From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 269666B004F for ; Wed, 5 Aug 2009 09:50:53 -0400 (EDT) Date: Wed, 5 Aug 2009 15:50:57 +0200 From: Andi Kleen Subject: Re: [PATCH] [16/19] HWPOISON: Enable .remove_error_page for migration aware file systems Message-ID: <20090805135056.GI11385@basil.fritz.box> References: <200908051136.682859934@firstfloor.org> <20090805093643.E0C00B15D8@basil.firstfloor.org> <20090805111231.GA19532@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090805111231.GA19532@infradead.org> Sender: owner-linux-mm@kvack.org To: Christoph Hellwig Cc: Andi Kleen , tytso@mit.edu, mfasheh@suse.com, aia21@cantab.net, hugh.dickins@tiscali.co.uk, swhiteho@redhat.com, akpm@linux-foundation.org, npiggin@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, fengguang.wu@intel.com, hidehiro.kawai.ez@hitachi.com List-ID: On Wed, Aug 05, 2009 at 07:12:31AM -0400, Christoph Hellwig wrote: > On Wed, Aug 05, 2009 at 11:36:43AM +0200, Andi Kleen wrote: > > > > Enable removing of corrupted pages through truncation > > for a bunch of file systems: ext*, xfs, gfs2, ocfs2, ntfs > > These should cover most server needs. > > > > I chose the set of migration aware file systems for this > > for now, assuming they have been especially audited. > > But in general it should be safe for all file systems > > on the data area that support read/write and truncate. > > > > Caveat: the hardware error handler does not take i_mutex > > for now before calling the truncate function. Is that ok? > > It will probably need locking, e.g. the iolock in XFS. I'll > need to take a look at the actual implementation of > generic_error_remove_page to make sense of this. Thanks for the review. It just calls the lower end of the truncate path. http://git.kernel.org/?p=linux/kernel/git/ak/linux-mce-2.6.git;a=commitdiff;h=b5d3322870b0f6e369809674d2c73857fd6ef480 and http://git.kernel.org/?p=linux/kernel/git/ak/linux-mce-2.6.git;a=commitdiff;h=4c2df4fa9e4687bde815883fabc602ccc5961272 Is that ok? It should be roughly the same as normal truncate does, except it doesn't take i_mutex currently. We're careful to not do it for non regular inodes. > > Is there any way for us to test this functionality without introducing > real hardware problems? Yes, there are three different injectors to chose from :) The easiest one is usually the madvise(MADV_POISON) injector. Just map a suitable page and There's a test program in http://git.kernel.org/?p=utils/cpu/mce/mce-test.git;a=blob;f=tsrc/tinjpage.c;h=954e1edab765d1c141f693ae9767ba9d5491c1aa;hb=HEAD that can be extended for new tests. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org