From f8e85cf255ad57d65eeb9a9d0e59e3dec55bdd9e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Sat, 23 Nov 2019 14:24:24 -0700
Subject: [PATCH] io_uring: add support for IORING_OP_CONNECT
This allows an application to call connect() in an async fashion. Like
other opcodes, we first try a non-blocking connect, then punt to async
context if we have to.
Note that we can still return -EINPROGRESS, and in that case the caller
should use IORING_OP_POLL_ADD to do an async wait for completion of the
connect request (just like for regular connect(2), except we can do it
async here too).
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 36 +++++++++++++++++++++++++++++++++++
include/uapi/linux/io_uring.h | 1 +
2 files changed, 37 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 129723087bad8..02254929231b3 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -550,6 +550,7 @@ static inline bool io_prep_async_work(struct io_kiocb *req,
case IORING_OP_RECVMSG:
case IORING_OP_ACCEPT:
case IORING_OP_POLL_ADD:
+ case IORING_OP_CONNECT:
/*
* We know REQ_F_ISREG is not set on some of these
* opcodes, but this enables us to keep the check in
@@ -1974,6 +1975,38 @@ static int io_accept(struct io_kiocb *req, const struct io_uring_sqe *sqe,
#endif
}
+static int io_connect(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+ struct io_kiocb **nxt, bool force_nonblock)
+{
+#if defined(CONFIG_NET)
+ struct sockaddr __user *addr;
+ unsigned file_flags;
+ int addr_len, ret;
+
+ if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
+ return -EINVAL;
+ if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags)
+ return -EINVAL;
+
+ addr = (struct sockaddr __user *) (unsigned long) READ_ONCE(sqe->addr);
+ addr_len = READ_ONCE(sqe->addr2);
+ file_flags = force_nonblock ? O_NONBLOCK : 0;
+
+ ret = __sys_connect_file(req->file, addr, addr_len, file_flags);
+ if (ret == -EAGAIN && force_nonblock)
+ return -EAGAIN;
+ if (ret == -ERESTARTSYS)
+ ret = -EINTR;
+ if (ret < 0 && (req->flags & REQ_F_LINK))
+ req->flags |= REQ_F_FAIL_LINK;
+ io_cqring_add_event(req, ret);
+ io_put_req_find_next(req, nxt);
+ return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
static inline void io_poll_remove_req(struct io_kiocb *req)
{
if (!RB_EMPTY_NODE(&req->rb_node)) {
@@ -2637,6 +2670,9 @@ static int io_issue_sqe(struct io_kiocb *req, struct io_kiocb **nxt,
case IORING_OP_ACCEPT:
ret = io_accept(req, s->sqe, nxt, force_nonblock);
break;
+ case IORING_OP_CONNECT:
+ ret = io_connect(req, s->sqe, nxt, force_nonblock);
+ break;
case IORING_OP_ASYNC_CANCEL:
ret = io_async_cancel(req, s->sqe, nxt);
break;
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 2a1569211d871..4637ed1d99496 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -73,6 +73,7 @@ struct io_uring_sqe {
#define IORING_OP_ACCEPT 13
#define IORING_OP_ASYNC_CANCEL 14
#define IORING_OP_LINK_TIMEOUT 15
+#define IORING_OP_CONNECT 16
/*
* sqe->fsync_flags
--
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