FAILED: patch "[PATCH] io_uring: reinforce cancel on flush during exit" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3a7efd1ad269ccaf9c1423364d97c9661ba6dafa Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu, 28 Jan 2021 23:23:42 +0000
Subject: [PATCH] io_uring: reinforce cancel on flush during exit

What 84965ff8a84f0 ("io_uring: if we see flush on exit, cancel related tasks")
really wants is to cancel all relevant REQ_F_INFLIGHT requests reliably.
That can be achieved by io_uring_cancel_files(), but we'll miss it
calling io_uring_cancel_task_requests(files=NULL) from io_uring_flush(),
because it will go through __io_uring_cancel_task_requests().

Just always call io_uring_cancel_files() during cancel, it's good enough
for now.

Cc: stable@vger.kernel.org # 5.9+
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 12bf7180c0f1..38c6cbe1ab38 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8976,10 +8976,9 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 	io_cancel_defer_files(ctx, task, files);
 	io_cqring_overflow_flush(ctx, true, task, files);
 
+	io_uring_cancel_files(ctx, task, files);
 	if (!files)
 		__io_uring_cancel_task_requests(ctx, task);
-	else
-		io_uring_cancel_files(ctx, task, files);
 
 	if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
 		atomic_dec(&task->io_uring->in_idle);