From: Toshiyuki Okajima Subject: Re: [PATCH 3/3][RFC](Repost) ext4: add a message in remount/umount for ext4 Date: Thu, 01 Oct 2009 12:20:17 +0900 Message-ID: <4AC41FF1.7060703@jp.fujitsu.com> References: <20090930154931.ef2a4760.toshi.okajima@jp.fujitsu.com> <20090930172220.GL24383@mit.edu> Reply-To: toshi.okajima@jp.fujitsu.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: akpm@linux-foundation.org, adilger@sun.com, sandeen@redhat.com, linux-ext4@vger.kernel.org To: Theodore Tso Return-path: Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:43499 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752914AbZJADUU (ORCPT ); Wed, 30 Sep 2009 23:20:20 -0400 Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n913KMYW017882 for (envelope-from toshi.okajima@jp.fujitsu.com); Thu, 1 Oct 2009 12:20:22 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id B5E4E45DE51 for ; Thu, 1 Oct 2009 12:20:22 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 521E845DE4F for ; Thu, 1 Oct 2009 12:20:22 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 20A52E38006 for ; Thu, 1 Oct 2009 12:20:22 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 722831DB8040 for ; Thu, 1 Oct 2009 12:20:21 +0900 (JST) In-Reply-To: <20090930172220.GL24383@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Ted, thank you for your comment. Theodore Tso wrote: > On Wed, Sep 30, 2009 at 03:49:31PM +0900, Toshiyuki Okajima wrote: > > > From: Toshiyuki Okajima > > > > > > ext4 doesn't log a record of having unmounted the filesystem. And ext4 doesn't > > > log a record when the filesystem is remounted also with read-only. Therefore > > > in the system log, we cannot judge whether or not at the certain time this > > > filesystem user touches it. > > > For enterprise users, they often want to know when a certain filesystem is > > > mounted/remounted/unmounted. > > > > > > So, we output the message to the system log when the filesystem is > > > remounted/unmounted. > > > > > > Signed-off-by: Toshiyuki Okajima > > The question of whether this should be at the VFS layer is still an > open one, I think. It is true that ext3 and ext4 does print some I am recognizing it. But I think I have already explained its answer as follows: - A print mechanism has already been included at mount time. - The umount operation is opposite "mount operation". Therefore I think it is no problem that we add the print mechanism at the umount time. > filesystem specific information, but that could be handled via a new > method function in struct super_ops: > > mount_msg(struct super *sb, char *buf, int buflen) > However, I have noticed that the purpose of ext3/ext4 messages at mount time is for specific information but not for a general purpose by this comment. So, I think I should rearrange this feature into the VFS layer. I try to reimplement it later. Thanks, Toshiyuki Okajima