From patchwork Fri Nov 20 14:59:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 1403756 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.a=rsa-sha256 header.s=20150623 header.b=s089ZVTl; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Cd08T37Szz9sSs for ; Sat, 21 Nov 2020 02:00:09 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727784AbgKTO7s (ORCPT ); Fri, 20 Nov 2020 09:59:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727123AbgKTO7r (ORCPT ); Fri, 20 Nov 2020 09:59:47 -0500 Received: from mail-il1-x143.google.com (mail-il1-x143.google.com [IPv6:2607:f8b0:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E107C0613CF for ; Fri, 20 Nov 2020 06:59:47 -0800 (PST) Received: by mail-il1-x143.google.com with SMTP id l12so8811570ilo.1 for ; Fri, 20 Nov 2020 06:59:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=0ev+vtzonlnX+q8/r8hhN7SdhSoYclUfgw0xLdzqzs8=; b=s089ZVTln1bL2Ghw1mB32NFy7WofNDkegNU8GNk2a5CyErzy5WOCIp8xB89MKiFZsz u8HzqYjh4+FsusRJnaOUuRLfoRssYC9B0OadcxvLvKFVwM0ps1nJ1hDSX/mU4pPvYdFm hvtObHQaSpW4Jv16kHo7Gkef4BWQtk30+WTIe8GWJlswsO0GiNluz/cz8CkmEQmIf97E LMySDDwh3WgKa/HRAtALxQn0Hm2SZCBvTEAs5vBQtm4JwAp79FOPDl9tLyhiigLVlEc7 GgoKj/Ig2/OjS0/EySnxftLtKXO7I0DOrI8O5BTNbNbqjT+ghW4AplkOdXP2Nl5HgIOJ 7SiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=0ev+vtzonlnX+q8/r8hhN7SdhSoYclUfgw0xLdzqzs8=; b=heNXJfba0b1uFLCf9IJM5/83uDKfc1FM5NxNnOxGUUA+MB4JkDhKJVdT0UuqLBvBpo EFeJom7T3sC+DWyMqYr5tPk20O3qYXzrB6YNdpBjPz3+b1L9QxTcWqL8KPCDGkS05Z5Q ta0wcgM8/89qe0Pt/UHm+I7cVEwG+JsP1GUUdz4GAiAAFUrn61XQcfKFbg3W/qxX3Kg8 C3y0cd0DuP2VjaEWQz0WVMhoTPRAdLb/SRSLOLy5ZXXTOCAqH8B6qGBrx53AuPUOzuL6 V0Pqxuw0F1dlWFHOYdib0vYP+5RhqjQ2kELbG91CeMGLqsnCE8EGQbVfcqtW3iNFi6Pe iPfw== X-Gm-Message-State: AOAM532uJJ+7EgH0U7GB6HiNKauQv/9vT0020UZaq/mQI3VzN8t0LWZ0 rs8RlCQSEnuRbf2xZAxxFIofk7EO5/+p3w== X-Google-Smtp-Source: ABdhPJwGU2CBL0nh+81lm+/RM3SLhazj1i9uNIHL2mhV9IyyusQSTXfpsErU+4CfkkzIwF/dtfMJ6g== X-Received: by 2002:a92:50e:: with SMTP id q14mr9433091ile.306.1605884386602; Fri, 20 Nov 2020 06:59:46 -0800 (PST) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id x5sm2057933ilc.15.2020.11.20.06.59.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 Nov 2020 06:59:45 -0800 (PST) To: Networking Cc: Jakub Kicinski From: Jens Axboe Subject: [PATCH] tun: honor IOCB_NOWAIT flag Message-ID: Date: Fri, 20 Nov 2020 07:59:45 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org tun only checks the file O_NONBLOCK flag, but it should also be checking the iocb IOCB_NOWAIT flag. Any fops using ->read/write_iter() should check both, otherwise it breaks users that correctly expect O_NONBLOCK semantics if IOCB_NOWAIT is set. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe --- Had a bug report on io_uring, and it's due to tun not honoring IOCB_NOWAIT. Let's get this fixed. diff --git a/drivers/net/tun.c b/drivers/net/tun.c index be69d272052f..cd06cae76035 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1961,12 +1961,15 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from) struct tun_file *tfile = file->private_data; struct tun_struct *tun = tun_get(tfile); ssize_t result; + int noblock = 0; if (!tun) return -EBADFD; - result = tun_get_user(tun, tfile, NULL, from, - file->f_flags & O_NONBLOCK, false); + if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) + noblock = 1; + + result = tun_get_user(tun, tfile, NULL, from, noblock, false); tun_put(tun); return result; @@ -2185,10 +2188,15 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) struct tun_file *tfile = file->private_data; struct tun_struct *tun = tun_get(tfile); ssize_t len = iov_iter_count(to), ret; + int noblock = 0; if (!tun) return -EBADFD; - ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL); + + if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) + noblock = 1; + + ret = tun_do_read(tun, tfile, to, noblock, NULL); ret = min_t(ssize_t, ret, len); if (ret > 0) iocb->ki_pos = ret;