io_uring: deduplicate failing task_work_add

When io_req_task_work_add() fails, the request will be cancelled by
enqueueing via task_works of io-wq. Extract a function for that.

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 c3e0d62..90c3cad 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2171,6 +2171,16 @@ static int io_req_task_work_add(struct io_kiocb *req)
        return ret;
 }
 
+static void io_req_task_work_add_fallback(struct io_kiocb *req,
+                                         void (*cb)(struct callback_head *))
+{
+       struct task_struct *tsk = io_wq_get_task(req->ctx->io_wq);
+
+       init_task_work(&req->task_work, cb);
+       task_work_add(tsk, &req->task_work, TWA_NONE);
+       wake_up_process(tsk);
+}
+
 static void __io_req_task_cancel(struct io_kiocb *req, int error)
 {
        struct io_ring_ctx *ctx = req->ctx;
@@ -2225,14 +2235,8 @@ static void io_req_task_queue(struct io_kiocb *req)
        percpu_ref_get(&req->ctx->refs);
 
        ret = io_req_task_work_add(req);
-       if (unlikely(ret)) {
-               struct task_struct *tsk;
-
-               init_task_work(&req->task_work, io_req_task_cancel);
-               tsk = io_wq_get_task(req->ctx->io_wq);
-               task_work_add(tsk, &req->task_work, TWA_NONE);
-               wake_up_process(tsk);
-       }
+       if (unlikely(ret))
+               io_req_task_work_add_fallback(req, io_req_task_cancel);
 }
 
 static inline void io_queue_next(struct io_kiocb *req)
@@ -2350,13 +2354,8 @@ static void io_free_req_deferred(struct io_kiocb *req)
 
        init_task_work(&req->task_work, io_put_req_deferred_cb);
        ret = io_req_task_work_add(req);
-       if (unlikely(ret)) {
-               struct task_struct *tsk;
-
-               tsk = io_wq_get_task(req->ctx->io_wq);
-               task_work_add(tsk, &req->task_work, TWA_NONE);
-               wake_up_process(tsk);
-       }
+       if (unlikely(ret))
+               io_req_task_work_add_fallback(req, io_put_req_deferred_cb);
 }
 
 static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
@@ -3425,15 +3424,8 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
        /* submit ref gets dropped, acquire a new one */
        refcount_inc(&req->refs);
        ret = io_req_task_work_add(req);
-       if (unlikely(ret)) {
-               struct task_struct *tsk;
-
-               /* queue just for cancelation */
-               init_task_work(&req->task_work, io_req_task_cancel);
-               tsk = io_wq_get_task(req->ctx->io_wq);
-               task_work_add(tsk, &req->task_work, TWA_NONE);
-               wake_up_process(tsk);
-       }
+       if (unlikely(ret))
+               io_req_task_work_add_fallback(req, io_req_task_cancel);
        return 1;
 }
 
@@ -5153,12 +5145,8 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
         */
        ret = io_req_task_work_add(req);
        if (unlikely(ret)) {
-               struct task_struct *tsk;
-
                WRITE_ONCE(poll->canceled, true);
-               tsk = io_wq_get_task(req->ctx->io_wq);
-               task_work_add(tsk, &req->task_work, TWA_NONE);
-               wake_up_process(tsk);
+               io_req_task_work_add_fallback(req, func);
        }
        return 1;
 }