/* Tests for copy_file_range.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <array_length.h>

#include <errno.h>

#include <fcntl.h>

#include <inttypes.h>

#include <libgen.h>

#include <poll.h>

#include <sched.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <support/check.h>

#include <support/namespace.h>

#include <support/support.h>

#include <support/temp_file.h>

#include <support/test-driver.h>

#include <support/xunistd.h>

#ifdef CLONE_NEWNS

# include <sys/mount.h>

#endif

/* Boolean flags which indicate whether to use pointers with explicit

   output flags.  */

static int do_inoff;

static int do_outoff;

/* Name and descriptors of the input files.  Files are truncated and

   reopened (with O_RDWR) between tests.  */

static char *infile;

static int infd;

static char *outfile;

static int outfd;

/* Like the above, but on a different file system.  xdevfile can be

   NULL if no suitable file system has been found.  */

static char *xdevfile;

/* Input and output offsets.  Set according to do_inoff and do_outoff

   before the test.  The offsets themselves are always set to

   zero.  */

static off64_t inoff;

static off64_t *pinoff;

static off64_t outoff;

static off64_t *poutoff;

/* These are a collection of copy sizes used in tests.  The selection

   takes into account that the fallback implementation uses an

   internal buffer of 8192 bytes.  */

enum { maximum_size = 99999 };

static const int typical_sizes[] =

  { 0, 1, 2, 3, 1024, 2048, 4096, 8191, 8192, 8193, 16383, 16384, 16385,

    maximum_size };

/* The random contents of this array can be used as a pattern to check

   for correct write operations.  */

static unsigned char random_data[maximum_size];

/* The size chosen by the test harness.  */

static int current_size;

/* Maximum writable file offset.  Updated by find_maximum_offset

   below.  */

static off64_t maximum_offset;

/* Error code when crossing the offset.  */

static int maximum_offset_errno;

/* If true: Writes which cross the limit will fail.  If false: Writes

   which cross the limit will result in a partial write.  */

static bool maximum_offset_hard_limit;

/* Fills maximum_offset etc. above.  Truncates outfd as a side

   effect.  */

static void

find_maximum_offset (void)

{

  xftruncate (outfd, 0);

  if (maximum_offset != 0)

    return;

  uint64_t upper = -1;

  upper >>= 1;                  /* Maximum of off64_t.  */

  TEST_VERIFY ((off64_t) upper > 0);

  TEST_VERIFY ((off64_t) (upper + 1) < 0);

  if (lseek64 (outfd, upper, SEEK_SET) >= 0)

    {

      if (write (outfd, "", 1) == 1)

        FAIL_EXIT1 ("created a file larger than the off64_t range");

    }

  uint64_t lower = 1024 * 1024; /* A reasonable minimum file size.  */

  /* Loop invariant: writing at lower succeeds, writing at upper fails.  */

  while (lower + 1 < upper)

    {

      uint64_t middle = (lower + upper) / 2;

      if (test_verbose > 0)

        printf ("info: %s: remaining test range %" PRIu64 " .. %" PRIu64

                ", probe at %" PRIu64 "\n", __func__, lower, upper, middle);

      xftruncate (outfd, 0);

      if (lseek64 (outfd, middle, SEEK_SET) >= 0

          && write (outfd, "", 1) == 1)

        lower = middle;

      else

        upper = middle;

    }

  TEST_VERIFY (lower + 1 == upper);

  maximum_offset = lower;

  printf ("info: maximum writable file offset: %" PRIu64 " (%" PRIx64 ")\n",

          lower, lower);

  /* Check that writing at the valid offset actually works.  */

  xftruncate (outfd, 0);

  xlseek (outfd, lower, SEEK_SET);

  TEST_COMPARE (write (outfd, "", 1), 1);

  /* Cross the boundary with a two-byte write.  This can either result

     in a short write, or a failure.  */

  xlseek (outfd, lower, SEEK_SET);

  ssize_t ret = write (outfd, " ", 2);

  if (ret < 0)

    {

      maximum_offset_errno = errno;

      maximum_offset_hard_limit = true;

    }

  else

    maximum_offset_hard_limit = false;

  /* Check that writing at the next offset actually fails.  This also

     obtains the expected errno value.  */

  xftruncate (outfd, 0);

  const char *action;

  if (lseek64 (outfd, lower + 1, SEEK_SET) != 0)

    {

      if (write (outfd, "", 1) != -1)

        FAIL_EXIT1 ("write to impossible offset %" PRIu64 " succeeded",

                    lower + 1);

      action = "writing";

      int errno_copy = errno;

      if (maximum_offset_hard_limit)

        TEST_COMPARE (errno_copy, maximum_offset_errno);

      else

        maximum_offset_errno = errno_copy;

    }

  else

    {

      action = "seeking";

      maximum_offset_errno = errno;

    }

  printf ("info: %s out of range fails with %m (%d)\n",

          action, maximum_offset_errno);

  xftruncate (outfd, 0);

  xlseek (outfd, 0, SEEK_SET);

}

/* Perform a copy of a file.  */

static void

simple_file_copy (void)

{

  xwrite (infd, random_data, current_size);

  int length;

  int in_skipped; /* Expected skipped bytes in input.  */

  if (do_inoff)

    {

      xlseek (infd, 1, SEEK_SET);

      inoff = 2;

      length = current_size - 3;

      in_skipped = 2;

    }

  else

    {

      xlseek (infd, 3, SEEK_SET);

      length = current_size - 5;

      in_skipped = 3;

    }

  int out_skipped; /* Expected skipped bytes before the written data.  */

  if (do_outoff)

    {

      xlseek (outfd, 4, SEEK_SET);

      outoff = 5;

      out_skipped = 5;

    }

  else

    {

      xlseek (outfd, 6, SEEK_SET);

      length = current_size - 6;

      out_skipped = 6;

    }

  if (length < 0)

    length = 0;

  TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                 length, 0), length);

  if (do_inoff)

    {

      TEST_COMPARE (inoff, 2 + length);

      TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 1);

    }

  else

    TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 3 + length);

  if (do_outoff)

    {

      TEST_COMPARE (outoff, 5 + length);

      TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 4);

    }

  else

    TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 6 + length);

  struct stat64 st;

  xfstat (outfd, &st);

  if (length > 0)

    TEST_COMPARE (st.st_size, out_skipped + length);

  else

    {

      /* If we did not write anything, we also did not add any

         padding.  */

      TEST_COMPARE (st.st_size, 0);

      return;

    }

  xlseek (outfd, 0, SEEK_SET);

  char *bytes = xmalloc (st.st_size);

  TEST_COMPARE (read (outfd, bytes, st.st_size), st.st_size);

  for (int i = 0; i < out_skipped; ++i)

    TEST_COMPARE (bytes[i], 0);

  TEST_VERIFY (memcmp (bytes + out_skipped, random_data + in_skipped,

                       length) == 0);

  free (bytes);

}

/* Test that reading from a pipe willfails.  */

static void

pipe_as_source (void)

{

  int pipefds[2];

  xpipe (pipefds);

  for (int length = 0; length < 2; ++length)

    {

      if (test_verbose > 0)

        printf ("info: %s: length=%d\n", __func__, length);

      /* Make sure that there is something to copy in the pipe.  */

      xwrite (pipefds[1], "@", 1);

      TEST_COMPARE (copy_file_range (pipefds[0], pinoff, outfd, poutoff,

                                     length, 0), -1);

      /* Linux 4.10 and later return EINVAL.  Older kernels return

         EXDEV.  */

      TEST_VERIFY (errno == EINVAL || errno == EXDEV);

      TEST_COMPARE (inoff, 0);

      TEST_COMPARE (outoff, 0);

      TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 0);

      /* Make sure that nothing was read.  */

      char buf = 'A';

      TEST_COMPARE (read (pipefds[0], &buf, 1), 1);

      TEST_COMPARE (buf, '@');

    }

  xclose (pipefds[0]);

  xclose (pipefds[1]);

}

/* Test that writing to a pipe fails.  */

static void

pipe_as_destination (void)

{

  /* Make sure that there is something to read in the input file.  */

  xwrite (infd, "abc", 3);

  xlseek (infd, 0, SEEK_SET);

  int pipefds[2];

  xpipe (pipefds);

  for (int length = 0; length < 2; ++length)

    {

      if (test_verbose > 0)

        printf ("info: %s: length=%d\n", __func__, length);

      TEST_COMPARE (copy_file_range (infd, pinoff, pipefds[1], poutoff,

                                     length, 0), -1);

      /* Linux 4.10 and later return EINVAL.  Older kernels return

         EXDEV.  */

      TEST_VERIFY (errno == EINVAL || errno == EXDEV);

      TEST_COMPARE (inoff, 0);

      TEST_COMPARE (outoff, 0);

      TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 0);

      /* Make sure that nothing was written.  */

      struct pollfd pollfd = { .fd = pipefds[0], .events = POLLIN, };

      TEST_COMPARE (poll (&pollfd, 1, 0), 0);

    }

  xclose (pipefds[0]);

  xclose (pipefds[1]);

}

/* Test a write failure after (potentially) writing some bytes.

   Failure occurs near the start of the buffer.  */

static void

delayed_write_failure_beginning (void)

{

  /* We need to write something to provoke the error.  */

  if (current_size == 0)

    return;

  xwrite (infd, random_data, sizeof (random_data));

  xlseek (infd, 0, SEEK_SET);

  /* Write failure near the start.  The actual error code varies among

     file systems.  */

  find_maximum_offset ();

  off64_t where = maximum_offset;

  if (current_size == 1)

    ++where;

  outoff = where;

  if (do_outoff)

    xlseek (outfd, 1, SEEK_SET);

  else

    xlseek (outfd, where, SEEK_SET);

  if (maximum_offset_hard_limit || where > maximum_offset)

    {

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     sizeof (random_data), 0), -1);

      TEST_COMPARE (errno, maximum_offset_errno);

      TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 0);

      TEST_COMPARE (inoff, 0);

      if (do_outoff)

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 1);

      else

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), where);

      TEST_COMPARE (outoff, where);

      struct stat64 st;

      xfstat (outfd, &st);

      TEST_COMPARE (st.st_size, 0);

    }

  else

    {

      /* The offset is not a hard limit.  This means we write one

         byte.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     sizeof (random_data), 0), 1);

      if (do_inoff)

        {

          TEST_COMPARE (inoff, 1);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 0);

        }

      else

        {

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 1);

          TEST_COMPARE (inoff, 0);

        }

      if (do_outoff)

        {

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 1);

          TEST_COMPARE (outoff, where + 1);

        }

      else

        {

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), where + 1);

          TEST_COMPARE (outoff, where);

        }

      struct stat64 st;

      xfstat (outfd, &st);

      TEST_COMPARE (st.st_size, where + 1);

    }

}

/* Test a write failure after (potentially) writing some bytes.

   Failure occurs near the end of the buffer.  */

static void

delayed_write_failure_end (void)

{

  if (current_size <= 1)

    /* This would be same as the first test because there is not

       enough data to write to make a difference.  */

    return;

  xwrite (infd, random_data, sizeof (random_data));

  xlseek (infd, 0, SEEK_SET);

  find_maximum_offset ();

  off64_t where = maximum_offset - current_size + 1;

  if (current_size == sizeof (random_data))

    /* Otherwise we do not reach the non-writable byte.  */

    ++where;

  outoff = where;

  if (do_outoff)

    xlseek (outfd, 1, SEEK_SET);

  else

    xlseek (outfd, where, SEEK_SET);

  ssize_t ret = copy_file_range (infd, pinoff, outfd, poutoff,

                                 sizeof (random_data), 0);

  if (ret < 0)

    {

      TEST_COMPARE (ret, -1);

      TEST_COMPARE (errno, maximum_offset_errno);

      struct stat64 st;

      xfstat (outfd, &st);

      TEST_COMPARE (st.st_size, 0);

    }

  else

    {

      /* The first copy succeeded.  This happens in the emulation

         because the internal buffer of limited size does not

         necessarily cross the off64_t boundary on the first write

         operation.  */

      if (test_verbose > 0)

        printf ("info:   copy_file_range (%zu) returned %zd\n",

                sizeof (random_data), ret);

      TEST_VERIFY (ret > 0);

      TEST_VERIFY (ret < maximum_size);

      struct stat64 st;

      xfstat (outfd, &st);

      TEST_COMPARE (st.st_size, where + ret);

      if (do_inoff)

        {

          TEST_COMPARE (inoff, ret);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 0);

        }

      else

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), ret);

      char *buffer = xmalloc (ret);

      TEST_COMPARE (pread64 (outfd, buffer, ret, where), ret);

      TEST_VERIFY (memcmp (buffer, random_data, ret) == 0);

      free (buffer);

      /* The second copy fails.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     sizeof (random_data), 0), -1);

      TEST_COMPARE (errno, maximum_offset_errno);

    }

}

/* Test a write failure across devices.  */

static void

cross_device_failure (void)

{

  if (xdevfile == NULL)

    /* Subtest not supported due to missing cross-device file.  */

    return;

  /* We need something to write.  */

  xwrite (infd, random_data, sizeof (random_data));

  xlseek (infd, 0, SEEK_SET);

  int xdevfd = xopen (xdevfile, O_RDWR | O_LARGEFILE, 0);

  TEST_COMPARE (copy_file_range (infd, pinoff, xdevfd, poutoff,

                                 current_size, 0), -1);

  TEST_COMPARE (errno, EXDEV);

  TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 0);

  struct stat64 st;

  xfstat (xdevfd, &st);

  TEST_COMPARE (st.st_size, 0);

  xclose (xdevfd);

}

/* Try to exercise ENOSPC behavior with a tempfs file system (so that

   we do not have to fill up a regular file system to get the error).

   This function runs in a subprocess, so that we do not change the

   mount namespace of the actual test process.  */

static void

enospc_failure_1 (void *closure)

{

#ifdef CLONE_NEWNS

  support_become_root ();

  /* Make sure that we do not alter the file system mounts of the

     parents.  */

  if (! support_enter_mount_namespace ())

    {

      printf ("warning: ENOSPC test skipped\n");

      return;

    }

  char *mountpoint = closure;

  if (mount ("none", mountpoint, "tmpfs", MS_NODEV | MS_NOEXEC,

             "size=500k") != 0)

    {

      printf ("warning: could not mount tmpfs at %s: %m\n", mountpoint);

      return;

    }

  /* The source file must reside on the same file system.  */

  char *intmpfsfile = xasprintf ("%s/%s", mountpoint, "in");

  int intmpfsfd = xopen (intmpfsfile, O_RDWR | O_CREAT | O_LARGEFILE, 0600);

  xwrite (intmpfsfd, random_data, sizeof (random_data));

  xlseek (intmpfsfd, 1, SEEK_SET);

  inoff = 1;

  char *outtmpfsfile = xasprintf ("%s/%s", mountpoint, "out");

  int outtmpfsfd = xopen (outtmpfsfile, O_RDWR | O_CREAT | O_LARGEFILE, 0600);

  /* Fill the file with data until ENOSPC is reached.  */

  while (true)

    {

      ssize_t ret = write (outtmpfsfd, random_data, sizeof (random_data));

      if (ret < 0 && errno != ENOSPC)

        FAIL_EXIT1 ("write to %s: %m", outtmpfsfile);

      if (ret < sizeof (random_data))

        break;

    }

  TEST_COMPARE (write (outtmpfsfd, "", 1), -1);

  TEST_COMPARE (errno, ENOSPC);

  off64_t maxsize = xlseek (outtmpfsfd, 0, SEEK_CUR);

  TEST_VERIFY_EXIT (maxsize > sizeof (random_data));

  /* Constructed the expected file contents.  */

  char *expected = xmalloc (maxsize);

  TEST_COMPARE (pread64 (outtmpfsfd, expected, maxsize, 0), maxsize);

  /* Go back a little, so some bytes can be written.  */

  enum { offset = 20000 };

  TEST_VERIFY_EXIT (offset < maxsize);

  TEST_VERIFY_EXIT (offset < sizeof (random_data));

  memcpy (expected + maxsize - offset, random_data + 1, offset);

  if (do_outoff)

    {

      outoff = maxsize - offset;

      xlseek (outtmpfsfd, 2, SEEK_SET);

    }

  else

    xlseek (outtmpfsfd, -offset, SEEK_CUR);

  /* First call is expected to succeed because we made room for some

     bytes.  */

  TEST_COMPARE (copy_file_range (intmpfsfd, pinoff, outtmpfsfd, poutoff,

                                 maximum_size, 0), offset);

  if (do_inoff)

    {

      TEST_COMPARE (inoff, 1 + offset);

      TEST_COMPARE (xlseek (intmpfsfd, 0, SEEK_CUR), 1);

    }

  else

      TEST_COMPARE (xlseek (intmpfsfd, 0, SEEK_CUR), 1 + offset);

  if (do_outoff)

    {

      TEST_COMPARE (outoff, maxsize);

      TEST_COMPARE (xlseek (outtmpfsfd, 0, SEEK_CUR), 2);

    }

  else

    TEST_COMPARE (xlseek (outtmpfsfd, 0, SEEK_CUR), maxsize);

  struct stat64 st;

  xfstat (outtmpfsfd, &st);

  TEST_COMPARE (st.st_size, maxsize);

  char *actual = xmalloc (st.st_size);

  TEST_COMPARE (pread64 (outtmpfsfd, actual, st.st_size, 0), st.st_size);

  TEST_VERIFY (memcmp (expected, actual, maxsize) == 0);

  /* Second call should fail with ENOSPC.  */

  TEST_COMPARE (copy_file_range (intmpfsfd, pinoff, outtmpfsfd, poutoff,

                                 maximum_size, 0), -1);

  TEST_COMPARE (errno, ENOSPC);

  /* Offsets should be unchanged.  */

  if (do_inoff)

    {

      TEST_COMPARE (inoff, 1 + offset);

      TEST_COMPARE (xlseek (intmpfsfd, 0, SEEK_CUR), 1);

    }

  else

    TEST_COMPARE (xlseek (intmpfsfd, 0, SEEK_CUR), 1 + offset);

  if (do_outoff)

    {

      TEST_COMPARE (outoff, maxsize);

      TEST_COMPARE (xlseek (outtmpfsfd, 0, SEEK_CUR), 2);

    }

  else

    TEST_COMPARE (xlseek (outtmpfsfd, 0, SEEK_CUR), maxsize);

  TEST_COMPARE (xlseek (outtmpfsfd, 0, SEEK_END), maxsize);

  TEST_COMPARE (pread64 (outtmpfsfd, actual, maxsize, 0), maxsize);

  TEST_VERIFY (memcmp (expected, actual, maxsize) == 0);

  free (actual);

  free (expected);

  xclose (intmpfsfd);

  xclose (outtmpfsfd);

  free (intmpfsfile);

  free (outtmpfsfile);

#else /* !CLONE_NEWNS */

  puts ("warning: ENOSPC test skipped (no mount namespaces)");

#endif

}

/* Call enospc_failure_1 in a subprocess.  */

static void

enospc_failure (void)

{

  char *mountpoint

    = support_create_temp_directory ("tst-copy_file_range-enospc-");

  support_isolate_in_subprocess (enospc_failure_1, mountpoint);

  free (mountpoint);

}

/* The target file descriptor must have O_APPEND enabled.  */

static void

oappend_failure (void)

{

  /* Add data, to make sure we do not fail because there is

     insufficient input data.  */

  xwrite (infd, random_data, current_size);

  xlseek (infd, 0, SEEK_SET);

  xclose (outfd);

  outfd = xopen (outfile, O_RDWR | O_APPEND, 0);

  TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                 current_size, 0), -1);

  TEST_COMPARE (errno, EBADF);

}

/* Test that a short input file results in a shortened copy.  */

static void

short_copy (void)

{

  if (current_size == 0)

    /* Nothing to shorten.  */

    return;

  /* Two subtests, one with offset 0 and current_size - 1 bytes, and

     another one with current_size bytes, but offset 1.  */

  for (int shift = 0; shift < 2; ++shift)

    {

      if (test_verbose > 0)

        printf ("info:   shift=%d\n", shift);

      xftruncate (infd, 0);

      xlseek (infd, 0, SEEK_SET);

      xwrite (infd, random_data, current_size - !shift);

      if (do_inoff)

        {

          inoff = shift;

          xlseek (infd, 2, SEEK_SET);

        }

      else

        {

          inoff = 3;

          xlseek (infd, shift, SEEK_SET);

        }

      ftruncate (outfd, 0);

      xlseek (outfd, 0, SEEK_SET);

      outoff = 0;

      /* First call copies current_size - 1 bytes.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     current_size, 0), current_size - 1);

      char *buffer = xmalloc (current_size);

      TEST_COMPARE (pread64 (outfd, buffer, current_size, 0),

                    current_size - 1);

      TEST_VERIFY (memcmp (buffer, random_data + shift, current_size - 1)

                   == 0);

      free (buffer);

      if (do_inoff)

        {

          TEST_COMPARE (inoff, current_size - 1 + shift);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 2);

        }

      else

        TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), current_size - 1 + shift);

      if (do_outoff)

        {

          TEST_COMPARE (outoff, current_size - 1);

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 0);

        }

      else

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), current_size - 1);

      /* First call copies zero bytes.  */

      TEST_COMPARE (copy_file_range (infd, pinoff, outfd, poutoff,

                                     current_size, 0), 0);

      /* And the offsets are unchanged.  */

      if (do_inoff)

        {

          TEST_COMPARE (inoff, current_size - 1 + shift);

          TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), 2);

        }

      else

        TEST_COMPARE (xlseek (infd, 0, SEEK_CUR), current_size - 1 + shift);

      if (do_outoff)

        {

          TEST_COMPARE (outoff, current_size - 1);

          TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), 0);

        }

      else

        TEST_COMPARE (xlseek (outfd, 0, SEEK_CUR), current_size - 1);

    }

}

/* A named test function.  */

struct test_case

{

  const char *name;

  void (*func) (void);

  bool sizes; /* If true, call the test with different current_size values.  */

};

/* The available test cases.  */

static struct test_case tests[] =

  {

    { "simple_file_copy", simple_file_copy, .sizes = true },

    { "pipe_as_source", pipe_as_source, },

    { "pipe_as_destination", pipe_as_destination, },

    { "delayed_write_failure_beginning", delayed_write_failure_beginning,

      .sizes = true },

    { "delayed_write_failure_end", delayed_write_failure_end, .sizes = true },

    { "cross_device_failure", cross_device_failure, .sizes = true },

    { "enospc_failure", enospc_failure, },

    { "oappend_failure", oappend_failure, .sizes = true },

    { "short_copy", short_copy, .sizes = true },

  };

static int

do_test (void)

{

  for (unsigned char *p = random_data; p < array_end (random_data); ++p)

    *p = rand () >> 24;

  infd = create_temp_file ("tst-copy_file_range-in-", &infile);

  xclose (create_temp_file ("tst-copy_file_range-out-", &outfile));

  /* Try to find a different directory from the default input/output

     file.  */

  {

    struct stat64 instat;

    xfstat (infd, &instat);

    static const char *const candidates[] =

      { NULL, "/var/tmp", "/dev/shm" };

    for (const char *const *c = candidates; c < array_end (candidates); ++c)

      {

        const char *path = *c;

        char *to_free = NULL;

        if (path == NULL)

          {

            to_free = xreadlink ("/proc/self/exe");

            path = dirname (to_free);

          }

        struct stat64 cstat;

        xstat (path, &cstat);

        if (cstat.st_dev == instat.st_dev)

          {

            free (to_free);

            continue;

          }

        printf ("info: using alternate temporary files directory: %s\n", path);

        xdevfile = xasprintf ("%s/tst-copy_file_range-xdev-XXXXXX", path);

        free (to_free);

        break;

      }

    if (xdevfile != NULL)

      {

        int xdevfd = mkstemp (xdevfile);

        if (xdevfd < 0)

          FAIL_EXIT1 ("mkstemp (\"%s\"): %m", xdevfile);

        struct stat64 xdevst;

        xfstat (xdevfd, &xdevst);

        TEST_VERIFY (xdevst.st_dev != instat.st_dev);

        add_temp_file (xdevfile);

        xclose (xdevfd);

      }

    else

      puts ("warning: no alternate directory on different file system found");

  }

  xclose (infd);

  for (do_inoff = 0; do_inoff < 2; ++do_inoff)

    for (do_outoff = 0; do_outoff < 2; ++do_outoff)

      for (struct test_case *test = tests; test < array_end (tests); ++test)

        for (const int *size = typical_sizes;

             size < array_end (typical_sizes); ++size)

          {

            current_size = *size;

            if (test_verbose > 0)

              printf ("info: %s do_inoff=%d do_outoff=%d current_size=%d\n",

                      test->name, do_inoff, do_outoff, current_size);

            inoff = 0;

            if (do_inoff)

              pinoff = &inof;;

            else

              pinoff = NULL;

            outoff = 0;

            if (do_outoff)

              poutoff = &outoff;

            else

              poutoff = NULL;

            infd = xopen (infile, O_RDWR | O_LARGEFILE, 0);

            xftruncate (infd, 0);

            outfd = xopen (outfile, O_RDWR | O_LARGEFILE, 0);

            xftruncate (outfd, 0);

            test->func ();

            xclose (infd);

            xclose (outfd);

            if (!test->sizes)

              /* Skip the other sizes unless they have been

                 requested.  */

              break;

          }

  free (infile);

  free (outfile);

  free (xdevfile);

  return 0;

}

#include <support/test-driver.c>