Implement FUSE_WRITE

This commit adds basic write(2) support for FUSE.

1 files changed, 303 insertions, 0 deletions

diff --git a/test/fuse/linux/write_test.cc b/test/fuse/linux/write_test.cc
new file mode 100644
index 000000000..e7a1aff13
--- /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
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