Add verity_randread benchmark test

PiperOrigin-RevId: 388819374

test/perf/BUILD

@@ -161,6 +161,13 @@ syscall_test(
     vfs1 = False,
 )
 
+syscall_test(
+    size = "large",
+    debug = False,
+    test = "//test/perf/linux:verity_randread_benchmark",
+    vfs1 = False,
+)
+
 syscall_test(
     size = "large",
     debug = False,

test/perf/linux/BUILD

@@ -425,6 +425,25 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "verity_randread_benchmark",
+    testonly = 1,
+    srcs = [
+        "verity_randread_benchmark.cc",
+    ],
+    deps = [
+        gbenchmark,
+        gtest,
+        "//test/util:capability_util",
+        "//test/util:fs_util",
+        "//test/util:logging",
+        "//test/util:temp_path",
+        "//test/util:test_main",
+        "//test/util:test_util",
+        "//test/util:verity_util",
+    ],
+)
+
 cc_binary(
     name = "verity_open_read_close_benchmark",
     testonly = 1,

test/perf/linux/verity_randread_benchmark.cc

@@ -0,0 +1,108 @@
+// Copyright 2021 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 <fcntl.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#include "gtest/gtest.h"
+#include "benchmark/benchmark.h"
+#include "test/util/logging.h"
+#include "test/util/temp_path.h"
+#include "test/util/test_util.h"
+#include "test/util/verity_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+// Create a 1GB file that will be read from at random positions. This should
+// invalid any performance gains from caching.
+const uint64_t kFileSize = Megabytes(1024);
+
+// How many bytes to write at once to initialize the file used to read from.
+const uint32_t kWriteSize = 65536;
+
+// Largest benchmarked read unit.
+const uint32_t kMaxRead = Megabytes(64);
+
+// Global test state, initialized once per process lifetime.
+struct GlobalState {
+  explicit GlobalState() {
+    // Mount a tmpfs file system to be wrapped by a verity fs.
+    tmp_dir_ = TempPath::CreateDir().ValueOrDie();
+    TEST_CHECK(mount("", tmp_dir_.path().c_str(), "tmpfs", 0, "") == 0);
+    file_ = TempPath::CreateFileIn(tmp_dir_.path()).ValueOrDie();
+    filename_ = std::string(Basename(file_.path()));
+
+    FileDescriptor fd = Open(file_.path(), O_WRONLY).ValueOrDie();
+
+    // Try to minimize syscalls by using maximum size writev() requests.
+    std::vector<char> buffer(kWriteSize);
+    RandomizeBuffer(buffer.data(), buffer.size());
+    const std::vector<std::vector<struct iovec>> iovecs_list =
+        GenerateIovecs(kFileSize + kMaxRead, buffer.data(), buffer.size());
+    for (const auto& iovecs : iovecs_list) {
+      TEST_CHECK(writev(fd.get(), iovecs.data(), iovecs.size()) >= 0);
+    }
+    verity_dir_ =
+        MountVerity(tmp_dir_.path(), {EnableTarget(filename_, O_RDONLY)})
+            .ValueOrDie();
+  }
+  TempPath tmp_dir_;
+  TempPath file_;
+  std::string verity_dir_;
+  std::string filename_;
+};
+
+GlobalState& GetGlobalState() {
+  // This gets created only once throughout the lifetime of the process.
+  // Use a dynamically allocated object (that is never deleted) to avoid order
+  // of destruction of static storage variables issues.
+  static GlobalState* const state =
+      // The actual file size is the maximum random seek range (kFileSize) + the
+      // maximum read size so we can read that number of bytes at the end of the
+      // file.
+      new GlobalState();
+  return *state;
+}
+
+void BM_VerityRandRead(benchmark::State& state) {
+  const int size = state.range(0);
+
+  GlobalState& global_state = GetGlobalState();
+  FileDescriptor verity_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(
+      JoinPath(global_state.verity_dir_, global_state.filename_), O_RDONLY));
+  std::vector<char> buf(size);
+
+  unsigned int seed = 1;
+  for (auto _ : state) {
+    TEST_CHECK(PreadFd(verity_fd.get(), buf.data(), buf.size(),
+                       rand_r(&seed) % kFileSize) == size);
+  }
+
+  state.SetBytesProcessed(static_cast<int64_t>(size) *
+                          static_cast<int64_t>(state.iterations()));
+}
+
+BENCHMARK(BM_VerityRandRead)->Range(1, kMaxRead)->UseRealTime();
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor