From 3d200242a6c968af321913b635fc4014b238cba4 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 5 May 2022 21:47:55 -0600
Subject: [PATCH] io_uring: add buffer selection support to IORING_OP_NOP
Git-commit: 3d200242a6c968af321913b635fc4014b238cba4
Patch-mainline: v5.19-rc1
References: bsc#1205205
Obviously not really useful since it's not transferring data, but it
is helpful in benchmarking overhead of provided buffers.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
fs/io_uring.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1053,6 +1053,7 @@ struct io_op_def {
static const struct io_op_def io_op_defs[] = {
[IORING_OP_NOP] = {
.iopoll = 1,
+ .buffer_select = 1,
},
[IORING_OP_READV] = {
.needs_file = 1,
@@ -4514,7 +4515,17 @@ done:
*/
static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
{
- __io_req_complete(req, issue_flags, 0, 0);
+ void __user *buf;
+
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ size_t len = 1;
+
+ buf = io_buffer_select(req, &len, issue_flags);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ }
+
+ __io_req_complete(req, issue_flags, 0, io_put_kbuf(req, issue_flags));
return 0;
}