From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH 1/3] mmc: skip detection of nonremovable cards on rescan - card removal detection regression Date: Fri, 04 Mar 2011 14:25:30 +0900 Message-ID: <4D7077CA.3090307@samsung.com> References: <1290921690-6133-1-git-send-email-ohad@wizery.com> <1290921690-6133-2-git-send-email-ohad@wizery.com> <20101217005123.GD17239@void.printf.net> <1299205366.4999.3.camel@maxim-laptop> <1299207177.4999.10.camel@maxim-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7BIT Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:24408 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750740Ab1CDFZc (ORCPT ); Fri, 4 Mar 2011 00:25:32 -0500 Received: from epmmp2 (mailout3.samsung.com [203.254.224.33]) by mailout3.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LHI00EMLPQI1E20@mailout3.samsung.com> for linux-mmc@vger.kernel.org; Fri, 04 Mar 2011 14:25:30 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LHI001FJPQI4Z@mmp2.samsung.com> for linux-mmc@vger.kernel.org; Fri, 04 Mar 2011 14:25:30 +0900 (KST) In-reply-to: <1299207177.4999.10.camel@maxim-laptop> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Maxim Levitsky Cc: Chris Ball , Ohad Ben-Cohen , linux-mmc@vger.kernel.org Hi.. I agreed Chris's opinion..If use CONFIG_MMC_UNSAFE_RESUME, you can know to occur some problem..so mentions to "DANGEROUS" If card can be removed during suspend, i think we have too many cases. So this configuration...i think good that use only non-removable card. If you considered every case, you should not use UNSAFE_RESUME.. Regards, Jaehoon Chung Maxim Levitsky wrote: > On Thu, 2011-03-03 at 21:28 -0500, Chris Ball wrote: >> Hi, >> >> On Thu, Mar 03 2011, Maxim Levitsky wrote: >>> This patch breaks the CONFIG_MMC_UNSAFE_RESUME, because it sets fake >>> non-removeable flag, but the intended use of this option is to assume >>> that card is not removed _during_ suspend, and it can still be removed >>> during normal use. >>> With this commit, card removal isn't detected. >> I guess we disagree about the semantics of CONFIG_MMC_UNSAFE_RESUME. >> The Kconfig text says: >> >> config MMC_UNSAFE_RESUME >> bool "Assume MMC/SD cards are non-removable (DANGEROUS)" >> >> which I interpret as meaning that you should set MMC_UNSAFE_RESUME >> *if you're using a card that cannot be removed*. If your card *can* be >> removed, then it would be extremely foolish to turn on MMC_UNSAFE_RESUME, >> because then if someone removed your removable card during suspend and >> modified it in another machine before resuming, you'd get massive >> filesystem corruption. > That is assuming that someone kindly inserted the card back, while > system still was suspended, which is really unlikely, and besides, I > know who uses my computer (me mostly) and I know what I am doing. > > > The description also says: > > "If you say Y here, the MMC layer will assume that all cards > stayed in their respective slots during the suspend. The > normal behaviour is to remove them at suspend and > redetecting them at resume. Breaking this assumption will > in most cases result in data corruption." > > > I own my computer, and I don't need the OS to take the decisions for me. > > I don't want to have FS corruption if I accidentally suspend the system > with the card in the slot which could happen if that option is disabled. > > > Best regards, > Maxim Levitsky > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >