Pull io_uring fixes from Jens Axboe:
- A tweak to IOSQE_IO_LINK (also marked for stable) to allow links that
don't sever if the result is < 0.
This is mostly for linked timeouts, where if we ask for a pure
timeout we always get -ETIME. This makes links useless for that case,
hence allow a case where it works.
- Five minor optimizations to fix and improve cases that regressed
since v5.4.
- An SQTHREAD locking fix.
- A sendmsg/recvmsg iov assignment fix.
- Net fix where read_iter/write_iter don't honor IOCB_NOWAIT, and
subsequently ensuring that works for io_uring.
- Fix a case where for an invalid opcode we might return -EBADF instead
of -EINVAL, if the ->fd of that sqe was set to an invalid fd value.
* tag 'io_uring-5.5-
20191212' of git://git.kernel.dk/linux-block:
io_uring: ensure we return -EINVAL on unknown opcode
io_uring: add sockets to list of files that support non-blocking issue
net: make socket read/write_iter() honor IOCB_NOWAIT
io_uring: only hash regular files for async work execution
io_uring: run next sqe inline if possible
io_uring: don't dynamically allocate poll data
io_uring: deferred send/recvmsg should assign iov
io_uring: sqthread should grab ctx->uring_lock for submissions
io-wq: briefly spin for new work after finishing work
io-wq: remove worker->wait waitqueue
io_uring: allow unbreakable links