AIO_FSYNC(3P)                                       POSIX Programmer's Manual                                      AIO_FSYNC(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       aio_fsync - asynchronous file synchronization (REALTIME)

SYNOPSIS
       #include <aio.h>

       int aio_fsync(int op, struct aiocb *aiocbp);


DESCRIPTION
       The  aio_fsync()  function  shall  asynchronously force all I/O operations associated with the file indicated by the file
       descriptor aio_fildes member of the aiocb structure referenced by the aiocbp argument and queued at the time of the  call
       to  aio_fsync() to the synchronized I/O completion state. The function call shall return when the synchronization request
       has been initiated or queued to the file or device (even when the data cannot be synchronized immediately).

       If op is O_DSYNC, all currently queued I/O operations shall be completed as if by a call  to  fdatasync();  that  is,  as
       defined  for  synchronized  I/O  data integrity completion. If op is O_SYNC, all currently queued I/O operations shall be
       completed as if by a call to fsync(); that is, as  defined  for  synchronized  I/O  file  integrity  completion.  If  the
       aio_fsync()  function  fails, or if the operation queued by aio_fsync() fails, then, as for fsync() and fdatasync(), out-
       standing I/O operations are not guaranteed to have been completed.

       If aio_fsync() succeeds, then it is only the I/O that was queued at the time of the call to aio_fsync() that  is  guaran-
       teed  to be forced to the relevant completion state. The completion of subsequent I/O on the file descriptor is not guar-
       anteed to be completed in a synchronized fashion.

       The aiocbp argument refers to an asynchronous I/O control block.  The  aiocbp  value  may  be  used  as  an  argument  to
       aio_error()  and aio_return() in order to determine the error status and return status, respectively, of the asynchronous
       operation while it is proceeding. When the request is queued, the error status for the operation is [EINPROGRESS].   When
       all  data  has  been  successfully  transferred, the error status shall be reset to reflect the success or failure of the
       operation.  If the operation does not complete successfully, the error status for the operation shall be set to  indicate
       the  error.   The aio_sigevent member determines the asynchronous notification to occur as specified in Signal Generation
       and Delivery when all operations have achieved synchronized I/O completion. All other members of the structure referenced
       by  aiocbp  are  ignored.  If the control block referenced by aiocbp becomes an illegal address prior to asynchronous I/O
       completion, then the behavior is undefined.

       If the aio_fsync() function fails or aiocbp indicates an error condition, data is not guaranteed to  have  been  success-
       fully transferred.

RETURN VALUE
       The  aio_fsync()  function  shall  return the value 0 to the calling process if the I/O operation is successfully queued;
       otherwise, the function shall return the value -1 and set errno to indicate the error.

ERRORS
       The aio_fsync() function shall fail if:

       EAGAIN The requested asynchronous operation was not queued due to temporary resource limitations.

       EBADF  The aio_fildes member of the aiocb structure referenced by the aiocbp argument is not a valid file descriptor open
              for writing.

       EINVAL This implementation does not support synchronized I/O for this file.

       EINVAL A value of op other than O_DSYNC or O_SYNC was specified.


       In  the event that any of the queued I/O operations fail, aio_fsync() shall return the error condition defined for read()
       and write().  The error is returned in the error status for the asynchronous fsync() operation, which  can  be  retrieved
       using aio_error().

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       The aio_fsync() function is part of the Asynchronous Input and Output option and need not be available on all implementa-
       tions.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       fcntl(), fdatasync(), fsync(), open(), read(), write(), the Base Definitions volume of IEEE Std 1003.1-2001, <aio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                 AIO_FSYNC(3P)