Commit 1dbd023e authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: eliminate the need to track provided buffer ID separately 



We have io_kiocb->buf_index which is used for either fixed buffers, or
for provided buffers. For the latter, it's used to hold the buffer group
ID for buffer selection. Post selection, req->kbuf->bid is used to get
the buffer ID.

Store the buffer ID, when selected, in req->buf_index. If we do end up
recycling the buffer, reset it back to the buffer group ID.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 660cbfa2

fs/io_uring.c

+10 −6
Original line number Diff line number Diff line
@@ -951,6 +951,11 @@ struct io_kiocb { 
	u8				opcode;

	/* polled IO has completed */

	u8				iopoll_completed;

	/*

	 * Can be either a fixed buffer index, or used with provided buffers.

	 * For the latter, before issue it points to the buffer group ID,

	 * and after selection it points to the buffer ID itself.

	 */

	u16				buf_index;

	unsigned int			flags;
@@ -1456,14 +1461,11 @@ static inline void io_req_set_rsrc_node(struct io_kiocb *req, 


static unsigned int __io_put_kbuf(struct io_kiocb *req, struct list_head *list)

{

	struct io_buffer *kbuf = req->kbuf;

	unsigned int cflags;



	cflags = IORING_CQE_F_BUFFER | (kbuf->bid << IORING_CQE_BUFFER_SHIFT);

	req->flags &= ~REQ_F_BUFFER_SELECTED;

	list_add(&kbuf->list, list);

	list_add(&req->kbuf->list, list);

	req->kbuf = NULL;

	return cflags;



	return IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT);

}



static inline unsigned int io_put_kbuf_comp(struct io_kiocb *req)
@@ -1537,6 +1539,7 @@ static void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags) 
	bl = io_buffer_get_list(ctx, buf->bgid);

	list_add(&buf->list, &bl->buf_list);

	req->flags &= ~REQ_F_BUFFER_SELECTED;

	req->buf_index = buf->bgid;

	req->kbuf = NULL;



	io_ring_submit_unlock(ctx, issue_flags);
@@ -3469,6 +3472,7 @@ static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len, 
		*len = kbuf->len;

	req->flags |= REQ_F_BUFFER_SELECTED;

	req->kbuf = kbuf;

	req->buf_index = kbuf->bid;

	io_ring_submit_unlock(req->ctx, issue_flags);

	return u64_to_user_ptr(kbuf->addr);

}