1  /* Linux implementation of pwritev2.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <sys/uio.h>
      20  #include <sysdep-cancel.h>
      21  
      22  #ifndef __OFF_T_MATCHES_OFF64_T
      23  
      24  ssize_t
      25  pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
      26  	  int flags)
      27  {
      28  
      29    ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
      30  				   LO_HI_LONG (offset), flags);
      31    if (result >= 0 || errno != ENOSYS)
      32      return result;
      33  
      34    /* Trying to emulate the pwritev2 syscall flags is troublesome:
      35  
      36       * We can not temporary change the file state of the O_DSYNC and O_SYNC
      37         flags to emulate RWF_{D}SYNC (attempts to change the state of using
      38         fcntl are silently ignored).
      39  
      40       * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
      41         semantic not provided by any other flag (O_NONBLOCK for instance).  */
      42  
      43    if (flags != 0)
      44      {
      45        __set_errno (ENOTSUP);
      46        return -1;
      47      }
      48    if (offset == -1)
      49      return __writev (fd, vector, count);
      50    else
      51      return pwritev (fd, vector, count, offset);
      52  }
      53  
      54  #endif