Patch "io_uring: improve send/recv error handling" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    io_uring: improve send/recv error handling

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     io_uring-improve-send-recv-error-handling.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7ec39780241bf364da91b8ac8da42370c0ae0a0d
Author: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date:   Tue Nov 23 00:07:47 2021 +0000

    io_uring: improve send/recv error handling
    
    commit 7297ce3d59449de49d3c9e1f64ae25488750a1fc upstream.
    
    Hide all error handling under common if block, removes two extra ifs on
    the success path and keeps the handling more condensed.
    
    Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
    Link: https://lore.kernel.org/r/5761545158a12968f3caf30f747eea65ed75dfc1.1637524285.git.asml.silence@xxxxxxxxx
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index d855e668f37c..93023562d548 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -4866,17 +4866,18 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
 
 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
-	if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
-		return io_setup_async_msg(req, kmsg);
-	if (ret == -ERESTARTSYS)
-		ret = -EINTR;
 
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+			return io_setup_async_msg(req, kmsg);
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		req_set_fail(req);
+	}
 	/* fast path, check for non-NULL to avoid function call */
 	if (kmsg->free_iov)
 		kfree(kmsg->free_iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
-	if (ret < min_ret)
-		req_set_fail(req);
 	__io_req_complete(req, issue_flags, ret, 0);
 	return 0;
 }
@@ -4912,13 +4913,13 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags)
 
 	msg.msg_flags = flags;
 	ret = sock_sendmsg(sock, &msg);
-	if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
-		return -EAGAIN;
-	if (ret == -ERESTARTSYS)
-		ret = -EINTR;
-
-	if (ret < min_ret)
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+			return -EAGAIN;
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
 		req_set_fail(req);
+	}
 	__io_req_complete(req, issue_flags, ret, 0);
 	return 0;
 }
@@ -5105,10 +5106,15 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 
 	ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
 					kmsg->uaddr, flags);
-	if (force_nonblock && ret == -EAGAIN)
-		return io_setup_async_msg(req, kmsg);
-	if (ret == -ERESTARTSYS)
-		ret = -EINTR;
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && force_nonblock)
+			return io_setup_async_msg(req, kmsg);
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		req_set_fail(req);
+	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
+		req_set_fail(req);
+	}
 
 	if (req->flags & REQ_F_BUFFER_SELECTED)
 		cflags = io_put_recv_kbuf(req);
@@ -5116,8 +5122,6 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 	if (kmsg->free_iov)
 		kfree(kmsg->free_iov);
 	req->flags &= ~REQ_F_NEED_CLEANUP;
-	if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-		req_set_fail(req);
 	__io_req_complete(req, issue_flags, ret, cflags);
 	return 0;
 }
@@ -5164,15 +5168,18 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 		min_ret = iov_iter_count(&msg.msg_iter);
 
 	ret = sock_recvmsg(sock, &msg, flags);
-	if (force_nonblock && ret == -EAGAIN)
-		return -EAGAIN;
-	if (ret == -ERESTARTSYS)
-		ret = -EINTR;
 out_free:
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && force_nonblock)
+			return -EAGAIN;
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		req_set_fail(req);
+	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
+		req_set_fail(req);
+	}
 	if (req->flags & REQ_F_BUFFER_SELECTED)
 		cflags = io_put_recv_kbuf(req);
-	if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-		req_set_fail(req);
 	__io_req_complete(req, issue_flags, ret, cflags);
 	return 0;
 }