From: Chris Ball Subject: Re: [PATCH] mke2fs: restore verbose message for BLKDISCARD Date: Fri, 08 Mar 2013 15:12:11 -0500 Message-ID: <87r4jpzm5g.fsf@octavius.laptop.org> References: <1362515118-30344-1-git-send-email-swarren@wwwdotorg.org> <5138EEBD.5000705@wwwdotorg.org> <513A1D56.1010402@wwwdotorg.org> <20130308190019.GB12008@thunk.org> <87vc91zp45.fsf@octavius.laptop.org> <513A441D.1060706@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Theodore Ts'o , =?utf-8?B?THVrw6HFoQ==?= Czerner , linux-ext4@vger.kernel.org, Stephen Warren To: Stephen Warren Return-path: Received: from void.printf.net ([89.145.121.20]:56585 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136Ab3CHUMT (ORCPT ); Fri, 8 Mar 2013 15:12:19 -0500 In-Reply-To: <513A441D.1060706@wwwdotorg.org> (Stephen Warren's message of "Fri, 08 Mar 2013 13:03:41 -0700") Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, On Fri, Mar 08 2013, Stephen Warren wrote: >> On Fri, Mar 08 2013, Theodore Ts'o wrote: >>> I hate to suggest this, but there's so many crappy devices out there >>> that I'm wondering if we need to figure out some way of maintaining a >>> black list of devices that don't handle discard properly. >> >> Yes, we already do that in the MMC layer. See e.g.: >> >> http://git.kernel.org/cgit/linux/kernel/git/cjb/mmc.git/commit/?id=3550ccdb9d8d350e526b809bf3dd92b550a74fe1 >> ("mmc: card: Skip secure erase on MoviNAND; causes unrecoverable corruption.") > > Unrecoverable sounds scary. Does that just mean data corruption, or a > permanently broken device? mk2e2fs -K followed by e2fsck and mounting > luckily seems to still work OK for me:-) Incredibly, it appears to cause a permanently broken device. The URLs in the commit message have some more details. - Chris. -- Chris Ball One Laptop Per Child