From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.233] helo=mgw-mx06.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.68 #1 (Red Hat Linux)) id 1Jy0Gn-0001Ev-4v for linux-mtd@lists.infradead.org; Mon, 19 May 2008 07:58:57 +0000 Subject: Re: ext2 for read-only file system on UBI From: Artem Bityutskiy To: Hamish Moffatt In-Reply-To: <1211183663.27243.32.camel@sauron> References: <20080519062149.GA16462@cloud.net.au> <1211179073.27243.22.camel@sauron> <20080519065623.GA17246@cloud.net.au> <1211180904.27243.27.camel@sauron> <20080519074403.GA17911@cloud.net.au> <1211183663.27243.32.camel@sauron> Content-Type: text/plain; charset=utf-8 Date: Mon, 19 May 2008 10:57:36 +0300 Message-Id: <1211183856.27243.35.camel@sauron> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Cc: linux-mtd@lists.infradead.org Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2008-05-19 at 10:54 +0300, Artem Bityutskiy wrote: > > Thanks for the links. So, read-write with mtdblock is dangerous > > (regardless of UBI) because it must erase and rewrite a whole block, > > right? >=20 > Yes, and you loose plenty of data in case of power-cuts. >=20 > > Proposed ubiblk (linked from above) would use UBI ops to make the > > update operation safe. >=20 > I have not looked that close at Nancy's patches because I did not like > her unreasonable copy-paste stuff. But I assume she would do something > like I proposed here: >=20 > http://lists.infradead.org/pipermail/linux-mtd/2008-January/020381.html Basically the idea is to implement something as straightforward as mtdblock, but using the "atomic LEB change" [1] operation and do not loose data in case of power-cuts. 1. http://www.linux-mtd.infradead.org/doc/ubi.html#L_lebchange --=20 Best regards, Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90= =D1=80=D1=82=D1=91=D0=BC)