From: Jens Axboe <axboe@kernel.dk>
Date: Fri, 17 Jan 2020 18:15:34 +0000 (-0700)
Subject: io_uring: file switch work needs to get flushed on exit
X-Git-Tag: for-5.6/io_uring-vfs-2020-01-29~18
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e46a7950d362231a4d0b078af5f4c109b8e5ac9e;p=linux-block.git

io_uring: file switch work needs to get flushed on exit

We currently flush early, but if we have something in progress and a
new switch is scheduled, we need to ensure to flush after our teardown
as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 46cc1bc48062..a0a58c181eaf 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5089,11 +5089,14 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 		return -ENXIO;
 
 	/* protect against inflight atomic switch, which drops the ref */
-	flush_work(&data->ref_work);
 	percpu_ref_get(&data->refs);
+	/* wait for existing switches */
+	flush_work(&data->ref_work);
 	percpu_ref_kill_and_confirm(&data->refs, io_file_ref_kill);
 	wait_for_completion(&data->done);
 	percpu_ref_put(&data->refs);
+	/* flush potential new switch */
+	flush_work(&data->ref_work);
 	percpu_ref_exit(&data->refs);
 
 	__io_sqe_files_unregister(ctx);