[PATCHSET next 0/2] Allow MSG_WAITALL for send/sendmsg

[Jens Axboe <axboe@kernel.dk>]

Hi,

Just like we did for recv/recvmsg, allow MSG_WAITALL to mean that we want
to wait for all the requested data instead of doing a partial completion.

Patch 2 ensures that we can sanely use apoll multiple times, as long as
we're making progress on the IO. This is important to avoid punting to
io-wq if we can avoid it. The gate on already having polled is lifted
if we did transfer some data, which should avoid the initial worry of
why that place was in check - repeatedly non-block retrying and getting
-EAGAIN.

-- 
Jens Axboe