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=-6.8 required=3.0 tests=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 D50ACC43331 for ; Fri, 6 Sep 2019 10:03:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B64BF2084F for ; Fri, 6 Sep 2019 10:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389084AbfIFKDc (ORCPT ); Fri, 6 Sep 2019 06:03:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51162 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730500AbfIFKDb (ORCPT ); Fri, 6 Sep 2019 06:03:31 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B7A11315C010; Fri, 6 Sep 2019 10:03:31 +0000 (UTC) Received: from localhost (ovpn-117-208.ams2.redhat.com [10.36.117.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id A3BBC5C1D4; Fri, 6 Sep 2019 10:03:25 +0000 (UTC) From: Stefan Hajnoczi To: virtio-fs@redhat.com Cc: mszeredi@redhat.com, David Howells , Al Viro , linux-fsdevel@vger.kernel.org, Vivek Goyal , Stefan Hajnoczi Subject: [PATCH] init/do_mounts.c: add virtiofs root fs support Date: Fri, 6 Sep 2019 11:03:24 +0100 Message-Id: <20190906100324.8492-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Fri, 06 Sep 2019 10:03:31 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Make it possible to boot directly from a virtiofs file system with tag 'myfs' using the following kernel parameters: rootfstype=virtiofs root=myfs rw Booting directly from virtiofs makes it possible to use a directory on the host as the root file system. This is convenient for testing and situations where manipulating disk image files is cumbersome. Signed-off-by: Stefan Hajnoczi --- This patch is based on linux-next (next-20190904) but should apply cleanly to other virtiofs trees. init/do_mounts.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/init/do_mounts.c b/init/do_mounts.c index 9634ecf3743d..030be2f1999a 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -554,6 +554,16 @@ void __init mount_root(void) change_floppy("root floppy"); } #endif +#ifdef CONFIG_VIRTIO_FS + if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) { + if (!do_mount_root(root_device_name, "virtiofs", + root_mountflags, root_mount_data)) + return; + + panic("VFS: Unable to mount root fs \"%s\" from virtiofs", + root_device_name); + } +#endif #ifdef CONFIG_BLOCK { int err = create_dev("/dev/root", ROOT_DEV); -- 2.21.0