| /* Linux implementation of preadv2. |
| 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 <sys/uio.h> |
| #include <sysdep-cancel.h> |
| |
| #ifndef __OFF_T_MATCHES_OFF64_T |
| |
| # if !defined (__NR_preadv2) && defined (__NR_pread64v2) |
| # define __NR_preadv2 __NR_pread64v2 |
| # endif |
| |
| ssize_t |
| preadv2 (int fd, const struct iovec *vector, int count, off_t offset, |
| int flags) |
| { |
| # ifdef __NR_preadv2 |
| ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count, |
| LO_HI_LONG (offset), flags); |
| if (result >= 0) |
| return result; |
| # endif |
| /* Trying to emulate the preadv2 syscall flags is troublesome: |
| |
| * We can not temporary change the file state of the O_DSYNC and O_SYNC |
| flags to emulate RWF_{D}SYNC (attempts to change the state of using |
| fcntl are silently ignored). |
| |
| * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal |
| semantic not provided by any other flag (O_NONBLOCK for instance). */ |
| |
| if (flags != 0) |
| { |
| __set_errno (ENOTSUP); |
| return -1; |
| } |
| return preadv (fd, vector, count, offset); |
| } |
| |
| #endif |
