From c93cc9e16d88e0f5ea95d2d65d58a8a4dab258bc Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Sat, 16 Jan 2021 11:52:11 -0700
Subject: [PATCH] io_uring: iopoll requests should also wake task ->in_idle
 state

If we're freeing/finishing iopoll requests, ensure we check if the task
is in idling in terms of cancelation. Otherwise we could end up waiting
forever in __io_uring_task_cancel() if the task has active iopoll
requests that need cancelation.

Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io_uring.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 985a9e3f976d3..5cda878b69cfd 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2270,6 +2270,8 @@ static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
 		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);
 		rb->task = NULL;
 	}
@@ -2288,6 +2290,8 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
 			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);
 		}
 		rb->task = req->task;
-- 
2.30.2