From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA163C11F6B for ; Mon, 12 Jul 2021 06:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EE216121E for ; Mon, 12 Jul 2021 06:52:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238545AbhGLGz1 (ORCPT ); Mon, 12 Jul 2021 02:55:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:54292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241134AbhGLGym (ORCPT ); Mon, 12 Jul 2021 02:54:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0ED86610D0; Mon, 12 Jul 2021 06:51:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626072711; bh=JBqtJSPvvQkU5ow888eMSxCthrpcA4MOjJr5pyJ/DP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ROeM6Di+hRpHrtXtpxh1LettGJKtEfZEwoVV/eJ0PYMacWzsWFniAMXM8Sx11lz0e T/SDqEhADffLnM9N6rU2yOSekXsyz+g3kDjss3+s768Wjws3/7l0fulM/SJmoB6mn1 +9hfMY9g/i+CJRlAY08/RpbhyVP+eQrle742Yc+I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Birk Hirdman , Pavel Begunkov , Jens Axboe Subject: [PATCH 5.10 589/593] io_uring: fix blocking inline submission Date: Mon, 12 Jul 2021 08:12:29 +0200 Message-Id: <20210712061000.401820859@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060843.180606720@linuxfoundation.org> References: <20210712060843.180606720@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pavel Begunkov commit 976517f162a05f4315b2373fd11585c395506259 upstream. There is a complaint against sys_io_uring_enter() blocking if it submits stdin reads. The problem is in __io_file_supports_async(), which sees that it's a cdev and allows it to be processed inline. Punt char devices using generic rules of io_file_supports_async(), including checking for presence of *_iter() versions of rw callbacks. Apparently, it will affect most of cdevs with some exceptions like null and zero devices. Cc: stable@vger.kernel.org Reported-by: Birk Hirdman Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/d60270856b8a4560a639ef5f76e55eb563633599.1623236455.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2770,7 +2770,7 @@ static bool io_file_supports_async(struc return true; return false; } - if (S_ISCHR(mode) || S_ISSOCK(mode)) + if (S_ISSOCK(mode)) return true; if (S_ISREG(mode)) { if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&