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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B86C2C2D0CE for ; Tue, 21 Jan 2020 13:43:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 83F82217F4 for ; Tue, 21 Jan 2020 13:43:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GEhcFCQq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 83F82217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54034 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ittol-0007hy-4x for qemu-devel@archiver.kernel.org; Tue, 21 Jan 2020 08:43:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52817) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itsht-0003WS-O4 for qemu-devel@nongnu.org; Tue, 21 Jan 2020 07:32:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itshs-0004wa-Lk for qemu-devel@nongnu.org; Tue, 21 Jan 2020 07:32:33 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:27245 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1itshs-0004wM-Hx for qemu-devel@nongnu.org; Tue, 21 Jan 2020 07:32:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579609952; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JTpjZPadHNrcDZKv51V6CLKGvZ7oo/FweuUesYbxnBo=; b=GEhcFCQqJImsnsNcK4QDopz4MtGHF1TZwN27/vCFETzld0RR40uHb7z0pHlHrughRYKIE6 SqJyYfABqrEk8NhdZTkdmKHgAIEBDD/P78rqsT19g6E95ULBcZ3nbrp/vx2jlT+qdauc4g PYvRuPeqQCZVCRAp36LsVQHtMKPHT7k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-298-rMHCKgNHNhS0wpgAnik7nA-1; Tue, 21 Jan 2020 07:32:27 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AB2E58017CC; Tue, 21 Jan 2020 12:32:26 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.36.118.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id DFB0F60BE0; Tue, 21 Jan 2020 12:32:24 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, berrange@redhat.com, slp@redhat.com, philmd@redhat.com Subject: [PATCH v2 098/109] virtiofsd: Reset O_DIRECT flag during file open Date: Tue, 21 Jan 2020 12:24:22 +0000 Message-Id: <20200121122433.50803-99-dgilbert@redhat.com> In-Reply-To: <20200121122433.50803-1-dgilbert@redhat.com> References: <20200121122433.50803-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: rMHCKgNHNhS0wpgAnik7nA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: m.mizuma@jp.fujitsu.com, misono.tomohiro@jp.fujitsu.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vivek Goyal If an application wants to do direct IO and opens a file with O_DIRECT in guest, that does not necessarily mean that we need to bypass page cache on host as well. So reset this flag on host. If somebody needs to bypass page cache on host as well (and it is safe to do so), we can add a knob in daemon later to control this behavior. I check virtio-9p and they do reset O_DIRECT flag. Signed-off-by: Vivek Goyal Reviewed-by: Daniel P. Berrang=C3=A9 --- tools/virtiofsd/passthrough_ll.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index 4c3a48325f..cadfa676ca 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1721,6 +1721,13 @@ static void lo_create(fuse_req_t req, fuse_ino_t par= ent, const char *name, goto out; } =20 + /* + * O_DIRECT in guest should not necessarily mean bypassing page + * cache on host as well. If somebody needs that behavior, it + * probably should be a configuration knob in daemon. + */ + fi->flags &=3D ~O_DIRECT; + fd =3D openat(parent_inode->fd, name, (fi->flags | O_CREAT) & ~O_NOFOL= LOW, mode); err =3D fd =3D=3D -1 ? errno : 0; @@ -1950,6 +1957,13 @@ static void lo_open(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi) fi->flags &=3D ~O_APPEND; } =20 + /* + * O_DIRECT in guest should not necessarily mean bypassing page + * cache on host as well. If somebody needs that behavior, it + * probably should be a configuration knob in daemon. + */ + fi->flags &=3D ~O_DIRECT; + sprintf(buf, "%i", lo_fd(req, ino)); fd =3D openat(lo->proc_self_fd, buf, fi->flags & ~O_NOFOLLOW); if (fd =3D=3D -1) { --=20 2.24.1