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>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 18a452ac81ccc10f2211dca2278c6f606a343bcd..14c5655c0434159845b2e4af58fe4fac9d34301c 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -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