Consolidate preadv/preadv64 implementation

[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / preadv.c

/* Copyright (C) 2009-2016 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 <sys/uio.h>
#include <sysdep-cancel.h>

#if __WORDSIZE != 64 || defined (__ASSUME_OFF_DIFF_OFF64)

# ifdef __ASSUME_PREADV

#  ifndef __NR_preadv
#   define __NR_preadv __NR_preadv64
#  endif

ssize_t
preadv (int fd, const struct iovec *vector, int count, off_t offset)
{
  return SYSCALL_CANCEL (preadv, fd, vector, count,
			 __ALIGNMENT_ARG SYSCALL_LL (offset));
}
# else
static ssize_t __atomic_preadv_replacement (int, const struct iovec *,
					    int, off_t) internal_function;
ssize_t
preadv (int fd, const struct iovec *vector, int count, off_t offset)
{
#  ifdef __NR_preadv
  ssize_t result = SYSCALL_CANCEL (preadv, fd, vector, count,
				   __ALIGNMENT_ARG SYSCALL_LL (offset));
  if (result >= 0 || errno != ENOSYS)
    return result;
#  endif
  return __atomic_preadv_replacement (fd, vector, count, offset);
}
#  define PREADV static internal_function __atomic_preadv_replacement
#  define PREAD __pread
#  define OFF_T off_t
#  include <sysdeps/posix/preadv.c>
# endif /* __ASSUME_PREADV  */
#endif