aio_fsync - Asynchronously writes changes in a file to permanent storage
int aio_fsync (
struct aiocb *aiocbp );
The aio_fsync function asynchronously causes system buffers containing a file's modified data to be written to permanent storage. All modified data in the file indicated by the file descriptor in the aio_fildes member of the aiocb structure referenced by the aiocbp argument is forced to the synchronized I/O completion state.
aio_fsync returns when the synchronization request has been initiated or queued, even when data cannot be synchronized immediately.
If op is O_DSYNC, all currently queued I/O operations are completed as if by a call to fdatasync. If op is O_SYNC, all currently queued I/O operations are completed as if by a call to fsync. If the aio_fsync function fails, outstanding I/O operations are not guaranteed to have been completed.
If aio_fsync succeeds, only the I/O that was queued at the time of the call is guaranteed to be synchronized; the completion of subsequent I/O is not guaranteed.
The aiocbp value may be used as an argument to the aio_error and aio_return functions to determine the error or return status 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 synchronized, the error status is set to reflect the success or failure of the operation. The aio_sigevent member of the aiocb structure defines the signal to be generated upon completion of the operation. If aio_sigevent.sigev_notify equals SIGEV_SIGNAL and aio_sigevent.sigev_signo is non-zero, a signal will be generated when all operations have achieved synchronized I/O completion.
Upon successful completion, the aio_fsync function returns a value of 0 (zero). If the aio_fsync function fails, a value of -1 is returned and errno is set to indicate the error. If aio_fsync fails, outstanding I/O operations are not guaranteed to have been completed.
If the aio_fsync function fails, errno may be set to one of the following values:
If any queued I/O operations fail, the aio_fsync function returns error conditions 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.
Functions: fdatasync(2), fcntl(2), fsync(2), open(2), read(2), sync(2), write(2) delim off