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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 F0A3BC433FF for ; Thu, 8 Aug 2019 23:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1ED1208C3 for ; Thu, 8 Aug 2019 23:51:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="Gfx81Rb5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404679AbfHHXvy (ORCPT ); Thu, 8 Aug 2019 19:51:54 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:44126 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732938AbfHHXvx (ORCPT ); Thu, 8 Aug 2019 19:51:53 -0400 Received: by mail-pf1-f195.google.com with SMTP id t16so44963455pfe.11 for ; Thu, 08 Aug 2019 16:51:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=p/G0TFVjCUap+pDH4HwBYaUgixwH7p+g48u4h0lUf/g=; b=Gfx81Rb5sKUjj0wNVhcQPEeBzwNfWHUUVfG0NTwMHkz6ASP2Usv3QvC3SUCcxyQJik Zr3PBpyTYptMyWO3cf4GZNvU+8n2qqfofWVWeriVHxoNflgz++9Zsai6R0Etb+Na54td O6Z3rsfOd+dQ7QbAqrU9OTAMbU4uszormzKog= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=p/G0TFVjCUap+pDH4HwBYaUgixwH7p+g48u4h0lUf/g=; b=a4E3ntxD48h3B7G37ojNPaR7eatrAavKvuj3K0KdhwoW55ROFJMtAWLTSarMtU5u1M P62I9kf+1nS+q6cO7jupdC+wQEj0pKIDTTokUTmRrPc6FiZO2jJp8sDukPhm3mIlgICl 11pYp6wGjGFxnIhEXxJL3HzfUvkNorq85Wn4xDMFdO3NIW6bJfBGc5wajPceXddjJnUY vpNw7SaA5X6TwMLGtEZy9VbVoXSXqfDaii6T8kORU2SsouBBEefR14YyppoYpHQ9vxUd sLHCDDt5JiwY7o3yodw/Lc7nHGlM9POLGuKhMtdh3BHq28AinFJaVGAowzigK3u5gcjL f3Rw== X-Gm-Message-State: APjAAAXY9+02bAT1yB/NcbGUNsKB/3Ejzjla4HrffjkEwGw0/Ndunn0d QQ4hBlj80E4POEgoDHgu0ItVFw== X-Google-Smtp-Source: APXvYqxrlsqV8xbl4fIYfzaen4LDYxS+vtSz93UK1MF6HsVtP1GEJoMKeg1vRzCNvxmwShtwIpGecQ== X-Received: by 2002:a17:90a:8d09:: with SMTP id c9mr6616809pjo.131.1565308313064; Thu, 08 Aug 2019 16:51:53 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id z13sm3647295pjn.32.2019.08.08.16.51.51 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 08 Aug 2019 16:51:52 -0700 (PDT) Date: Thu, 8 Aug 2019 19:51:50 -0400 From: Joel Fernandes To: Alessio Balsini Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@kernel.dk, dvander@gmail.com, elsk@google.com, gregkh@linuxfoundation.org, kernel-team@android.com Subject: Re: [PATCH v2] loop: Add LOOP_SET_DIRECT_IO to compat ioctl Message-ID: <20190808235150.GA208797@google.com> References: <20190807004828.28059-1-balsini@android.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190807004828.28059-1-balsini@android.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Aug 07, 2019 at 01:48:28AM +0100, Alessio Balsini wrote: > Enabling Direct I/O with loop devices helps reducing memory usage by > avoiding double caching. 32 bit applications running on 64 bits systems > are currently not able to request direct I/O because is missing from the > lo_compat_ioctl. > > This patch fixes the compatibility issue mentioned above by exporting > LOOP_SET_DIRECT_IO as additional lo_compat_ioctl() entry. > The input argument for this ioctl is a single long converted to a 1-bit > boolean, so compatibility is preserved. This commit message looks better now. thanks, - Joel > Cc: Jens Axboe > Signed-off-by: Alessio Balsini > --- > drivers/block/loop.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/block/loop.c b/drivers/block/loop.c > index 44c9985f352ab..2e2193f754ab0 100644 > --- a/drivers/block/loop.c > +++ b/drivers/block/loop.c > @@ -1753,6 +1753,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, > case LOOP_SET_FD: > case LOOP_CHANGE_FD: > case LOOP_SET_BLOCK_SIZE: > + case LOOP_SET_DIRECT_IO: > err = lo_ioctl(bdev, mode, cmd, arg); > break; > default: > -- > 2.23.0.rc1.153.gdeed80330f-goog >