linux-kernel - [PATCH for-next 4/8] io_uring: recycle buffers on error

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Date:   Tue, 28 Jun 2022 08:02:24 -0700
From:   Dylan Yudaken <dylany@...com>
To:     Jens Axboe <axboe@...nel.dk>,
        Pavel Begunkov <asml.silence@...il.com>,
        <io-uring@...r.kernel.org>
CC:     <Kernel-team@...com>, <linux-kernel@...r.kernel.org>,
        Dylan Yudaken <dylany@...com>
Subject: [PATCH for-next 4/8] io_uring: recycle buffers on error

Rather than passing an error back to the user with a buffer attached,
recycle the buffer immediately.

Signed-off-by: Dylan Yudaken <dylany@...com>
---
 io_uring/net.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 5e84f7ab92a3..0268c4603f5d 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -481,10 +481,13 @@ 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 >= 0)
+	if (ret > 0)
 		ret += sr->done_io;
 	else if (sr->done_io)
 		ret = sr->done_io;
+	else
+		io_kbuf_recycle(req, issue_flags);
+
 	cflags = io_put_kbuf(req, issue_flags);
 	if (kmsg->msg.msg_inq)
 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
@@ -557,10 +560,13 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 		req_set_fail(req);
 	}
 
-	if (ret >= 0)
+	if (ret > 0)
 		ret += sr->done_io;
 	else if (sr->done_io)
 		ret = sr->done_io;
+	else
+		io_kbuf_recycle(req, issue_flags);
+
 	cflags = io_put_kbuf(req, issue_flags);
 	if (msg.msg_inq)
 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
-- 
2.30.2