io_uring: kill REQ_F_LINK_NEXT

After pulling nxt from a request, it's no more a links head, so clear
REQ_F_LINK_HEAD. Absence of this flag also indicates that there are no
linked requests, so replacing REQ_F_LINK_NEXT, which can be killed.

Linked timeouts also behave leaving the flag intact when necessary.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-06-28 12:52:34 +03:00 committed by Jens Axboe
parent 2d6500d44c
commit 9b0d911acc

View File

@ -526,7 +526,6 @@ enum {
REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
REQ_F_LINK_HEAD_BIT,
REQ_F_LINK_NEXT_BIT,
REQ_F_FAIL_LINK_BIT,
REQ_F_INFLIGHT_BIT,
REQ_F_CUR_POS_BIT,
@ -565,8 +564,6 @@ enum {
/* head of a link */
REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
/* already grabbed next link */
REQ_F_LINK_NEXT = BIT(REQ_F_LINK_NEXT_BIT),
/* fail rest of links */
REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
/* on inflight list */
@ -1559,10 +1556,6 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
struct io_ring_ctx *ctx = req->ctx;
bool wake_ev = false;
/* Already got next link */
if (req->flags & REQ_F_LINK_NEXT)
return;
/*
* The list should never be empty when we are called here. But could
* potentially happen if the chain is messed up, check to be on the
@ -1587,7 +1580,6 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
break;
}
req->flags |= REQ_F_LINK_NEXT;
if (wake_ev)
io_cqring_ev_posted(ctx);
}
@ -1628,6 +1620,7 @@ static void io_req_find_next(struct io_kiocb *req, struct io_kiocb **nxt)
{
if (likely(!(req->flags & REQ_F_LINK_HEAD)))
return;
req->flags &= ~REQ_F_LINK_HEAD;
/*
* If LINK is set, we have dependent requests in this chain. If we