Commit d1d681b0 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: optimise io_import_iovec fixed path 



Delay loading req->rw.{addr,len} in io_import_iovec until it's really
needed, so removing extra loads for the fixed path, which doesn't use
them.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3cc48dd0c4f1a37c4ce9aab5784281a2d83ad8be.1634314022.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9882131c

fs/io_uring.c

+6 −3
Original line number Diff line number Diff line
@@ -3159,9 +3159,9 @@ static int __io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, 
			     struct io_rw_state *s, unsigned int issue_flags)

{

	struct iov_iter *iter = &s->iter;

	void __user *buf = u64_to_user_ptr(req->rw.addr);

	size_t sqe_len = req->rw.len;

	u8 opcode = req->opcode;

	void __user *buf;

	size_t sqe_len;

	ssize_t ret;



	if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
@@ -3170,9 +3170,12 @@ static int __io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec, 
	}



	/* buffer index only valid with fixed read/write, or buffer select  */

	if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))

	if (unlikely(req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT)))

		return -EINVAL;



	buf = u64_to_user_ptr(req->rw.addr);

	sqe_len = req->rw.len;



	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {

		if (req->flags & REQ_F_BUFFER_SELECT) {

			buf = io_rw_buffer_select(req, &sqe_len, issue_flags);