/* Linux implementation of 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 <errno.h>

#include <sysdep-cancel.h>

#include <unistd.h>

/* Include the fallback implementation.  */

#ifndef __ASSUME_COPY_FILE_RANGE

#define COPY_FILE_RANGE_DECL static

#define COPY_FILE_RANGE copy_file_range_compat

#include <io/copy_file_range-compat.c>

#endif

ssize_t

copy_file_range (int infd, __off64_t *pinoff,

                 int outfd, __off64_t *poutoff,

                 size_t length, unsigned int flags)

{

#ifdef __NR_copy_file_range

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

                                length, flags);

# ifndef __ASSUME_COPY_FILE_RANGE

  if (ret == -1 && errno == ENOSYS)

    ret = copy_file_range_compat (infd, pinoff, outfd, poutoff, length, flags);

# endif

  return ret;

#else  /* !__NR_copy_file_range */

  return copy_file_range_compat (infd, pinoff, outfd, poutoff, length, flags);

#endif

}