src/devices/block/drivers/ramdisk/test/ramdisk.cc

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fuchsia/hardware/block/c/fidl.h>
#include <fuchsia/hardware/block/partition/c/fidl.h>
#include <fuchsia/hardware/ramdisk/c/fidl.h>
#include <lib/devmgr-integration-test/fixture.h>
#include <lib/fdio/cpp/caller.h>
#include <lib/fdio/namespace.h>
#include <lib/fdio/watcher.h>
#include <lib/fit/defer.h>
#include <lib/fzl/fifo.h>
#include <lib/fzl/vmo-mapper.h>
#include <lib/sync/completion.h>
#include <lib/zx/channel.h>
#include <lib/zx/fifo.h>
#include <lib/zx/time.h>
#include <lib/zx/vmo.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <threads.h>
#include <time.h>
#include <unistd.h>
#include <zircon/boot/image.h>
#include <zircon/device/block.h>
#include <zircon/syscalls.h>

#include <climits>
#include <limits>
#include <memory>
#include <utility>

#include <block-client/cpp/client.h>
#include <fbl/algorithm.h>
#include <fbl/alloc_checker.h>
#include <fbl/array.h>
#include <fbl/auto_lock.h>
#include <fbl/mutex.h>
#include <fbl/string.h>
#include <fbl/unique_fd.h>
#include <gtest/gtest.h>
#include <ramdevice-client/ramdisk.h>

#include "src/lib/isolated_devmgr/v2_component/bind_devfs_to_namespace.h"

namespace ramdisk {
namespace {

// Make sure isolated_devmgr is ready to go before all tests.
class Environment : public testing::Environment {
 public:
  void SetUp() override {
    ASSERT_EQ(isolated_devmgr::OneTimeSetUp().status_value(), ZX_OK);
    ASSERT_EQ(wait_for_device("/dev/misc/ramctl", ZX_TIME_INFINITE), ZX_OK);
  }
};

testing::Environment* const environment = testing::AddGlobalTestEnvironment(new Environment);

void fill_random(uint8_t* buf, uint64_t size) {
  static unsigned int seed = static_cast<unsigned int>(zx_ticks_get());
  // TODO(fxbug.dev/28197): Make this easier to reproduce with reliably generated prng.
  printf("fill_random of %zu bytes with seed: %u\n", size, seed);
  for (size_t i = 0; i < size; i++) {
    buf[i] = static_cast<uint8_t>(rand_r(&seed));
  }
}

ramdisk_client_t* GetRamdisk(uint64_t blk_size, uint64_t blk_count, const uint8_t* guid = nullptr,
                             size_t guid_len = 0) {
  ramdisk_client_t* ramdisk = nullptr;
  zx_status_t rc = guid ? ramdisk_create_with_guid(blk_size, blk_count, guid, guid_len, &ramdisk)
                        : ramdisk_create(blk_size, blk_count, &ramdisk);
  if (rc != ZX_OK) {
    return nullptr;
  }

  return ramdisk;
}

// Small wrapper around the ramdisk which can be used to ensure the device
// is removed, even if the test fails.
class RamdiskTest {
 public:
  static void Create(uint64_t blk_size, uint64_t blk_count, std::unique_ptr<RamdiskTest>* out) {
    ramdisk_client_t* ramdisk = GetRamdisk(blk_size, blk_count);
    ASSERT_NE(ramdisk, nullptr);
    *out = std::unique_ptr<RamdiskTest>(new RamdiskTest(ramdisk));
  }

  static void CreateWithGuid(uint64_t blk_size, uint64_t blk_count, const uint8_t* guid,
                             size_t guid_len, std::unique_ptr<RamdiskTest>* out) {
    ramdisk_client_t* ramdisk = GetRamdisk(blk_size, blk_count, guid, guid_len);
    ASSERT_NE(ramdisk, nullptr);
    *out = std::unique_ptr<RamdiskTest>(new RamdiskTest(ramdisk));
  }

  void Terminate() {
    if (ramdisk_) {
      ASSERT_EQ(ramdisk_destroy(ramdisk_), ZX_OK);
      ramdisk_ = nullptr;
    }
  }

  ~RamdiskTest() { Terminate(); }

  int block_fd() const { return ramdisk_get_block_fd(ramdisk_); }

  const ramdisk_client_t* ramdisk_client() const { return ramdisk_; }

 private:
  RamdiskTest(ramdisk_client_t* ramdisk) : ramdisk_(ramdisk) {}

  ramdisk_client_t* ramdisk_;
};

TEST(RamdiskTests, RamdiskTestWaitForDevice) {
  EXPECT_EQ(wait_for_device("/", ZX_SEC(1)), ZX_ERR_BAD_PATH);

  char path[PATH_MAX];
  char mod[PATH_MAX];
  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create(512, 64, &ramdisk), ZX_OK);
  strlcpy(path, ramdisk_get_path(ramdisk), sizeof(path));

  // Null path/zero timeout
  EXPECT_EQ(wait_for_device(path, 0), ZX_ERR_INVALID_ARGS);
  EXPECT_EQ(wait_for_device(nullptr, ZX_SEC(1)), ZX_ERR_INVALID_ARGS);

  // Trailing slash:
  // .../ramdisk-xxx/block/
  snprintf(mod, sizeof(mod), "%s/", path);
  EXPECT_EQ(wait_for_device(mod, ZX_SEC(1)), ZX_OK);

  // Repeated slashes/empty path segment:
  // .../ramdisk-xxx//block
  char* sep = strrchr(path, '/');
  ASSERT_NE(sep, nullptr);
  size_t off = sep - path;
  snprintf(&mod[off], sizeof(mod) - off, "/%s", sep);
  EXPECT_EQ(wait_for_device(mod, ZX_SEC(1)), ZX_OK);

  // .../ramdisk-xxx/block
  EXPECT_EQ(wait_for_device(path, ZX_SEC(1)), ZX_OK);
  ASSERT_GE(ramdisk_destroy(ramdisk), 0) << "Could not destroy ramdisk device";
}

TEST(RamdiskTests, RamdiskTestSimple) {
  uint8_t buf[PAGE_SIZE];
  uint8_t out[PAGE_SIZE];

  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE / 2, 512, &ramdisk));
  memset(buf, 'a', sizeof(buf));
  memset(out, 0, sizeof(out));

  // Write a page and a half
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf)), (ssize_t)sizeof(buf));
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf) / 2), (ssize_t)(sizeof(buf) / 2));

  // Seek to the start of the device and read the contents
  ASSERT_EQ(lseek(ramdisk->block_fd(), 0, SEEK_SET), 0);
  ASSERT_EQ(read(ramdisk->block_fd(), out, sizeof(out)), (ssize_t)sizeof(out));
  ASSERT_EQ(memcmp(out, buf, sizeof(out)), 0);
}

TEST(RamdiskTests, RamdiskStatsTest) {
  constexpr size_t kBlockSize = 512;
  constexpr size_t kBlockCount = 512;
  // Set up the initial handshake connection with the ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, kBlockCount, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  groupid_t group = 0;

  // Create an arbitrary VMO, fill it with some stuff
  uint64_t vmo_size = PAGE_SIZE * 3;
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(vmo_size, 0, &vmo), ZX_OK) << "Failed to create VMO";
  std::unique_ptr<uint8_t[]> buf(new uint8_t[vmo_size]);
  fill_random(buf.get(), vmo_size);

  ASSERT_EQ(vmo.write(buf.get(), 0, vmo_size), ZX_OK);

  // Send a handle to the vmo to the block device, get a vmoid which identifies it
  fuchsia_hardware_block_VmoId vmoid;
  zx::vmo xfer_vmo;
  ASSERT_EQ(vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(
      fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status, &vmoid),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  fuchsia_hardware_block_BlockStats block_stats;
  ASSERT_EQ(fuchsia_hardware_block_BlockGetStats(channel->get(), true, &status, &block_stats),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  // Batch write the VMO to the ramdisk
  // Split it into two requests, spread across the disk
  block_fifo_request_t requests[4];
  requests[0].group = group;
  requests[0].vmoid = vmoid.id;
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 1;
  requests[0].vmo_offset = 0;
  requests[0].dev_offset = 0;

  requests[1].group = group;
  requests[1].vmoid = vmoid.id;
  requests[1].opcode = BLOCKIO_READ;
  requests[1].length = 1;
  requests[1].vmo_offset = 1;
  requests[1].dev_offset = 100;

  requests[2].group = group;
  requests[2].vmoid = vmoid.id;
  requests[2].opcode = BLOCKIO_FLUSH;
  requests[2].length = 0;
  requests[2].vmo_offset = 0;
  requests[2].dev_offset = 0;

  requests[3].group = group;
  requests[3].vmoid = vmoid.id;
  requests[3].opcode = BLOCKIO_WRITE;
  requests[3].length = 1;
  requests[3].vmo_offset = 0;
  requests[3].dev_offset = 0;

  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);

  ASSERT_EQ(fuchsia_hardware_block_BlockGetStats(channel->get(), false, &status, &block_stats),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  ASSERT_EQ(block_stats.write.success.total_calls, 2ul);
  ASSERT_EQ(block_stats.write.success.bytes_transferred, 2 * kBlockSize);
  ASSERT_GE(block_stats.read.success.total_calls, 1ul);
  ASSERT_GE(block_stats.read.success.bytes_transferred, 1 * kBlockSize);
  ASSERT_EQ(block_stats.flush.success.total_calls, 1ul);
  ASSERT_EQ(block_stats.flush.success.bytes_transferred, 0ul);

  ASSERT_EQ(block_stats.read.failure.total_calls, 0ul);
  ASSERT_EQ(block_stats.read.failure.bytes_transferred, 0ul);
  ASSERT_EQ(block_stats.write.failure.total_calls, 0ul);
  ASSERT_EQ(block_stats.write.failure.bytes_transferred, 0ul);

  // Close the current vmo
  requests[0].opcode = BLOCKIO_CLOSE_VMO;
  ASSERT_EQ(client.Transaction(&requests[0], 1), ZX_OK);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskGrowTestDimensionsChange) {
  constexpr size_t kBlockCount = 512;
  constexpr size_t kBlockSize = PAGE_SIZE / 2;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, kBlockCount, &ramdisk));

  // Grow the ramdisk.
  ASSERT_EQ(ramdisk_grow(ramdisk->ramdisk_client(), 2 * kBlockSize * kBlockCount), ZX_OK)
      << "Failed to grow ramdisk";

  // Check new block count.
  fuchsia_hardware_block_BlockInfo info;
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx_status_t status;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetInfo(ramdisk_connection.borrow_channel(), &status, &info),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  ASSERT_EQ(info.block_count, 2 * kBlockCount);
  ASSERT_EQ(info.block_size, kBlockSize);
}

TEST(RamdiskTests, RamdiskGrowTestReadFromOldBlocks) {
  uint8_t buf[PAGE_SIZE];
  uint8_t out[PAGE_SIZE];
  constexpr size_t kBlockCount = 512;
  constexpr size_t kBlockSize = PAGE_SIZE / 2;

  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, kBlockCount, &ramdisk));
  memset(buf, 'a', sizeof(buf));
  memset(out, 0, sizeof(out));

  // Write a page and a half
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf)), static_cast<ssize_t>(sizeof(buf)));
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf) / 2),
            static_cast<ssize_t>(sizeof(buf) / 2));

  // Grow the ramdisk.
  ASSERT_EQ(ramdisk_grow(ramdisk->ramdisk_client(), 2 * kBlockSize * kBlockCount), ZX_OK)
      << "Failed to grow ramdisk";

  // Seek to the start of the device and read the contents
  ASSERT_EQ(lseek(ramdisk->block_fd(), 0, SEEK_SET), 0);
  ASSERT_EQ(read(ramdisk->block_fd(), out, sizeof(out)), static_cast<ssize_t>(sizeof(out)));
  ASSERT_EQ(memcmp(out, buf, sizeof(out)), 0);
}

TEST(RamdiskTests, RamdiskGrowTestWriteToAddedBlocks) {
  uint8_t buf[PAGE_SIZE];
  uint8_t out[PAGE_SIZE];
  constexpr size_t kBlockCount = 512;
  constexpr size_t kBlockSize = PAGE_SIZE / 2;

  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, kBlockCount, &ramdisk));
  memset(buf, 'a', sizeof(buf));
  memset(out, 0, sizeof(out));

  // Grow the ramdisk.
  ASSERT_EQ(ramdisk_grow(ramdisk->ramdisk_client(), 2 * kBlockSize * kBlockCount), ZX_OK)
      << "Failed to grow ramdisk";

  // Write a page and a half
  ASSERT_EQ(lseek(ramdisk->block_fd(), kBlockSize * kBlockCount, SEEK_SET),
            off_t{kBlockSize * kBlockCount})
      << strerror(errno);
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf)), static_cast<ssize_t>(sizeof(buf)));
  ASSERT_EQ(write(ramdisk->block_fd(), buf, sizeof(buf) / 2),
            static_cast<ssize_t>(sizeof(buf) / 2));

  // Verify written data is readable from the new blocks.
  ASSERT_EQ(lseek(ramdisk->block_fd(), kBlockCount * kBlockSize, SEEK_SET),
            off_t{kBlockSize * kBlockCount});
  ASSERT_EQ(read(ramdisk->block_fd(), out, sizeof(out)), static_cast<ssize_t>(sizeof(out)));
  ASSERT_EQ(memcmp(out, buf, sizeof(out)), 0);
}

TEST(RamdiskTests, RamdiskTestGuid) {
  constexpr uint8_t kGuid[ZBI_PARTITION_GUID_LEN] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
                                                     0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF};

  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(
      RamdiskTest::CreateWithGuid(PAGE_SIZE / 2, 512, kGuid, sizeof(kGuid), &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  fuchsia_hardware_block_partition_GUID guid;
  ASSERT_EQ(fuchsia_hardware_block_partition_PartitionGetTypeGuid(channel->get(), &status, &guid),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  static_assert(sizeof(guid) == sizeof(kGuid), "Mismatched GUID size");
  ASSERT_TRUE(memcmp(guid.value, kGuid, sizeof(guid)) == 0);
}

TEST(RamdiskTests, RamdiskTestVmo) {
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(256 * PAGE_SIZE, 0, &vmo), ZX_OK);

  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create_from_vmo(vmo.release(), &ramdisk), ZX_OK);
  int block_fd = ramdisk_get_block_fd(ramdisk);

  uint8_t buf[PAGE_SIZE * 2];
  uint8_t out[PAGE_SIZE * 2];
  memset(buf, 'a', sizeof(buf));
  memset(out, 0, sizeof(out));

  EXPECT_EQ(write(block_fd, buf, sizeof(buf)), (ssize_t)sizeof(buf));
  EXPECT_EQ(write(block_fd, buf, sizeof(buf) / 2), (ssize_t)(sizeof(buf) / 2));

  // Seek to the start of the device and read the contents
  EXPECT_EQ(lseek(block_fd, 0, SEEK_SET), 0);
  EXPECT_EQ(read(block_fd, out, sizeof(out)), (ssize_t)sizeof(out));
  EXPECT_EQ(memcmp(out, buf, sizeof(out)), 0);

  EXPECT_GE(ramdisk_destroy(ramdisk), 0) << "Could not unlink ramdisk device";
}

TEST(RamdiskTests, RamdiskTestVmoWithBlockSize) {
  constexpr int kBlockSize = 512;
  constexpr int kBlockCount = 256;
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(kBlockCount * kBlockSize, 0, &vmo), ZX_OK);

  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create_from_vmo_with_block_size(vmo.release(), kBlockSize, &ramdisk), ZX_OK);
  int block_fd = ramdisk_get_block_fd(ramdisk);

  fuchsia_hardware_block_BlockInfo info;
  fdio_cpp::UnownedFdioCaller ramdisk_connection(block_fd);
  zx_status_t status;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetInfo(ramdisk_connection.borrow_channel(), &status, &info),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  ASSERT_EQ(info.block_count, uint64_t{kBlockCount});
  ASSERT_EQ(info.block_size, uint32_t{kBlockSize});

  uint8_t buf[kBlockSize * 2];
  uint8_t out[kBlockSize * 2];
  memset(buf, 'a', sizeof(buf));
  memset(out, 0, sizeof(out));

  EXPECT_EQ(write(block_fd, buf, sizeof(buf)), (ssize_t)sizeof(buf));
  EXPECT_EQ(write(block_fd, buf, sizeof(buf) / 2), (ssize_t)(sizeof(buf) / 2));

  // Seek to the start of the device and read the contents
  EXPECT_EQ(lseek(block_fd, 0, SEEK_SET), 0);
  EXPECT_EQ(read(block_fd, out, sizeof(out)), (ssize_t)sizeof(out));
  EXPECT_EQ(memcmp(out, buf, sizeof(out)), 0);

  EXPECT_GE(ramdisk_destroy(ramdisk), 0) << "Could not unlink ramdisk device";
}

// This test creates a ramdisk, verifies it is visible in the filesystem
// (where we expect it to be!) and verifies that it is removed when we
// "unplug" the device.
TEST(RamdiskTests, RamdiskTestFilesystem) {
  // Make a ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE / 2, 512, &ramdisk));
  char ramdisk_path[PATH_MAX];
  strlcpy(ramdisk_path, ramdisk_get_path(ramdisk->ramdisk_client()), sizeof(ramdisk_path));

  // Ramdisk name is of the form: ".../NAME/block"
  // Extract "NAME".
  const char* name_end = strrchr(ramdisk_path, '/');
  const char* name_start = name_end - 1;
  while (*(name_start - 1) != '/')
    name_start--;
  char name[NAME_MAX];
  memcpy(name, name_start, name_end - name_start);
  name[name_end - name_start] = 0;

  // Verify the ramdisk name
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  size_t actual;
  char out_name[sizeof(name)];
  ASSERT_EQ(fuchsia_hardware_block_partition_PartitionGetName(channel->get(), &status, out_name,
                                                              sizeof(out_name), &actual),
            ZX_OK);
  out_name[actual] = '\0';
  ASSERT_EQ(strnlen(out_name, sizeof(out_name)), strnlen(name, sizeof(name)));
  ASSERT_EQ(strncmp(out_name, name, strnlen(name, sizeof(name))), 0);

  // Find the name of the ramdisk under "/dev/class/block", since it is a block device.
  // Be slightly more lenient with errors during this section, since we might be poking
  // block devices that don't belong to us.
  char blockpath[PATH_MAX];
  strcpy(blockpath, "/dev/class/block/");
  DIR* dir = opendir(blockpath);
  ASSERT_NE(dir, nullptr);
  const auto closer = fit::defer([dir]() { closedir(dir); });

  typedef struct watcher_args {
    const char* expected_name;
    char* blockpath;
    fbl::String filename;
    bool found;
  } watcher_args_t;

  watcher_args_t args;
  args.expected_name = name;
  args.blockpath = blockpath;
  args.found = false;

  auto cb = [](int dirfd, int event, const char* fn, void* cookie) {
    watcher_args_t* args = static_cast<watcher_args_t*>(cookie);
    if (event == WATCH_EVENT_ADD_FILE) {
      fbl::unique_fd fd(openat(dirfd, fn, O_RDONLY));
      if (!fd) {
        return ZX_OK;
      }

      fdio_cpp::FdioCaller ramdisk_connection(std::move(fd));
      zx::unowned_channel channel(ramdisk_connection.borrow_channel());
      zx_status_t io_status, status;
      size_t actual;
      char out_name[sizeof(name)];
      io_status = fuchsia_hardware_block_partition_PartitionGetName(
          channel->get(), &status, out_name, sizeof(out_name), &actual);
      if (io_status == ZX_OK && status == ZX_OK && actual == strlen(args->expected_name) &&
          strncmp(out_name, args->expected_name, strlen(args->expected_name)) == 0) {
        // Found a device under /dev/class/block/XYZ with the name of the
        // ramdisk we originally created.
        strncat(args->blockpath, fn, sizeof(blockpath) - (strlen(args->blockpath) + 1));
        args->filename = fbl::String(fn);
        args->found = true;
        return ZX_ERR_STOP;
      }
    }
    return ZX_OK;
  };

  zx_time_t deadline = zx_deadline_after(ZX_SEC(3));
  ASSERT_EQ(fdio_watch_directory(dirfd(dir), cb, deadline, &args), ZX_ERR_STOP);
  ASSERT_TRUE(args.found);

  // Check dev block is accessible before destruction
  int devfd = open(blockpath, O_RDONLY);
  ASSERT_GE(devfd, 0) << "Ramdisk is not visible in /dev/class/block";
  ASSERT_EQ(close(devfd), 0);

  // Start watching for the block device removal.
  std::unique_ptr<devmgr_integration_test::DirWatcher> watcher;
  ASSERT_EQ(devmgr_integration_test::DirWatcher::Create(fbl::unique_fd(dirfd(dir)), &watcher),
            ZX_OK);

  ASSERT_NO_FATAL_FAILURE(ramdisk->Terminate());

  ASSERT_EQ(watcher->WaitForRemoval(args.filename, zx::sec(5)), ZX_OK);

  // Now that we've unlinked the ramdisk, we should notice that it doesn't appear
  // under /dev/class/block.
  ASSERT_EQ(open(blockpath, O_RDONLY), -1) << "Ramdisk is visible in /dev after destruction";
}

TEST(RamdiskTests, RamdiskTestRebind) {
  // Make a ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE / 2, 512, &ramdisk));

  // Rebind the ramdisk driver
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;

  ASSERT_EQ(fuchsia_hardware_block_BlockRebindDevice(channel->get(), &status), ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  ASSERT_EQ(wait_for_device(ramdisk_get_path(ramdisk->ramdisk_client()), ZX_SEC(3)), ZX_OK);
}

TEST(RamdiskTests, RamdiskTestBadRequests) {
  uint8_t buf[PAGE_SIZE];

  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk));
  memset(buf, 'a', sizeof(buf));

  // Read / write non-multiples of the block size
  ASSERT_EQ(write(ramdisk->block_fd(), buf, PAGE_SIZE - 1), -1);
  ASSERT_EQ(errno, EINVAL);
  ASSERT_EQ(write(ramdisk->block_fd(), buf, PAGE_SIZE / 2), -1);
  ASSERT_EQ(errno, EINVAL);
  ASSERT_EQ(read(ramdisk->block_fd(), buf, PAGE_SIZE - 1), -1);
  ASSERT_EQ(errno, EINVAL);
  ASSERT_EQ(read(ramdisk->block_fd(), buf, PAGE_SIZE / 2), -1);
  ASSERT_EQ(errno, EINVAL);

  // Read / write from unaligned offset
  ASSERT_EQ(lseek(ramdisk->block_fd(), 1, SEEK_SET), 1);
  ASSERT_EQ(write(ramdisk->block_fd(), buf, PAGE_SIZE), -1);
  ASSERT_EQ(errno, EINVAL);
  ASSERT_EQ(read(ramdisk->block_fd(), buf, PAGE_SIZE), -1);
  ASSERT_EQ(errno, EINVAL);

  // Read / write at end of device
  off_t offset = PAGE_SIZE * 512;
  ASSERT_EQ(lseek(ramdisk->block_fd(), offset, SEEK_SET), offset);
  ASSERT_EQ(write(ramdisk->block_fd(), buf, PAGE_SIZE), -1);
  ASSERT_EQ(read(ramdisk->block_fd(), buf, PAGE_SIZE), -1);
}

TEST(RamdiskTests, RamdiskTestReleaseDuringAccess) {
  ramdisk_client_t* ramdisk = GetRamdisk(PAGE_SIZE, 512);
  ASSERT_NE(ramdisk, nullptr);

  // Spin up a background thread to repeatedly access
  // the first few blocks.
  auto bg_thread = [](void* arg) {
    int fd = *reinterpret_cast<int*>(arg);
    while (true) {
      uint8_t in[8192];
      memset(in, 'a', sizeof(in));
      if (write(fd, in, sizeof(in)) != static_cast<ssize_t>(sizeof(in))) {
        return 0;
      }
      uint8_t out[8192];
      memset(out, 0, sizeof(out));
      lseek(fd, 0, SEEK_SET);
      if (read(fd, out, sizeof(out)) != static_cast<ssize_t>(sizeof(out))) {
        return 0;
      }
      // If we DID manage to read it, then the data should be valid...
      if (memcmp(in, out, sizeof(in)) != 0) {
        return -1;
      }
    }
  };

  thrd_t thread;
  int raw_fd = ramdisk_get_block_fd(ramdisk);
  ASSERT_EQ(thrd_create(&thread, bg_thread, &raw_fd), thrd_success);
  // Let the background thread warm up a little bit...
  usleep(10000);
  // ... and close the entire ramdisk from undearneath it!
  ASSERT_EQ(ramdisk_destroy(ramdisk), ZX_OK);

  int res;
  ASSERT_EQ(thrd_join(thread, &res), thrd_success);
  ASSERT_EQ(res, 0) << "Background thread failed";
}

TEST(RamdiskTests, RamdiskTestMultiple) {
  uint8_t buf[PAGE_SIZE];
  uint8_t out[PAGE_SIZE];

  std::unique_ptr<RamdiskTest> ramdisk1;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk1));
  std::unique_ptr<RamdiskTest> ramdisk2;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk2));

  // Write 'a' to fd1, write 'b', to fd2
  memset(buf, 'a', sizeof(buf));
  ASSERT_EQ(write(ramdisk1->block_fd(), buf, sizeof(buf)), (ssize_t)sizeof(buf));
  memset(buf, 'b', sizeof(buf));
  ASSERT_EQ(write(ramdisk2->block_fd(), buf, sizeof(buf)), (ssize_t)sizeof(buf));

  ASSERT_EQ(lseek(ramdisk1->block_fd(), 0, SEEK_SET), 0);
  ASSERT_EQ(lseek(ramdisk2->block_fd(), 0, SEEK_SET), 0);

  // Read 'b' from fd2, read 'a' from fd1
  ASSERT_EQ(read(ramdisk2->block_fd(), out, sizeof(buf)), (ssize_t)sizeof(buf));
  ASSERT_EQ(memcmp(out, buf, sizeof(out)), 0);
  ASSERT_NO_FATAL_FAILURE(ramdisk2->Terminate()) << "Could not unlink ramdisk device";

  memset(buf, 'a', sizeof(buf));
  ASSERT_EQ(read(ramdisk1->block_fd(), out, sizeof(buf)), (ssize_t)sizeof(buf));
  ASSERT_EQ(memcmp(out, buf, sizeof(out)), 0);
  ASSERT_NO_FATAL_FAILURE(ramdisk1->Terminate()) << "Could not unlink ramdisk device";
}

TEST(RamdiskTests, RamdiskTestFifoNoOp) {
  // Get a FIFO connection to a ramdisk and immediately close it
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE / 2, 512, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());

  auto open_and_close_fifo = [&channel]() {
    zx_status_t status;
    zx::fifo fifo;
    ASSERT_EQ(
        fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
        ZX_OK);
    ASSERT_EQ(status, ZX_OK);
    ASSERT_EQ(fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status), ZX_OK);
    ASSERT_EQ(status, ZX_OK);
  };

  ASSERT_NO_FATAL_FAILURE(open_and_close_fifo());
  ASSERT_NO_FATAL_FAILURE(open_and_close_fifo());

  ASSERT_NO_FATAL_FAILURE(ramdisk->Terminate()) << "Could not unlink ramdisk device";
}

TEST(RamdiskTests, RamdiskTestFifoBasic) {
  // Set up the initial handshake connection with the ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  groupid_t group = 0;

  // Create an arbitrary VMO, fill it with some stuff
  uint64_t vmo_size = PAGE_SIZE * 3;
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(vmo_size, 0, &vmo), ZX_OK) << "Failed to create VMO";
  std::unique_ptr<uint8_t[]> buf(new uint8_t[vmo_size]);
  fill_random(buf.get(), vmo_size);

  ASSERT_EQ(vmo.write(buf.get(), 0, vmo_size), ZX_OK);

  // Send a handle to the vmo to the block device, get a vmoid which identifies it
  fuchsia_hardware_block_VmoId vmoid;
  zx::vmo xfer_vmo;
  ASSERT_EQ(vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(
      fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status, &vmoid),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);

  // Batch write the VMO to the ramdisk
  // Split it into two requests, spread across the disk
  block_fifo_request_t requests[2];
  requests[0].group = group;
  requests[0].vmoid = vmoid.id;
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 1;
  requests[0].vmo_offset = 0;
  requests[0].dev_offset = 0;

  requests[1].group = group;
  requests[1].vmoid = vmoid.id;
  requests[1].opcode = BLOCKIO_WRITE;
  requests[1].length = 2;
  requests[1].vmo_offset = 1;
  requests[1].dev_offset = 100;

  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);

  // Empty the vmo, then read the info we just wrote to the disk
  std::unique_ptr<uint8_t[]> out(new uint8_t[vmo_size]());

  ASSERT_EQ(vmo.write(out.get(), 0, vmo_size), ZX_OK);
  requests[0].opcode = BLOCKIO_READ;
  requests[1].opcode = BLOCKIO_READ;
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);
  ASSERT_EQ(vmo.read(out.get(), 0, vmo_size), ZX_OK);
  ASSERT_EQ(memcmp(buf.get(), out.get(), vmo_size), 0) << "Read data not equal to written data";

  // Close the current vmo
  requests[0].opcode = BLOCKIO_CLOSE_VMO;
  ASSERT_EQ(client.Transaction(&requests[0], 1), ZX_OK);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoNoGroup) {
  // Set up the initial handshake connection with the ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo raw_fifo;
  ASSERT_EQ(fuchsia_hardware_block_BlockGetFifo(channel->get(), &status,
                                                raw_fifo.reset_and_get_address()),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  fzl::fifo<block_fifo_request_t, block_fifo_response_t> fifo(std::move(raw_fifo));

  // Create an arbitrary VMO, fill it with some stuff
  uint64_t vmo_size = PAGE_SIZE * 3;
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(vmo_size, 0, &vmo), ZX_OK) << "Failed to create VMO";
  std::unique_ptr<uint8_t[]> buf(new uint8_t[vmo_size]);
  fill_random(buf.get(), vmo_size);

  ASSERT_EQ(vmo.write(buf.get(), 0, vmo_size), ZX_OK);

  // Send a handle to the vmo to the block device, get a vmoid which identifies it
  fuchsia_hardware_block_VmoId vmoid;
  zx::vmo xfer_vmo;
  ASSERT_EQ(vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(
      fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status, &vmoid),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  // Batch write the VMO to the ramdisk
  // Split it into two requests, spread across the disk
  block_fifo_request_t requests[2];
  requests[0].reqid = 0;
  requests[0].vmoid = vmoid.id;
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 1;
  requests[0].vmo_offset = 0;
  requests[0].dev_offset = 0;

  requests[1].reqid = 1;
  requests[1].vmoid = vmoid.id;
  requests[1].opcode = BLOCKIO_WRITE;
  requests[1].length = 2;
  requests[1].vmo_offset = 1;
  requests[1].dev_offset = 100;

  auto write_request = [&fifo](block_fifo_request_t* request) {
    size_t actual;
    ASSERT_EQ(fifo.write(request, 1, &actual), ZX_OK);
    ASSERT_EQ(actual, 1ul);
  };

  auto read_response = [&fifo](reqid_t reqid) {
    zx::time deadline = zx::deadline_after(zx::sec(1));
    block_fifo_response_t response;
    ASSERT_EQ(fifo.wait_one(ZX_FIFO_READABLE, deadline, nullptr), ZX_OK);
    ASSERT_EQ(fifo.read(&response, 1, nullptr), ZX_OK);
    ASSERT_EQ(response.status, ZX_OK);
    ASSERT_EQ(response.reqid, reqid);
  };

  ASSERT_NO_FATAL_FAILURE(write_request(&requests[0]));
  ASSERT_NO_FATAL_FAILURE(read_response(0));
  ASSERT_NO_FATAL_FAILURE(write_request(&requests[1]));
  ASSERT_NO_FATAL_FAILURE(read_response(1));

  // Empty the vmo, then read the info we just wrote to the disk
  std::unique_ptr<uint8_t[]> out(new uint8_t[vmo_size]());

  ASSERT_EQ(vmo.write(out.get(), 0, vmo_size), ZX_OK);

  requests[0].opcode = BLOCKIO_READ;
  requests[1].opcode = BLOCKIO_READ;

  ASSERT_NO_FATAL_FAILURE(write_request(&requests[0]));
  ASSERT_NO_FATAL_FAILURE(read_response(0));
  ASSERT_NO_FATAL_FAILURE(write_request(&requests[1]));
  ASSERT_NO_FATAL_FAILURE(read_response(1));

  ASSERT_EQ(vmo.read(out.get(), 0, vmo_size), ZX_OK);
  ASSERT_EQ(memcmp(buf.get(), out.get(), vmo_size), 0) << "Read data not equal to written data";

  // Close the current vmo
  requests[0].opcode = BLOCKIO_CLOSE_VMO;
  ASSERT_EQ(fifo.write(requests, 1, nullptr), ZX_OK);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

typedef struct {
  uint64_t vmo_size;
  zx::vmo vmo;
  fuchsia_hardware_block_VmoId vmoid;
  std::unique_ptr<uint8_t[]> buf;
} TestVmoObject;

// Creates a VMO, fills it with data, and gives it to the block device.
//
// TODO(smklein): Operate directly on ramdisk_connection, rather than fd.
void create_vmo_helper(int fd, TestVmoObject* obj, size_t kBlockSize) {
  obj->vmo_size = kBlockSize + (rand() % 5) * kBlockSize;
  ASSERT_EQ(zx::vmo::create(obj->vmo_size, 0, &obj->vmo), ZX_OK) << "Failed to create vmo";
  obj->buf.reset(new uint8_t[obj->vmo_size]);
  fill_random(obj->buf.get(), obj->vmo_size);
  ASSERT_EQ(obj->vmo.write(obj->buf.get(), 0, obj->vmo_size), ZX_OK) << "Failed to write to vmo";

  fdio_cpp::UnownedFdioCaller ramdisk_connection(fd);
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::vmo xfer_vmo;
  ASSERT_EQ(obj->vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status,
                                                  &obj->vmoid),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);
}

// Write all vmos in a striped pattern on disk.
// For objs.size() == 10,
// i = 0 will write vmo block 0, 1, 2, 3... to dev block 0, 10, 20, 30...
// i = 1 will write vmo block 0, 1, 2, 3... to dev block 1, 11, 21, 31...
void write_striped_vmo_helper(const block_client::Client* client, TestVmoObject* obj, size_t i,
                              size_t objs, groupid_t group, size_t kBlockSize) {
  // Make a separate request for each block
  size_t blocks = obj->vmo_size / kBlockSize;
  fbl::Array<block_fifo_request_t> requests(new block_fifo_request_t[blocks], blocks);
  for (size_t b = 0; b < blocks; b++) {
    requests[b].group = group;
    requests[b].vmoid = obj->vmoid.id;
    requests[b].opcode = BLOCKIO_WRITE;
    requests[b].length = 1;
    requests[b].vmo_offset = b;
    requests[b].dev_offset = i + b * objs;
  }
  // Write entire vmos at once
  ASSERT_EQ(client->Transaction(&requests[0], requests.size()), ZX_OK);
}

// Verifies the result from "write_striped_vmo_helper"
void read_striped_vmo_helper(const block_client::Client* client, TestVmoObject* obj, size_t i,
                             size_t objs, groupid_t group, size_t kBlockSize) {
  // First, empty out the VMO
  std::unique_ptr<uint8_t[]> out(new uint8_t[obj->vmo_size]());
  ASSERT_EQ(obj->vmo.write(out.get(), 0, obj->vmo_size), ZX_OK);

  // Next, read to the vmo from the disk
  size_t blocks = obj->vmo_size / kBlockSize;
  fbl::Array<block_fifo_request_t> requests(new block_fifo_request_t[blocks], blocks);
  for (size_t b = 0; b < blocks; b++) {
    requests[b].group = group;
    requests[b].vmoid = obj->vmoid.id;
    requests[b].opcode = BLOCKIO_READ;
    requests[b].length = 1;
    requests[b].vmo_offset = b;
    requests[b].dev_offset = i + b * objs;
  }
  // Read entire vmos at once
  ASSERT_EQ(client->Transaction(&requests[0], requests.size()), ZX_OK);

  // Finally, write from the vmo to an out buffer, where we can compare
  // the results with the input buffer.
  ASSERT_EQ(obj->vmo.read(out.get(), 0, obj->vmo_size), ZX_OK);
  ASSERT_EQ(memcmp(obj->buf.get(), out.get(), obj->vmo_size), 0)
      << "Read data not equal to written data";
}

// Tears down an object created by "create_vmo_helper".
void close_vmo_helper(const block_client::Client* client, TestVmoObject* obj, groupid_t group) {
  block_fifo_request_t request;
  request.group = group;
  request.vmoid = obj->vmoid.id;
  request.opcode = BLOCKIO_CLOSE_VMO;
  ASSERT_EQ(client->Transaction(&request, 1), ZX_OK);
}

TEST(RamdiskTests, RamdiskTestFifoMultipleVmo) {
  // Set up the initial handshake connection with the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  groupid_t group = 0;
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);

  // Create multiple VMOs
  fbl::Array<TestVmoObject> objs(new TestVmoObject[10](), 10);
  for (size_t i = 0; i < objs.size(); i++) {
    ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &objs[i], kBlockSize));
  }

  for (size_t i = 0; i < objs.size(); i++) {
    ASSERT_NO_FATAL_FAILURE(
        write_striped_vmo_helper(&client, &objs[i], i, objs.size(), group, kBlockSize));
  }

  for (size_t i = 0; i < objs.size(); i++) {
    ASSERT_NO_FATAL_FAILURE(
        read_striped_vmo_helper(&client, &objs[i], i, objs.size(), group, kBlockSize));
  }

  for (size_t i = 0; i < objs.size(); i++) {
    ASSERT_NO_FATAL_FAILURE(close_vmo_helper(&client, &objs[i], group));
  }
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

typedef struct {
  TestVmoObject* obj;
  size_t i;
  size_t objs;
  int fd;
  const block_client::Client* client;
  groupid_t group;
  size_t kBlockSize;
} TestThreadArg;

void fifo_vmo_thread(TestThreadArg* fifoarg) {
  TestVmoObject* obj = fifoarg->obj;
  size_t i = fifoarg->i;
  size_t objs = fifoarg->objs;
  int fd = fifoarg->fd;
  const block_client::Client* client = fifoarg->client;
  groupid_t group = fifoarg->group;
  size_t kBlockSize = fifoarg->kBlockSize;

  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(fd, obj, kBlockSize));
  ASSERT_NO_FATAL_FAILURE(write_striped_vmo_helper(client, obj, i, objs, group, kBlockSize));
  ASSERT_NO_FATAL_FAILURE(read_striped_vmo_helper(client, obj, i, objs, group, kBlockSize));
  ASSERT_NO_FATAL_FAILURE(close_vmo_helper(client, obj, group));
}

int fifo_vmo_thread_wrapper(void* arg) {
  fifo_vmo_thread(reinterpret_cast<TestThreadArg*>(arg));
  return 0;
}

TEST(RamdiskTests, RamdiskTestFifoMultipleVmoMultithreaded) {
  // Set up the initial handshake connection with the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);

  // Create multiple VMOs
  size_t num_threads = MAX_TXN_GROUP_COUNT;
  fbl::Array<TestVmoObject> objs(new TestVmoObject[num_threads](), num_threads);
  fbl::Array<thrd_t> threads(new thrd_t[num_threads](), num_threads);
  fbl::Array<TestThreadArg> thread_args(new TestThreadArg[num_threads](), num_threads);

  for (size_t i = 0; i < num_threads; i++) {
    // Yes, this does create a bunch of duplicate fields, but it's an easy way to
    // transfer some data without creating global variables.
    thread_args[i].obj = &objs[i];
    thread_args[i].i = i;
    thread_args[i].objs = objs.size();
    thread_args[i].fd = ramdisk->block_fd();
    thread_args[i].client = &client;
    thread_args[i].group = static_cast<groupid_t>(i);
    thread_args[i].kBlockSize = kBlockSize;
    ASSERT_EQ(thrd_create(&threads[i], fifo_vmo_thread_wrapper, &thread_args[i]), thrd_success);
  }

  for (size_t i = 0; i < num_threads; i++) {
    int res;
    ASSERT_EQ(thrd_join(threads[i], &res), thrd_success);
    ASSERT_EQ(res, 0);
  }
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

// TODO(smklein): Test ops across different vmos
TEST(RamdiskTests, RamdiskTestFifoLargeOpsCount) {
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);

  // Create a vmo
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBlockSize));

  for (size_t num_ops = 1; num_ops <= 32; num_ops++) {
    groupid_t group = 0;

    fbl::Array<block_fifo_request_t> requests(new block_fifo_request_t[num_ops](), num_ops);

    for (size_t b = 0; b < num_ops; b++) {
      requests[b].group = group;
      requests[b].vmoid = obj.vmoid.id;
      requests[b].opcode = BLOCKIO_WRITE;
      requests[b].length = 1;
      requests[b].vmo_offset = 0;
      requests[b].dev_offset = 0;
    }

    ASSERT_EQ(client.Transaction(&requests[0], requests.size()), ZX_OK);
  }
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoLargeOpsCountShutdown) {
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  // Create a vmo
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBlockSize));

  const size_t kNumOps = BLOCK_FIFO_MAX_DEPTH;
  groupid_t group = 0;

  fbl::Array<block_fifo_request_t> requests(new block_fifo_request_t[kNumOps](), kNumOps);

  for (size_t b = 0; b < kNumOps; b++) {
    requests[b].group = group;
    requests[b].vmoid = obj.vmoid.id;
    requests[b].opcode = BLOCKIO_WRITE | BLOCKIO_GROUP_ITEM;
    requests[b].length = 1;
    requests[b].vmo_offset = 0;
    requests[b].dev_offset = b;
  }

  // Enqueue multiple barrier-based operations without waiting
  // for completion. The intention here is for the block device
  // server to be busy processing multiple pending operations
  // when the FIFO is suddenly closed, causing "server termination
  // with pending work".
  //
  // It's obviously hit-or-miss whether the server will actually
  // be processing work when we shut down the fifo, but run in a
  // loop, this test was able to trigger deadlocks in a buggy
  // version of the server; as a consequence, it is preserved
  // to help detect regressions.
  size_t actual;
  ZX_ASSERT(fifo.write(sizeof(block_fifo_request_t), &requests[0], requests.size(), &actual) ==
            ZX_OK);
  usleep(100);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
  fifo.reset();
}

TEST(RamdiskTests, RamdiskTestFifoIntermediateOpFailure) {
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  groupid_t group = 0;

  constexpr size_t kRequestCount = 3;
  constexpr size_t kBufferSize = kRequestCount * kBlockSize;

  // Create a vmo
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBufferSize));

  // Store the original value of the VMO
  std::unique_ptr<uint8_t[]> originalbuf;
  originalbuf.reset(new uint8_t[kBufferSize]);

  ASSERT_EQ(obj.vmo.read(originalbuf.get(), 0, kBufferSize), ZX_OK);

  // Test that we can use regular transactions (writing)
  block_fifo_request_t requests[kRequestCount];
  for (size_t i = 0; i < std::size(requests); i++) {
    requests[i].group = group;
    requests[i].vmoid = obj.vmoid.id;
    requests[i].opcode = BLOCKIO_WRITE;
    requests[i].length = 1;
    requests[i].vmo_offset = i;
    requests[i].dev_offset = i;
  }
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);

  std::unique_ptr<uint8_t[]> tmpbuf;
  tmpbuf.reset(new uint8_t[kBufferSize]);

  for (size_t bad_arg = 0; bad_arg < std::size(requests); bad_arg++) {
    // Empty out the VMO so we can test reading it
    memset(tmpbuf.get(), 0, kBufferSize);
    ASSERT_EQ(obj.vmo.write(tmpbuf.get(), 0, kBufferSize), ZX_OK);

    // Test that invalid intermediate operations cause:
    // - Previous operations to continue anyway
    // - Later operations to fail
    for (size_t i = 0; i < std::size(requests); i++) {
      requests[i].group = group;
      requests[i].vmoid = obj.vmoid.id;
      requests[i].opcode = BLOCKIO_READ;
      requests[i].length = 1;
      requests[i].vmo_offset = i;
      requests[i].dev_offset = i;
    }
    // Inserting "bad argument".
    requests[bad_arg].length = 0;
    ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_ERR_INVALID_ARGS);

    // Test that all operations up the bad argument completed, but the later
    // ones did not.
    ASSERT_EQ(obj.vmo.read(tmpbuf.get(), 0, kBufferSize), ZX_OK);

    // First few (successful) operations
    ASSERT_EQ(memcmp(tmpbuf.get(), originalbuf.get(), kBlockSize * bad_arg), 0);
    // Later (failed) operations
    for (size_t i = kBlockSize * (bad_arg + 1); i < kBufferSize; i++) {
      ASSERT_EQ(tmpbuf[i], 0);
    }
  }
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoBadClientVmoid) {
  // Try to flex the server's error handling by sending 'malicious' client requests.
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  groupid_t group = 0;

  // Create a vmo
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBlockSize));

  // Bad request: Writing to the wrong vmoid
  block_fifo_request_t request;
  request.group = group;
  request.vmoid = static_cast<vmoid_t>(obj.vmoid.id + 5);
  request.opcode = BLOCKIO_WRITE;
  request.length = 1;
  request.vmo_offset = 0;
  request.dev_offset = 0;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_IO) << "Expected IO error with bad vmoid";
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoBadClientUnalignedRequest) {
  // Try to flex the server's error handling by sending 'malicious' client requests.
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  groupid_t group = 0;

  // Create a vmo of at least size "kBlockSize * 2", since we'll
  // be reading "kBlockSize" bytes from an offset below, and we want it
  // to fit within the bounds of the VMO.
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBlockSize * 2));

  block_fifo_request_t request;
  request.group = group;
  request.vmoid = static_cast<vmoid_t>(obj.vmoid.id);
  request.opcode = BLOCKIO_WRITE;

  // Send a request that has zero length
  request.length = 0;
  request.vmo_offset = 0;
  request.dev_offset = 0;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_INVALID_ARGS);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoBadClientOverflow) {
  // Try to flex the server's error handling by sending 'malicious' client requests.
  // Set up the ramdisk
  const uint64_t kBlockSize = PAGE_SIZE;
  const uint64_t kBlockCount = 1 << 18;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, kBlockCount, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  groupid_t group = 0;

  // Create a vmo of at least size "kBlockSize * 2", since we'll
  // be reading "kBlockSize" bytes from an offset below, and we want it
  // to fit within the bounds of the VMO.
  TestVmoObject obj;
  ASSERT_NO_FATAL_FAILURE(create_vmo_helper(ramdisk->block_fd(), &obj, kBlockSize * 2));

  block_fifo_request_t request;
  request.group = group;
  request.vmoid = static_cast<vmoid_t>(obj.vmoid.id);
  request.opcode = BLOCKIO_WRITE;

  // Send a request that is barely out-of-bounds for the device
  request.length = 1;
  request.vmo_offset = 0;
  request.dev_offset = kBlockCount;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);

  // Send a request that is half out-of-bounds for the device
  request.length = 2;
  request.vmo_offset = 0;
  request.dev_offset = kBlockCount - 1;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);

  // Send a request that is very out-of-bounds for the device
  request.length = 1;
  request.vmo_offset = 0;
  request.dev_offset = kBlockCount + 1;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);

  // Send a request that tries to overflow the VMO
  request.length = 2;
  request.vmo_offset = std::numeric_limits<uint64_t>::max();
  request.dev_offset = 0;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);

  // Send a request that tries to overflow the device
  request.length = 2;
  request.vmo_offset = 0;
  request.dev_offset = std::numeric_limits<uint64_t>::max();
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoBadClientBadVmo) {
  // Try to flex the server's error handling by sending 'malicious' client requests.
  // Set up the ramdisk
  const size_t kBlockSize = PAGE_SIZE;
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(kBlockSize, 1 << 18, &ramdisk));

  // Create a connection to the ramdisk
  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);
  groupid_t group = 0;

  // create a VMO of 1 block, which will round up to PAGE_SIZE
  TestVmoObject obj;
  obj.vmo_size = kBlockSize;
  ASSERT_EQ(zx::vmo::create(obj.vmo_size, 0, &obj.vmo), ZX_OK) << "Failed to create vmo";
  obj.buf.reset(new uint8_t[obj.vmo_size]);
  fill_random(obj.buf.get(), obj.vmo_size);
  ASSERT_EQ(obj.vmo.write(obj.buf.get(), 0, obj.vmo_size), ZX_OK) << "Failed to write to vmo";

  zx::vmo xfer_vmo;
  ASSERT_EQ(obj.vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status,
                                                  &obj.vmoid),
            ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  // Send a request to write to write 2 blocks -- even though that's larger than the VMO
  block_fifo_request_t request;
  request.group = group;
  request.vmoid = static_cast<vmoid_t>(obj.vmoid.id);
  request.opcode = BLOCKIO_WRITE;
  request.length = 2;
  request.vmo_offset = 0;
  request.dev_offset = 0;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);
  // Do the same thing, but for reading
  request.opcode = BLOCKIO_READ;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);
  request.length = 2;
  ASSERT_EQ(client.Transaction(&request, 1), ZX_ERR_OUT_OF_RANGE);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

TEST(RamdiskTests, RamdiskTestFifoSleepUnavailable) {
  // Set up the initial handshake connection with the ramdisk
  std::unique_ptr<RamdiskTest> ramdisk;
  ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk));

  fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk->block_fd());
  zx::unowned_channel channel(ramdisk_connection.borrow_channel());
  zx_status_t status;
  zx::fifo fifo;
  ASSERT_EQ(
      fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);
  groupid_t group = 0;

  // Create an arbitrary VMO, fill it with some stuff
  uint64_t vmo_size = PAGE_SIZE * 3;
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(vmo_size, 0, &vmo), ZX_OK) << "Failed to create VMO";
  std::unique_ptr<uint8_t[]> buf(new uint8_t[vmo_size]);
  fill_random(buf.get(), vmo_size);

  ASSERT_EQ(vmo.write(buf.get(), 0, vmo_size), ZX_OK);

  // Send a handle to the vmo to the block device, get a vmoid which identifies it
  fuchsia_hardware_block_VmoId vmoid;
  zx::vmo xfer_vmo;
  ASSERT_EQ(vmo.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
  ASSERT_EQ(
      fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status, &vmoid),
      ZX_OK);
  ASSERT_EQ(status, ZX_OK);

  block_client::Client client;
  ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client), ZX_OK);

  // Put the ramdisk to sleep after 1 block (complete transaction).
  uint64_t one = 1;
  ASSERT_EQ(ramdisk_sleep_after(ramdisk->ramdisk_client(), one), ZX_OK);

  // Batch write the VMO to the ramdisk
  // Split it into two requests, spread across the disk
  block_fifo_request_t requests[2];
  requests[0].group = group;
  requests[0].vmoid = vmoid.id;
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 1;
  requests[0].vmo_offset = 0;
  requests[0].dev_offset = 0;

  requests[1].group = group;
  requests[1].vmoid = vmoid.id;
  requests[1].opcode = BLOCKIO_WRITE;
  requests[1].length = 2;
  requests[1].vmo_offset = 1;
  requests[1].dev_offset = 100;

  // Send enough requests for the ramdisk to fall asleep before completing.
  // Other callers (e.g. block_watcher) may also send requests without affecting this test.
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_ERR_UNAVAILABLE);

  ramdisk_block_write_counts_t counts;
  ASSERT_EQ(ramdisk_get_block_counts(ramdisk->ramdisk_client(), &counts), ZX_OK);
  ASSERT_EQ(counts.received, 3ul);
  ASSERT_EQ(counts.successful, 1ul);
  ASSERT_EQ(counts.failed, 2ul);

  // Wake the ramdisk back up
  ASSERT_EQ(ramdisk_wake(ramdisk->ramdisk_client()), ZX_OK);
  requests[0].opcode = BLOCKIO_READ;
  requests[1].opcode = BLOCKIO_READ;
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);

  // Put the ramdisk to sleep after 1 block (partial transaction).
  ASSERT_EQ(ramdisk_sleep_after(ramdisk->ramdisk_client(), one), ZX_OK);

  // Batch write the VMO to the ramdisk.
  // Split it into two requests, spread across the disk.
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 2;

  requests[1].opcode = BLOCKIO_WRITE;
  requests[1].length = 1;
  requests[1].vmo_offset = 2;

  // Send enough requests for the ramdisk to fall asleep before completing.
  // Other callers (e.g. block_watcher) may also send requests without affecting this test.
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_ERR_UNAVAILABLE);

  ASSERT_EQ(ramdisk_get_block_counts(ramdisk->ramdisk_client(), &counts), ZX_OK);

  // Depending on timing, the second request might not get sent to the ramdisk because the first one
  // fails quickly before it has been sent (and the block driver will handle it), so there are two
  // possible cases we might see.
  if (counts.received == 2) {
    EXPECT_EQ(counts.successful, 1ul);
    EXPECT_EQ(counts.failed, 1ul);
  } else {
    EXPECT_EQ(counts.received, 3ul);
    EXPECT_EQ(counts.successful, 1ul);
    EXPECT_EQ(counts.failed, 2ul);
  }

  // Wake the ramdisk back up
  ASSERT_EQ(ramdisk_wake(ramdisk->ramdisk_client()), ZX_OK);
  requests[0].opcode = BLOCKIO_READ;
  requests[1].opcode = BLOCKIO_READ;
  ASSERT_EQ(client.Transaction(&requests[0], std::size(requests)), ZX_OK);

  // Close the current vmo
  requests[0].opcode = BLOCKIO_CLOSE_VMO;
  ASSERT_EQ(client.Transaction(&requests[0], 1), ZX_OK);
  fuchsia_hardware_block_BlockCloseFifo(channel->get(), &status);
}

// This thread and its arguments can be used to wake a ramdisk that sleeps with deferred writes.
// The correct calling sequence in the calling thread is:
//   thrd_create(&thread, fifo_wake_thread, &wake);
//   ramdisk_sleep_after(wake->fd, &one);
//   sync_completion_signal(&wake.start);
//   block_fifo_txn(client, requests, std::size(requests));
//   thrd_join(thread, &res);
//
// This order matters!
// * |sleep_after| must be called from the same thread as |fifo_txn| (or they may be reordered, and
//   the txn counts zeroed).
// * The do-while loop below must not be started before |sleep_after| has been called (hence the
//   'start' signal).
// * This thread must not be waiting when the calling thread blocks in |fifo_txn| (i.e. 'start' must
//   have been signaled.)

typedef struct wake_args {
  const ramdisk_client_t* ramdisk_client;
  uint64_t after;
  sync_completion_t start;
  zx_time_t deadline;
} wake_args_t;

int fifo_wake_thread(void* arg) {
  ssize_t res;

  // Always send a wake-up call; even if we failed to go to sleep.
  wake_args_t* wake = static_cast<wake_args_t*>(arg);
  auto cleanup = fit::defer([&] { ramdisk_wake(wake->ramdisk_client); });

  // Wait for the start-up signal
  zx_status_t rc = sync_completion_wait_deadline(&wake->start, wake->deadline);
  sync_completion_reset(&wake->start);
  if (rc != ZX_OK) {
    return rc;
  }

  // Loop until timeout, |wake_after| txns received, or error getting counts
  ramdisk_block_write_counts_t counts;
  do {
    zx::nanosleep(zx::deadline_after(zx::msec(100)));
    if (wake->deadline < zx_clock_get_monotonic()) {
      return ZX_ERR_TIMED_OUT;
    }
    if ((res = ramdisk_get_block_counts(wake->ramdisk_client, &counts)) != ZX_OK) {
      return static_cast<zx_status_t>(res);
    }
  } while (counts.received < wake->after);
  return ZX_OK;
}

class RamdiskTestWithClient : public testing::Test {
 public:
  static constexpr uint64_t kVmoSize = PAGE_SIZE * 16;

  void SetUp() override {
    // Set up the initial handshake connection with the ramdisk
    ASSERT_NO_FATAL_FAILURE(RamdiskTest::Create(PAGE_SIZE, 512, &ramdisk_));

    fdio_cpp::UnownedFdioCaller ramdisk_connection(ramdisk_->block_fd());
    zx::unowned_channel channel(ramdisk_connection.borrow_channel());
    zx_status_t status;
    zx::fifo fifo;
    ASSERT_EQ(
        fuchsia_hardware_block_BlockGetFifo(channel->get(), &status, fifo.reset_and_get_address()),
        ZX_OK);
    ASSERT_EQ(status, ZX_OK);

    // Create an arbitrary VMO, fill it with some stuff.
    ASSERT_EQ(ZX_OK,
              mapping_.CreateAndMap(kVmoSize, ZX_VM_PERM_READ | ZX_VM_PERM_WRITE, nullptr, &vmo_));

    buf_ = std::make_unique<uint8_t[]>(kVmoSize);
    fill_random(buf_.get(), kVmoSize);

    ASSERT_EQ(vmo_.write(buf_.get(), 0, kVmoSize), ZX_OK);

    // Send a handle to the vmo to the block device, get a vmoid which identifies it
    zx::vmo xfer_vmo;
    ASSERT_EQ(vmo_.duplicate(ZX_RIGHT_SAME_RIGHTS, &xfer_vmo), ZX_OK);
    ASSERT_EQ(
        fuchsia_hardware_block_BlockAttachVmo(channel->get(), xfer_vmo.release(), &status, &vmoid_),
        ZX_OK);
    ASSERT_EQ(status, ZX_OK);

    ASSERT_EQ(block_client::Client::Create(std::move(fifo), &client_), ZX_OK);
  }

 protected:
  std::unique_ptr<RamdiskTest> ramdisk_;
  block_client::Client client_;
  std::unique_ptr<uint8_t[]> buf_;
  zx::vmo vmo_;
  fzl::VmoMapper mapping_;
  fuchsia_hardware_block_VmoId vmoid_;
};

TEST_F(RamdiskTestWithClient, RamdiskTestFifoSleepDeferred) {
  // Create a bunch of requests, some of which are guaranteed to block.
  block_fifo_request_t requests[16];
  for (size_t i = 0; i < std::size(requests); ++i) {
    requests[i].group = 0;
    requests[i].vmoid = vmoid_.id;
    requests[i].opcode = BLOCKIO_WRITE;
    requests[i].length = 1;
    requests[i].vmo_offset = i;
    requests[i].dev_offset = i;
  }

  // Sleep and wake parameters
  uint32_t flags = fuchsia_hardware_ramdisk_RAMDISK_FLAG_RESUME_ON_WAKE;
  thrd_t thread;
  wake_args_t wake;
  wake.ramdisk_client = ramdisk_->ramdisk_client();
  wake.after = std::size(requests);
  sync_completion_reset(&wake.start);
  wake.deadline = zx_deadline_after(ZX_SEC(3));
  uint64_t blks_before_sleep = 1;
  int res;

  // Send enough requests to put the ramdisk to sleep and then be awoken wake thread. The ordering
  // below matters!  See the comment on |ramdisk_wake_thread| for details.
  ASSERT_EQ(thrd_create(&thread, fifo_wake_thread, &wake), thrd_success);
  ASSERT_EQ(ramdisk_set_flags(ramdisk_->ramdisk_client(), flags), ZX_OK);
  ASSERT_EQ(ramdisk_sleep_after(ramdisk_->ramdisk_client(), blks_before_sleep), ZX_OK);
  sync_completion_signal(&wake.start);
  ASSERT_EQ(client_.Transaction(&requests[0], std::size(requests)), ZX_OK);
  ASSERT_EQ(thrd_join(thread, &res), thrd_success);

  // Check that the wake thread succeeded.
  ASSERT_EQ(res, 0) << "Background thread failed";

  for (size_t i = 0; i < std::size(requests); ++i) {
    requests[i].opcode = BLOCKIO_READ;
  }

  // Read data we wrote to disk back into the VMO.
  ASSERT_EQ(client_.Transaction(&requests[0], std::size(requests)), ZX_OK);

  // Verify that the contents of the vmo match the buffer.
  ASSERT_EQ(memcmp(mapping_.start(), buf_.get(), kVmoSize), 0);

  // Now send 1 transaction with the full length of the VMO.
  requests[0].opcode = BLOCKIO_WRITE;
  requests[0].length = 16;
  requests[0].vmo_offset = 0;
  requests[0].dev_offset = 0;

  // Restart the wake thread and put ramdisk to sleep again.
  wake.after = 1;
  sync_completion_reset(&wake.start);
  ASSERT_EQ(thrd_create(&thread, fifo_wake_thread, &wake), thrd_success);
  ASSERT_EQ(ramdisk_sleep_after(ramdisk_->ramdisk_client(), blks_before_sleep), ZX_OK);
  sync_completion_signal(&wake.start);
  ASSERT_EQ(client_.Transaction(&requests[0], 1), ZX_OK);
  ASSERT_EQ(thrd_join(thread, &res), thrd_success);

  // Check the wake thread succeeded, and that the contents of the ramdisk match the buffer.
  ASSERT_EQ(res, 0) << "Background thread failed";
  requests[0].opcode = BLOCKIO_READ;
  ASSERT_EQ(client_.Transaction(&requests[0], 1), ZX_OK);
  ASSERT_EQ(memcmp(mapping_.start(), buf_.get(), kVmoSize), 0);

  // Check that we can do I/O normally again.
  requests[0].opcode = BLOCKIO_WRITE;
  ASSERT_EQ(client_.Transaction(&requests[0], 1), ZX_OK);
}

TEST(RamdiskTests, RamdiskCreateAt) {
  fbl::unique_fd devfs_fd(open("/dev", O_RDONLY | O_DIRECTORY));
  ASSERT_TRUE(devfs_fd);
  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create_at(devfs_fd.get(), PAGE_SIZE / 2, 512, &ramdisk), ZX_OK);

  ASSERT_EQ(
      wait_for_device((std::string("/dev/") + ramdisk_get_path(ramdisk)).c_str(), ZX_TIME_INFINITE),
      ZX_OK);
  ramdisk_destroy(ramdisk);
}

TEST(RamdiskTests, RamdiskCreateAtGuid) {
  constexpr uint8_t kGuid[ZBI_PARTITION_GUID_LEN] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
                                                     0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF};
  fbl::unique_fd devfs_fd(open("/dev", O_RDONLY | O_DIRECTORY));
  ASSERT_TRUE(devfs_fd);

  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create_at_with_guid(devfs_fd.get(), PAGE_SIZE / 2, 512, kGuid, sizeof(kGuid),
                                        &ramdisk),
            ZX_OK);

  ASSERT_EQ(
      wait_for_device((std::string("/dev/") + ramdisk_get_path(ramdisk)).c_str(), ZX_TIME_INFINITE),
      ZX_OK);
  ramdisk_destroy(ramdisk);
}

TEST(RamdiskTests, RamdiskCreateAtVmo) {
  zx::vmo vmo;
  ASSERT_EQ(zx::vmo::create(256 * PAGE_SIZE, 0, &vmo), ZX_OK);

  fbl::unique_fd devfs_fd(open("/dev", O_RDONLY | O_DIRECTORY));
  ASSERT_TRUE(devfs_fd);
  ramdisk_client_t* ramdisk = nullptr;
  ASSERT_EQ(ramdisk_create_at_from_vmo(devfs_fd.get(), vmo.release(), &ramdisk), ZX_OK);

  ASSERT_EQ(
      wait_for_device((std::string("/dev/") + ramdisk_get_path(ramdisk)).c_str(), ZX_TIME_INFINITE),
      ZX_OK);
  ramdisk_destroy(ramdisk);
}

TEST_F(RamdiskTestWithClient, DiscardOnWake) {
  ASSERT_EQ(ramdisk_set_flags(ramdisk_->ramdisk_client(),
                              fuchsia_hardware_ramdisk_RAMDISK_FLAG_DISCARD_NOT_FLUSHED_ON_WAKE),
            ZX_OK);
  ASSERT_EQ(ramdisk_sleep_after(ramdisk_->ramdisk_client(), 100), ZX_OK);

  block_fifo_request_t requests[5];
  for (size_t i = 0; i < std::size(requests); ++i) {
    if (i == 2) {
      // Insert a flush midway through.
      requests[i].opcode = BLOCKIO_FLUSH;
    } else {
      requests[i].group = 0;
      requests[i].vmoid = vmoid_.id;
      requests[i].opcode = BLOCKIO_WRITE;
      requests[i].length = 1;
      requests[i].vmo_offset = i;
      requests[i].dev_offset = i;
    }
  }
  ASSERT_EQ(client_.Transaction(requests, std::size(requests)), ZX_OK);

  // Wake the device and it should discard the last two blocks.
  ASSERT_EQ(ramdisk_wake(ramdisk_->ramdisk_client()), ZX_OK);

  memset(mapping_.start(), 0, kVmoSize);

  // Read back all the blocks. The extra flush shouldn't matter.
  for (size_t i = 0; i < std::size(requests); ++i) {
    if (i != 2)
      requests[i].opcode = BLOCKIO_READ;
  }
  ASSERT_EQ(client_.Transaction(requests, std::size(requests)), ZX_OK);

  // Verify that the first two blocks went through but the last two did not.
  for (size_t i = 0; i < std::size(requests); ++i) {
    if (i < 2) {
      EXPECT_EQ(memcmp(static_cast<uint8_t*>(mapping_.start()) + PAGE_SIZE * i,
                       &buf_[PAGE_SIZE * i], PAGE_SIZE),
                0);
    } else if (i > 2) {
      EXPECT_NE(memcmp(static_cast<uint8_t*>(mapping_.start()) + PAGE_SIZE * i,
                       &buf_[PAGE_SIZE * i], PAGE_SIZE),
                0)
          << i;
    }
  }
}

TEST_F(RamdiskTestWithClient, DiscardRandomOnWake) {
  ASSERT_EQ(ramdisk_set_flags(ramdisk_->ramdisk_client(),
                              fuchsia_hardware_ramdisk_RAMDISK_FLAG_DISCARD_NOT_FLUSHED_ON_WAKE |
                                  fuchsia_hardware_ramdisk_RAMDISK_FLAG_DISCARD_RANDOM),
            ZX_OK);

  int found = 0;
  do {
    ASSERT_EQ(ramdisk_sleep_after(ramdisk_->ramdisk_client(), 100), ZX_OK);
    fill_random(buf_.get(), kVmoSize);
    ASSERT_EQ(vmo_.write(buf_.get(), 0, kVmoSize), ZX_OK);

    block_fifo_request_t requests[5];
    for (size_t i = 0; i < std::size(requests); ++i) {
      if (i == 2) {
        // Insert a flush midway through.
        requests[i].opcode = BLOCKIO_FLUSH;
      } else {
        requests[i].group = 0;
        requests[i].vmoid = vmoid_.id;
        requests[i].opcode = BLOCKIO_WRITE;
        requests[i].length = 1;
        requests[i].vmo_offset = i;
        requests[i].dev_offset = i;
      }
    }
    ASSERT_EQ(client_.Transaction(requests, std::size(requests)), ZX_OK);

    // Wake the device and it should discard the last two blocks.
    ASSERT_EQ(ramdisk_wake(ramdisk_->ramdisk_client()), ZX_OK);

    memset(mapping_.start(), 0, kVmoSize);

    // Read back all the blocks. The extra flush shouldn't matter.
    for (size_t i = 0; i < std::size(requests); ++i) {
      if (i != 2)
        requests[i].opcode = BLOCKIO_READ;
    }
    ASSERT_EQ(client_.Transaction(requests, std::size(requests)), ZX_OK);

    // Verify that the first two blocks went through but the last two might not.
    int different = 0;
    for (size_t i = 0; i < std::size(requests); ++i) {
      if (i < 2) {
        EXPECT_EQ(memcmp(static_cast<uint8_t*>(mapping_.start()) + PAGE_SIZE * i,
                         &buf_[PAGE_SIZE * i], PAGE_SIZE),
                  0);
      } else if (i > 2) {
        if (memcmp(static_cast<uint8_t*>(mapping_.start()) + PAGE_SIZE * i, &buf_[PAGE_SIZE * i],
                   PAGE_SIZE)) {
          different |= 1 << (i - 3);
        }
      }
    }

    // There are 4 different combinations we expect and we keep looping until we've seen all of
    // them.
    found |= 1 << different;
  } while (found != 0xf);
}

}  // namespace
}  // namespace ramdisk