From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Lovenberg Subject: Re: "Write once only but read many" filesystem Date: Mon, 24 Mar 2008 00:49:17 -0400 Message-ID: <47E732CD.3070202@gmail.com> References: <804dabb00803140917o2abebd2dh12c77b21a48094c4@mail.gmail.com> <20080314232403.GI3542@webber.adilger.int> <47E48D84.7070701@gmail.com> <20080322102331.GA19347@logfs.org> <804dabb00803220752h670757d8o9c1b7fa3696467bc@mail.gmail.com> <20080322150626.GB19347@logfs.org> <804dabb00803220855q1aa41fc7mc30c7ce7951fe98@mail.gmail.com> <20080322165906.GC19347@logfs.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Peter Teoh , kernelnewbies , linux-fsdevel@vger.kernel.org, ext3-users@redhat.com To: =?UTF-8?B?SsO2cm4gRW5nZWw=?= Return-path: Received: from hs-out-0708.google.com ([64.233.178.240]:53155 "EHLO hs-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751215AbYCXEpU (ORCPT ); Mon, 24 Mar 2008 00:45:20 -0400 Received: by hs-out-0708.google.com with SMTP id 4so2064436hsl.5 for ; Sun, 23 Mar 2008 21:45:20 -0700 (PDT) In-Reply-To: <20080322165906.GC19347@logfs.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: J=C3=B6rn Engel wrote: > On Sat, 22 March 2008 23:55:53 +0800, Peter Teoh wrote: >>> Or do you want individual files/directories to be immutable - cha= ttr? >> chattr is not good enough, as root can still modify it. So if >> current feature is not there, then some small development may be >> needed. >> >>> And in either case, what problem do you want to solve with a read-= only filesystem? >> Simple: i want to record down everything that a user does, or a >> database does, or any applications running - just record down its >> state permanently securely into the filesystem, knowing that for sur= e, >> there is not way to modify the data, short of recreating the >> filesystem again. Sound logical? Or is there any loophole in th= is >> concept? >=20 > The loophole is called root. In a normal setup, root can do anything= , > including writing directly to the device your filesystem resides in, > writing to kernel memory, etc. >=20 > It may be rather inconvenient to change a filesystem by writing to th= e > block device, but far from impossible. If you want to make such chan= ges > impossible, you are facing an uphill battle that I personally don't c= are > about. And if inconvenience is good enough, wouldn't chattr be > sufficiently inconvenient? >=20 > J=C3=B6rn >=20 How about mounting an isofs via loopback? This has the added benefit o= f=20 being ready to be exported to disc. You can make it with mkisofs on a=20 directory structure and mount it to the tree with a normal mount(1). I= f=20 it asks for fs type on mount, I think its 'iso9660'. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html