(mount_point_.path().c_str(), test_file_);
+  }
+
+  // TearDown overrides the parent's function
+  // to skip checking the unconsumed release request at the end.
+  void TearDown() override { UnmountFuse(); }
+
+ protected:
+  const std::string test_file_ = "test_file";
+  const mode_t test_file_mode_ = S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO;
+  const uint64_t test_fh_ = 1;
+  const uint32_t open_flag_ = O_RDWR;
+
+  std::string test_file_path_;
+
+  PosixErrorOr<FileDescriptor> OpenTestFile(const std::string &path,
+                                            uint64_t size = 512) {
+    SetServerInodeLookup(test_file_, test_file_mode_, size);
+
+    struct fuse_out_header out_header_open = {
+        .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+    };
+    struct fuse_open_out out_payload_open = {
+        .fh = test_fh_,
+        .open_flags = open_flag_,
+    };
+    auto iov_out_open = FuseGenerateIovecs(out_header_open, out_payload_open);
+    SetServerResponse(FUSE_OPEN, iov_out_open);
+
+    auto res = Open(path.c_str(), open_flag_);
+    if (res.ok()) {
+      SkipServerActualRequest();
+    }
+    return res;
+  }
+};
+
+class WriteTestSmallMaxWrite : public WriteTest {
+  void SetUp() override {
+    MountFuse();
+    SetUpFuseServer(&fuse_init_payload);
+    test_file_path_ = JoinPath(mount_point_.path().c_str(), test_file_);
+  }
+
+ protected:
+  const static uint32_t max_write_ = 4096;
+  constexpr static struct fuse_init_out fuse_init_payload = {
+      .major = 7,
+      .max_write = max_write_,
+  };
+
+  const uint32_t size_fragment = max_write_;
+};
+
+TEST_F(WriteTest, WriteNormal) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the write.
+  const int n_write = 10;
+  struct fuse_out_header out_header_write = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_write_out),
+  };
+  struct fuse_write_out out_payload_write = {
+      .size = n_write,
+  };
+  auto iov_out_write = FuseGenerateIovecs(out_header_write, out_payload_write);
+  SetServerResponse(FUSE_WRITE, iov_out_write);
+
+  // Issue the write.
+  std::vector<char> buf(n_write);
+  RandomizeBuffer(buf.data(), buf.size());
+  EXPECT_THAT(write(fd.get(), buf.data(), n_write),
+              SyscallSucceedsWithValue(n_write));
+
+  // Check the write request.
+  struct fuse_in_header in_header_write;
+  struct fuse_write_in in_payload_write;
+  std::vector<char> payload_buf(n_write);
+  auto iov_in_write =
+      FuseGenerateIovecs(in_header_write, in_payload_write, payload_buf);
+  GetServerActualRequest(iov_in_write);
+
+  EXPECT_EQ(in_payload_write.fh, test_fh_);
+  EXPECT_EQ(in_header_write.len,
+            sizeof(in_header_write) + sizeof(in_payload_write));
+  EXPECT_EQ(in_header_write.opcode, FUSE_WRITE);
+  EXPECT_EQ(in_payload_write.offset, 0);
+  EXPECT_EQ(in_payload_write.size, n_write);
+  EXPECT_EQ(buf, payload_buf);
+}
+
+TEST_F(WriteTest, WriteShort) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the write.
+  const int n_write = 10, n_written = 5;
+  struct fuse_out_header out_header_write = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_write_out),
+  };
+  struct fuse_write_out out_payload_write = {
+      .size = n_written,
+  };
+  auto iov_out_write = FuseGenerateIovecs(out_header_write, out_payload_write);
+  SetServerResponse(FUSE_WRITE, iov_out_write);
+
+  // Issue the write.
+  std::vector<char> buf(n_write);
+  RandomizeBuffer(buf.data(), buf.size());
+  EXPECT_THAT(write(fd.get(), buf.data(), n_write),
+              SyscallSucceedsWithValue(n_written));
+
+  // Check the write request.
+  struct fuse_in_header in_header_write;
+  struct fuse_write_in in_payload_write;
+  std::vector<char> payload_buf(n_write);
+  auto iov_in_write =
+      FuseGenerateIovecs(in_header_write, in_payload_write, payload_buf);
+  GetServerActualRequest(iov_in_write);
+
+  EXPECT_EQ(in_payload_write.fh, test_fh_);
+  EXPECT_EQ(in_header_write.len,
+            sizeof(in_header_write) + sizeof(in_payload_write));
+  EXPECT_EQ(in_header_write.opcode, FUSE_WRITE);
+  EXPECT_EQ(in_payload_write.offset, 0);
+  EXPECT_EQ(in_payload_write.size, n_write);
+  EXPECT_EQ(buf, payload_buf);
+}
+
+TEST_F(WriteTest, WriteShortZero) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Prepare for the write.
+  const int n_write = 10;
+  struct fuse_out_header out_header_write = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_write_out),
+  };
+  struct fuse_write_out out_payload_write = {
+      .size = 0,
+  };
+  auto iov_out_write = FuseGenerateIovecs(out_header_write, out_payload_write);
+  SetServerResponse(FUSE_WRITE, iov_out_write);
+
+  // Issue the write.
+  std::vector<char> buf(n_write);
+  RandomizeBuffer(buf.data(), buf.size());
+  EXPECT_THAT(write(fd.get(), buf.data(), n_write), SyscallFailsWithErrno(EIO));
+
+  // Check the write request.
+  struct fuse_in_header in_header_write;
+  struct fuse_write_in in_payload_write;
+  std::vector<char> payload_buf(n_write);
+  auto iov_in_write =
+      FuseGenerateIovecs(in_header_write, in_payload_write, payload_buf);
+  GetServerActualRequest(iov_in_write);
+
+  EXPECT_EQ(in_payload_write.fh, test_fh_);
+  EXPECT_EQ(in_header_write.len,
+            sizeof(in_header_write) + sizeof(in_payload_write));
+  EXPECT_EQ(in_header_write.opcode, FUSE_WRITE);
+  EXPECT_EQ(in_payload_write.offset, 0);
+  EXPECT_EQ(in_payload_write.size, n_write);
+  EXPECT_EQ(buf, payload_buf);
+}
+
+TEST_F(WriteTest, WriteZero) {
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_));
+
+  // Issue the write.
+  std::vector<char> buf(0);
+  EXPECT_THAT(write(fd.get(), buf.data(), 0), SyscallSucceedsWithValue(0));
+}
+
+TEST_F(WriteTest, PWrite) {
+  const int file_size = 512;
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_, file_size));
+
+  // Prepare for the write.
+  const int n_write = 10;
+  struct fuse_out_header out_header_write = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_write_out),
+  };
+  struct fuse_write_out out_payload_write = {
+      .size = n_write,
+  };
+  auto iov_out_write = FuseGenerateIovecs(out_header_write, out_payload_write);
+  SetServerResponse(FUSE_WRITE, iov_out_write);
+
+  // Issue the write.
+  std::vector<char> buf(n_write);
+  RandomizeBuffer(buf.data(), buf.size());
+  const int offset_write = file_size >> 1;
+  EXPECT_THAT(pwrite(fd.get(), buf.data(), n_write, offset_write),
+              SyscallSucceedsWithValue(n_write));
+
+  // Check the write request.
+  struct fuse_in_header in_header_write;
+  struct fuse_write_in in_payload_write;
+  std::vector<char> payload_buf(n_write);
+  auto iov_in_write =
+      FuseGenerateIovecs(in_header_write, in_payload_write, payload_buf);
+  GetServerActualRequest(iov_in_write);
+
+  EXPECT_EQ(in_payload_write.fh, test_fh_);
+  EXPECT_EQ(in_header_write.len,
+            sizeof(in_header_write) + sizeof(in_payload_write));
+  EXPECT_EQ(in_header_write.opcode, FUSE_WRITE);
+  EXPECT_EQ(in_payload_write.offset, offset_write);
+  EXPECT_EQ(in_payload_write.size, n_write);
+  EXPECT_EQ(buf, payload_buf);
+}
+
+TEST_F(WriteTestSmallMaxWrite, WriteSmallMaxWrie) {
+  const int n_fragment = 10;
+  const int n_write = size_fragment * n_fragment;
+
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenTestFile(test_file_path_, n_write));
+
+  // Prepare for the write.
+  struct fuse_out_header out_header_write = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_write_out),
+  };
+  struct fuse_write_out out_payload_write = {
+      .size = size_fragment,
+  };
+  auto iov_out_write = FuseGenerateIovecs(out_header_write, out_payload_write);
+
+  for (int i = 0; i < n_fragment; ++i) {
+    SetServerResponse(FUSE_WRITE, iov_out_write);
+  }
+
+  // Issue the write.
+  std::vector<char> buf(n_write);
+  RandomizeBuffer(buf.data(), buf.size());
+  EXPECT_THAT(write(fd.get(), buf.data(), n_write),
+              SyscallSucceedsWithValue(n_write));
+
+  ASSERT_EQ(GetServerNumUnsentResponses(), 0);
+  ASSERT_EQ(GetServerNumUnconsumedRequests(), n_fragment);
+
+  // Check the write request.
+  struct fuse_in_header in_header_write;
+  struct fuse_write_in in_payload_write;
+  std::vector<char> payload_buf(size_fragment);
+  auto iov_in_write =
+      FuseGenerateIovecs(in_header_write, in_payload_write, payload_buf);
+
+  for (int i = 0; i < n_fragment; ++i) {
+    GetServerActualRequest(iov_in_write);
+
+    EXPECT_EQ(in_payload_write.fh, test_fh_);
+    EXPECT_EQ(in_header_write.len,
+              sizeof(in_header_write) + sizeof(in_payload_write));
+    EXPECT_EQ(in_header_write.opcode, FUSE_WRITE);
+    EXPECT_EQ(in_payload_write.offset, i * size_fragment);
+    EXPECT_EQ(in_payload_write.size, size_fragment);
+
+    auto it = buf.begin() + i * size_fragment;
+    EXPECT_EQ(std::vector<char>(it, it + size_fragment), payload_buf);
+  }
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/util/BUILD b/test/util/BUILD
index 2a17c33ee..fc5fb3a8d 100644
--- a/test/util/BUILD
+++ b/test/util/BUILD
@@ -46,6 +46,13 @@ cc_library(
 )
 
 cc_library(
+    name = "fuse_util",
+    testonly = 1,
+    srcs = ["fuse_util.cc"],
+    hdrs = ["fuse_util.h"],
+)
+
+cc_library(
     name = "proc_util",
     testonly = 1,
     srcs = ["proc_util.cc"],
diff --git a/test/util/fuse_util.cc b/test/util/fuse_util.cc
new file mode 100644
index 000000000..027f8386c
--- /dev/null
+++ b/test/util/fuse_util.cc
@@ -0,0 +1,63 @@
+// Copyright 2020 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.
+
+#include "test/util/fuse_util.h"
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <string>
+
+namespace gvisor {
+namespace testing {
+
+// Create a default FuseAttr struct with specified mode, inode, and size.
+fuse_attr DefaultFuseAttr(mode_t mode, uint64_t inode, uint64_t size) {
+  const int time_sec = 1595436289;
+  const int time_nsec = 134150844;
+  return (struct fuse_attr){
+      .ino = inode,
+      .size = size,
+      .blocks = 4,
+      .atime = time_sec,
+      .mtime = time_sec,
+      .ctime = time_sec,
+      .atimensec = time_nsec,
+      .mtimensec = time_nsec,
+      .ctimensec = time_nsec,
+      .mode = mode,
+      .nlink = 2,
+      .uid = 1234,
+      .gid = 4321,
+      .rdev = 12,
+      .blksize = 4096,
+  };
+}
+
+// Create response body with specified mode, nodeID, and size.
+fuse_entry_out DefaultEntryOut(mode_t mode, uint64_t node_id, uint64_t size) {
+  struct fuse_entry_out default_entry_out = {
+      .nodeid = node_id,
+      .generation = 0,
+      .entry_valid = 0,
+      .attr_valid = 0,
+      .entry_valid_nsec = 0,
+      .attr_valid_nsec = 0,
+      .attr = DefaultFuseAttr(mode, node_id, size),
+  };
+  return default_entry_out;
+}
+
+}  // namespace testing
+}  // namespace gvisor
diff --git a/test/util/fuse_util.h b/test/util/fuse_util.h
new file mode 100644
index 000000000..544fe1b38
--- /dev/null
+++ b/test/util/fuse_util.h
@@ -0,0 +1,75 @@
+// Copyright 2020 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.
+
+#ifndef GVISOR_TEST_UTIL_FUSE_UTIL_H_
+#define GVISOR_TEST_UTIL_FUSE_UTIL_H_
+
+#include <linux/fuse.h>
+#include <sys/uio.h>
+
+#include <string>
+#include <vector>
+
+namespace gvisor {
+namespace testing {
+
+// The fundamental generation function with a single argument. If passed by
+// std::string or std::vector<char>, it will call specialized versions as
+// implemented below.
+template <typename T>
+std::vector<struct iovec> FuseGenerateIovecs(T &first) {
+  return {(struct iovec){.iov_base = &first, .iov_len = sizeof(first)}};
+}
+
+// If an argument is of type std::string, it must be used in read-only scenario.
+// Because we are setting up iovec, which contains the original address of a
+// data structure, we have to drop const qualification. Usually used with
+// variable-length payload data.
+template <typename T = std::string>
+std::vector<struct iovec> FuseGenerateIovecs(std::string &first) {
+  // Pad one byte for null-terminate c-string.
+  return {(struct iovec){.iov_base = const_cast<char *>(first.c_str()),
+                         .iov_len = first.size() + 1}};
+}
+
+// If an argument is of type std::vector<char>, it must be used in write-only
+// scenario and the size of the variable must be greater than or equal to the
+// size of the expected data. Usually used with variable-length payload data.
+template <typename T = std::vector<char>>
+std::vector<struct iovec> FuseGenerateIovecs(std::vector<char> &first) {
+  return {(struct iovec){.iov_base = first.data(), .iov_len = first.size()}};
+}
+
+// A helper function to set up an array of iovec struct for testing purpose.
+// Use variadic class template to generalize different numbers and different
+// types of FUSE structs.
+template <typename T, typename... Types>
+std::vector<struct iovec> FuseGenerateIovecs(T &first, Types &...args) {
+  auto first_iovec = FuseGenerateIovecs(first);
+  auto iovecs = FuseGenerateIovecs(args...);
+  first_iovec.insert(std::end(first_iovec), std::begin(iovecs),
+                     std::end(iovecs));
+  return first_iovec;
+}
+
+// Create a fuse_attr filled with the specified mode and inode.
+fuse_attr DefaultFuseAttr(mode_t mode, uint64_t inode, uint64_t size = 512);
+
+// Return a fuse_entry_out FUSE server response body.
+fuse_entry_out DefaultEntryOut(mode_t mode, uint64_t node_id,
+                               uint64_t size = 512);
+
+}  // namespace testing
+}  // namespace gvisor
+#endif  // GVISOR_TEST_UTIL_FUSE_UTIL_H_