io_uring: consolidate putting reqs task

We grab a task for each request and while putting it it also have to do
extra work like inflight accounting and waking up that task. This
sequence is duplicated several time, it's good time to add a helper.
More to that, the helper generates better code due to better locality
and so not failing alias analysis.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -2023,17 +2023,22 @@ static void io_dismantle_req(struct io_kiocb *req)
 	io_req_clean_work(req);
 }
 
+static inline void io_put_task(struct task_struct *task, int nr)
+{
+	struct io_uring_task *tctx = task->io_uring;
+
+	percpu_counter_sub(&tctx->inflight, nr);
+	if (unlikely(atomic_read(&tctx->in_idle)))
+		wake_up(&tctx->wait);
+	put_task_struct_many(task, nr);
+}
+
 static void __io_free_req(struct io_kiocb *req)
 {
-	struct io_uring_task *tctx = req->task->io_uring;
 	struct io_ring_ctx *ctx = req->ctx;
 
 	io_dismantle_req(req);
-
-	percpu_counter_dec(&tctx->inflight);
-	if (atomic_read(&tctx->in_idle))
-		wake_up(&tctx->wait);
-	put_task_struct(req->task);
+	io_put_task(req->task, 1);
 
 	if (likely(!io_is_fallback_req(req)))
 		kmem_cache_free(req_cachep, req);
@@ -2287,12 +2292,7 @@ static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
 	if (rb->to_free)
 		__io_req_free_batch_flush(ctx, rb);
 	if (rb->task) {
-		struct io_uring_task *tctx = rb->task->io_uring;
-
-		percpu_counter_sub(&tctx->inflight, rb->task_refs);
-		if (atomic_read(&tctx->in_idle))
-			wake_up(&tctx->wait);
-		put_task_struct_many(rb->task, rb->task_refs);
+		io_put_task(rb->task, rb->task_refs);
 		rb->task = NULL;
 	}
 }
@@ -2306,14 +2306,8 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
 	io_queue_next(req);
 
 	if (req->task != rb->task) {
-		if (rb->task) {
-			struct io_uring_task *tctx = rb->task->io_uring;
-
-			percpu_counter_sub(&tctx->inflight, rb->task_refs);
-			if (atomic_read(&tctx->in_idle))
-				wake_up(&tctx->wait);
-			put_task_struct_many(rb->task, rb->task_refs);
-		}
+		if (rb->task)
+			io_put_task(rb->task, rb->task_refs);
 		rb->task = req->task;
 		rb->task_refs = 0;
 	}