From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Lavinen Subject: Re: BUG_ON in recovery.c after powercut Date: Wed, 16 Oct 2013 19:20:44 +0300 Message-ID: <20131016162043.GA10000@wsf-1107.seri.co.uk> References: <1381812859.992.26.camel@kjgkr> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VWTqE-0007yH-Bv for linux-f2fs-devel@lists.sourceforge.net; Wed, 16 Oct 2013 16:20:58 +0000 Received: from mailout3.w1.samsung.com ([210.118.77.13]) by sog-mx-4.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1VWTqC-0008Cy-4d for linux-f2fs-devel@lists.sourceforge.net; Wed, 16 Oct 2013 16:20:58 +0000 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MUR00DDRS2DS4B0@mailout3.w1.samsung.com> for linux-f2fs-devel@lists.sourceforge.net; Wed, 16 Oct 2013 17:20:49 +0100 (BST) Content-disposition: inline In-reply-to: <1381812859.992.26.camel@kjgkr> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Jan Altenberg Cc: linux-f2fs-devel@lists.sourceforge.net > If possible, can you test the below scenario with the latest f2fs? I would be also interested in studying such image, so could you please send it to me also? I am concerned or curious about F2FS tolerance against power cuts. In my previous life at Nokia we did once power cut testing for ext3 and ext4 file systems on eMMC. There was an AC switch which cut the power off at random times. Ext3 didn't survive the test, ext4 did. Test script was doing various operations in a logged manner so that data integrity could be verified and one could also see what operations had been done just before the power went off. Wit AC switch the voltage drops linearly and doesn't exactly match the case of losing battery abruptly. DC power switching or hard reseting the eMMC would be closer. Perhaps using USB switch with external USB reader one could cut the power sharply from the reader and again simulate sharp power loss scenario giving no mercy for the FTL. Cheers Jarkko Lavinen ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk