From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [59.151.112.132] (helo=heian.cn.fujitsu.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZTlU2-0007gZ-HJ for linux-mtd@lists.infradead.org; Mon, 24 Aug 2015 06:43:55 +0000 Message-ID: <55DABBAC.9040401@cn.fujitsu.com> Date: Mon, 24 Aug 2015 14:37:32 +0800 From: Dongsheng Yang MIME-Version: 1.0 To: , , CC: Subject: Re: [PATCH] mkfs.ubifs: remove the check for UBIFS_MAX_LEB_SZ References: <1439873555-5352-1-git-send-email-yangds.fnst@cn.fujitsu.com> <1439887948.31419.118.camel@gmail.com> <55DA6E69.8070301@cn.fujitsu.com> <1440397943.15510.2.camel@gmail.com> In-Reply-To: <1440397943.15510.2.camel@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/24/2015 02:32 PM, Artem Bityutskiy wrote: > On Mon, 2015-08-24 at 09:07 +0800, Dongsheng Yang wrote: >> On 08/18/2015 04:52 PM, Artem Bityutskiy wrote: >>> On Tue, 2015-08-18 at 12:52 +0800, Dongsheng Yang wrote: >>>> There is a commit 92ed6c0 to increase UBIFS_MAX_LEB_SZ >>>> to 2MiB. But recently, as the leb size become larger and >>>> larger, 2MiB is not a suitable limit any more. >>>> >>>> Then remove this check in mkfs.ubifs >>>> >>>> Signed-off-by: Dongsheng Yang >>>> --- >>>> NOTE: >>>> I am not sure the reason why we have to >>>> limit the leb size in mkfs.ubifs. Because >>>> I did not find any reason for it, I send >>>> this patch out. It's very possible I am >>>> mising something. >>> >>> Well, this is sanity check for the user input. If you accidentally >>> added few zeroes, we want to spot this and inform you, and you may >>> appreciate that we did not just created a bugus image for you. >>> That's >>> the idea. >> >> Sorry, Artem, I was trying to understand it, but I did not got the >> point. Could you give me some more information about the idea? Maybe >> an example? > > Well, this is defensive programming concept. Ha, okey, got it. That's good. But I got a device with ped_size=32M. (Although that would affect ubi/ubifs performance negatively, that's another topic) I am not sure increasing the MAX_LEB_SIZE to 32M is a good idea, at least I don't think it's convincing to others that "I have a device with 32M peb, so I will increase it to 32M". Could you give me some more suggestion? Thanx > Something goes wrong, due > to bad user input and/or a bug we get to this place with an bogus size. > This check catches it and errors out versus we just go forward, > generate a bugus image, which you then flash and find that things do > not work, and then spend your time for further investigations. Nothing > more than that. > > Artem. > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/ >