Do multiple io_uring_prep_send requests for the same socket need to be linked?

[andyg24]

For network data streaming, if I submit two send requests on the same socket, can I assume that the first request will always be sent first even if I don't use IOSQE_IO_LINK?

For correctness, it appears that MSG_WAITALL needs to be set in this case (otherwise a partial send can cause stream corruption). But it's not clear from the man page if IOSQE_IO_LINK is also necessary.

[andyg24]

Moved this to #1001