io_uring: drop mm/files between task_work_submit

isilence · axboe · commit aec18a57edad · 2021-02-04T12:42:58.000-07:00
Since SQPOLL task can be shared and so task_work entries can be a mix of
them, we need to drop mm and files before trying to issue next request.

Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Pavel Begunkov &lt;asml.silence@gmail.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
diff --git a/fs/io_uring.c b/fs/io_uring.c
@@ -2205,6 +2205,9 @@ static void __io_req_task_submit(struct io_kiocb *req)
 	else
 		__io_req_task_cancel(req, -EFAULT);
 	mutex_unlock(&ctx->uring_lock);
+
+	if (ctx->flags & IORING_SETUP_SQPOLL)
+		io_sq_thread_drop_mm_files();
 }
 
 static void io_req_task_submit(struct callback_head *cb)

Original file line number	Diff line number	Diff line change
`@@ -2205,6 +2205,9 @@ static void __io_req_task_submit(struct io_kiocb *req)`
`2205`	`2205`	`else`
`2206`	`2206`	`__io_req_task_cancel(req, -EFAULT);`
`2207`	`2207`	`mutex_unlock(&ctx->uring_lock);`
	`2208`	`+`
	`2209`	`+ if (ctx->flags & IORING_SETUP_SQPOLL)`
	`2210`	`+ io_sq_thread_drop_mm_files();`
`2208`	`2211`	`}`
`2209`	`2212`
`2210`	`2213`	`static void io_req_task_submit(struct callback_head *cb)`