io_uring: kill io_wq_current_is_worker() in iopoll

Don't decide about locking based on io_wq_current_is_worker(), it's not
consistent with all other code and is expensive, use issue_flags.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7546d5a58efa4360173541c6fe02ee6b8c7b4ea7.1634314022.git.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 5a4d13a..348e587 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2713,13 +2713,13 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
  * find it from a io_do_iopoll() thread before the issuer is done
  * accessing the kiocb cookie.
  */
-static void io_iopoll_req_issued(struct io_kiocb *req)
+static void io_iopoll_req_issued(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_ring_ctx *ctx = req->ctx;
-       const bool in_async = io_wq_current_is_worker();
+       const bool need_lock = !(issue_flags & IO_URING_F_NONBLOCK);
 
        /* workqueue context doesn't hold uring_lock, grab it now */
-       if (unlikely(in_async))
+       if (unlikely(need_lock))
                mutex_lock(&ctx->uring_lock);
 
        /*
@@ -2747,7 +2747,7 @@ static void io_iopoll_req_issued(struct io_kiocb *req)
        else
                wq_list_add_tail(&req->comp_list, &ctx->iopoll_list);
 
-       if (unlikely(in_async)) {
+       if (unlikely(need_lock)) {
                /*
                 * If IORING_SETUP_SQPOLL is enabled, sqes are either handle
                 * in sq thread task context or in io worker task context. If
@@ -6715,7 +6715,7 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
                return ret;
        /* If the op doesn't have a file, we're not polling for it */
        if ((req->ctx->flags & IORING_SETUP_IOPOLL) && req->file)
-               io_iopoll_req_issued(req);
+               io_iopoll_req_issued(req, issue_flags);
 
        return 0;
 }