test/src/fcntl/linux/fallocate_test.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file contains the tests for the fallocate POSIX functions
///
//===----------------------------------------------------------------------===//

#include "hdr/fcntl_macros.h"
#include "src/__support/CPP/scope.h"
#include "src/__support/libc_errno.h"
#include "src/fcntl/fallocate.h"
#include "src/fcntl/open.h"
#include "src/sys/stat/fstat.h"
#include "src/sys/stat/stat.h"
#include "src/unistd/close.h"
#include "src/unistd/unlink.h"
#include "test/UnitTest/ErrnoCheckingTest.h"
#include "test/UnitTest/ErrnoSetterMatcher.h"
#include "test/UnitTest/Test.h"

#include <linux/falloc.h>

using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;

TEST(LlvmLibcFallocateTest, BasicAllocate) {
  constexpr char TEST_FILE[] = "fallocate_basic.test";

  int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_WRONLY | O_TRUNC, 0600);
  ASSERT_ERRNO_SUCCESS();
  ASSERT_GT(fd, 0);
  LIBC_NAMESPACE::cpp::scope_exit cleanup_fd([&] {
    EXPECT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
    EXPECT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  });

  // Mode 0: expand file size to offset + len (4096 bytes)
  ASSERT_THAT(LIBC_NAMESPACE::fallocate(fd, 0, 1024, 3072), Succeeds(0));

  struct stat st;
  ASSERT_EQ(LIBC_NAMESPACE::fstat(fd, &st), 0);
  ASSERT_EQ(static_cast<off_t>(st.st_size), static_cast<off_t>(4096));
}

TEST(LlvmLibcFallocateTest, KeepSize) {
  constexpr char TEST_FILE[] = "fallocate_keep_size.test";

  int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_WRONLY | O_TRUNC, 0600);
  ASSERT_ERRNO_SUCCESS();
  ASSERT_GT(fd, 0);
  LIBC_NAMESPACE::cpp::scope_exit cleanup_fd([&] {
    EXPECT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
    EXPECT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  });

  // Pre-allocate space at offset 8192, length 4096, but keep file size at 0
  ASSERT_THAT(LIBC_NAMESPACE::fallocate(fd, FALLOC_FL_KEEP_SIZE, 8192, 4096),
              Succeeds(0));

  struct stat st;
  ASSERT_EQ(LIBC_NAMESPACE::fstat(fd, &st), 0);
  ASSERT_EQ(static_cast<off_t>(st.st_size), static_cast<off_t>(0));
}

TEST(LlvmLibcFallocateTest, InvalidFd) {
  // Passing an invalid file descriptor should fail with EBADF
  ASSERT_THAT(LIBC_NAMESPACE::fallocate(-1, 0, 0, 4096), Fails(EBADF));
}

TEST(LlvmLibcFallocateTest, InvalidMode) {
  constexpr char TEST_FILE[] = "fallocate_invalid_mode.test";

  int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_WRONLY | O_TRUNC, 0600);
  ASSERT_ERRNO_SUCCESS();
  ASSERT_GT(fd, 0);
  LIBC_NAMESPACE::cpp::scope_exit cleanup_fd([&] {
    EXPECT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
    EXPECT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
  });

  ASSERT_EQ(LIBC_NAMESPACE::fallocate(fd, -1, 0, 4096), -1);
  // Could be any one of those and potentially more depending on the file system
  ASSERT_TRUE(libc_errno == EINVAL || libc_errno == ENOTSUP ||
              libc_errno == EOPNOTSUPP);
  // for the cleanup to work
  libc_errno = 0;
}