Man page 9 : generic_file_aio_write

generic_file_aio_write - write data to a file

ssize_t generic_file_aio_write(struct kiocb *  iocb , const struct iovec *  iov , unsigned long  nr_segs , loff_t  pos );

iocb
    IO state structure

iov
    vector with data to write

nr_segs
    number of segments in the vector

pos
    position in file where to write

This is a wrapper around __generic_file_aio_write to be used by most filesystems. It takes care of syncing the file in case of O_SYNC file and acquires i_mutex as needed.