From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755914Ab2EGI6Q (ORCPT ); Mon, 7 May 2012 04:58:16 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:38120 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755580Ab2EGI6O (ORCPT ); Mon, 7 May 2012 04:58:14 -0400 Date: Mon, 7 May 2012 10:58:09 +0200 From: Ingo Molnar To: Sasha Levin Cc: torvalds@linux-foundation.org, chuck.lever@oracle.com, linux@razik.name, Trond.Myklebust@netapp.com, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu Subject: Re: [PATCH] init: don't try mounting device as nfs root unless type fully matches Message-ID: <20120507085809.GA23002@gmail.com> References: <1336230395-5215-1-git-send-email-levinsasha928@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1336230395-5215-1-git-send-email-levinsasha928@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Sasha Levin wrote: > Currently, we'll try mounting any device who's major device number is > UNNAMED_MAJOR as NFS root. This would happen for non-NFS devices as well (such > as 9p devices) but it wouldn't cause any issues since mounting the device > as NFS would fail quickly and the code proceeded to doing the proper mount: > > [ 101.522716] VFS: Unable to mount root fs via NFS, trying floppy. > [ 101.534499] VFS: Mounted root (9p filesystem) on device 0:18. > > Commit 6829a048 ("NFS: Retry mounting NFSROOT") has introduced retries when > mounting NFS root, which means that now we don't immediately fail and instead > it takes an additional 90+ seconds until we stop retrying, which has revealed > the issue this patch fixes. > > This meant that it would take an additional 90 seconds to boot when we're not > using a device type which gets detected in order before NFS. > > This patch modifies the NFS type check to require device type to be > 'Root_NFS' instead of requiring the device to have an UNNAMED_MAJOR major. > This makes boot process cleaner since we now won't go through the NFS mounting > code at all when the device isn't an NFS root ("/dev/nfs"). > > Signed-off-by: Sasha Levin > --- > init/do_mounts.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/init/do_mounts.c b/init/do_mounts.c > index 8dfa0de..d3f0aee 100644 > --- a/init/do_mounts.c > +++ b/init/do_mounts.c > @@ -482,7 +482,7 @@ void __init change_floppy(char *fmt, ...) > void __init mount_root(void) > { > #ifdef CONFIG_ROOT_NFS > - if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) { > + if (ROOT_DEV == Root_NFS) { > if (mount_nfs_root()) > return; Acked-by: Ingo Molnar This bug actively broke my KVM bootup, it gave the impression that the bootup was hung, while it was just retrying for a looong time. Thanks, Ingo