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



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       aio_fsync -- asynchronous file synchronization

SSYYNNOOPPSSIISS
       #include <aio.h>

       int aio_fsync(int _o_p, struct aiocb *_a_i_o_c_b_p);

DDEESSCCRRIIPPTTIIOONN
       The _a_i_o___f_s_y_n_c() function shall asynchronously perform a file
       synchronization operation, as specified by the _o_p argument, for I/O
       operations associated with the file indicated by the file descriptor
       _a_i_o___f_i_l_d_e_s member of the aaiiooccbb structure referenced by the _a_i_o_c_b_p
       argument and queued at the time of the call to _a_i_o___f_s_y_n_c().  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 _o_p is O_DSYNC, all currently queued I/O operations shall be
       completed as if by a call to _f_d_a_t_a_s_y_n_c(); that is, as defined for
       synchronized I/O data integrity completion.

       If _o_p is O_SYNC, all currently queued I/O operations shall be completed
       as if by a call to _f_s_y_n_c(); that is, as defined for synchronized I/O
       file integrity completion.  If the _a_i_o___f_s_y_n_c() function fails, or if
       the operation queued by _a_i_o___f_s_y_n_c() fails, then outstanding I/O
       operations are not guaranteed to have been completed.

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

       The _a_i_o_c_b_p argument refers to an asynchronous I/O control block. The
       _a_i_o_c_b_p value may be used as an argument to _a_i_o___e_r_r_o_r() and _a_i_o___r_e_t_u_r_n()
       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 [[EEIINNPPRROOGGRREESSSS]].  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 _a_i_o___s_i_g_e_v_e_n_t member
       determines the asynchronous notification to occur as specified in
       _S_e_c_t_i_o_n _2_._4_._1, _S_i_g_n_a_l _G_e_n_e_r_a_t_i_o_n _a_n_d _D_e_l_i_v_e_r_y when all operations have
       achieved synchronized I/O completion. All other members of the
       structure referenced by _a_i_o_c_b_p are ignored. If the control block
       referenced by _a_i_o_c_b_p becomes an illegal address prior to asynchronous
       I/O completion, then the behavior is undefined.

       If the _a_i_o___f_s_y_n_c() function fails or _a_i_o_c_b_p indicates an error
       condition, data is not guaranteed to have been successfully
       transferred.

RREETTUURRNN VVAALLUUEE
       The _a_i_o___f_s_y_n_c() function shall return the value 0 if the I/O operation
       is successfully queued; otherwise, the function shall return the value
       -1 and set _e_r_r_n_o to indicate the error.

EERRRROORRSS
       The _a_i_o___f_s_y_n_c() function shall fail if:

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

       EEBBAADDFF  The _a_i_o___f_i_l_d_e_s member of the aaiiooccbb structure referenced by the
              _a_i_o_c_b_p argument is not a valid file descriptor.

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

       EEIINNVVAALL The _a_i_o___f_i_l_d_e_s member of the aaiiooccbb structure refers to a file on
              which an _f_s_y_n_c() operation is not possible.

       EEIINNVVAALL A value of _o_p other than O_DSYNC or O_SYNC was specified, or
              O_DSYNC was specified and the implementation does not provide
              runtime support for the Synchronized Input and Output option, or
              O_SYNC was specified and the implementation does not provide
              runtime support for the File Synchronization option.

       In the event that any of the queued I/O operations fail, _a_i_o___f_s_y_n_c()
       shall return the error condition defined for _r_e_a_d() and _w_r_i_t_e().  The
       error is returned in the error status for the asynchronous operation,
       which can be retrieved using _a_i_o___e_r_r_o_r().

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       Note that even if the file descriptor is not open for writing, if there
       are any pending write requests on the underlying file, then that I/O
       will be completed prior to the return of a call to _a_i_o___e_r_r_o_r() or
       _a_i_o___r_e_t_u_r_n() indicating that the operation has completed.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _a_i_o___e_r_r_o_r(), _a_i_o___r_e_t_u_r_n(), _f_c_n_t_l(), _f_d_a_t_a_s_y_n_c(), _f_s_y_n_c(), _o_p_e_n(),
       _r_e_a_d(), _w_r_i_t_e()

       The Base Definitions volume of POSIX.1-2017, <<aaiioo..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                         AIO_FSYNC(3)
