change data after aio_write to file request

Question

Is it safe to change or free the buffer passed to aio_write for writing in a file. Or should i wait for the operation to finish? Does the function copy all the buffer content to the queue or just the reference to the data?

Answer 1

From man 7 aio:

he control block buffer and the buffer pointed to by aio_buf must not be changed while the I/O operation is in progress. These buffers must remain valid until the I/O operation completes.

So you must not touch the structure until you have been informed that the operation has completed.