From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 8C5FB6B004F for ; Wed, 3 Jun 2009 11:02:30 -0400 (EDT) Date: Wed, 3 Jun 2009 11:35:46 +0200 From: Nick Piggin Subject: Re: [PATCH] [13/16] HWPOISON: The high level memory error handler in the VM v3 Message-ID: <20090603093546.GA16275@wotan.suse.de> References: <20090528122357.GM6920@wotan.suse.de> <20090528135428.GB16528@localhost> <20090601115046.GE5018@wotan.suse.de> <20090601183225.GS1065@one.firstfloor.org> <20090602120042.GB1392@wotan.suse.de> <20090602124757.GG1065@one.firstfloor.org> <20090602125713.GG1392@wotan.suse.de> <20090602134659.GA21338@localhost> <20090602151729.GC17448@wotan.suse.de> <20090602172715.GT1065@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090602172715.GT1065@one.firstfloor.org> Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: Wu Fengguang , "hugh@veritas.com" , "riel@redhat.com" , "akpm@linux-foundation.org" , "chris.mason@oracle.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" List-ID: On Tue, Jun 02, 2009 at 07:27:15PM +0200, Andi Kleen wrote: > > Hmm, if you're handling buffercache here then possibly yes. > > Good question, will check. BTW. now that I think about it, buffercache is probably not a good idea to truncate (truncate, as-in: remove from pagecache). Because filesystems can assume that with just a reference on the page, then it will not be truncated. This code will cause ext2 (as the first one I looked at), to go oops. And this is not predicated on PagePrivate or page_has_buffers, because filesystems are free to directly operate on their own metadata buffercache pages. So I think it would be a good idea to exclude buffercache from here completely until it can be shown to be safe. Actually you *can* use the invalidate_mapping_pages path, which will check refcounts etc (or a derivative thereof, similarly to my truncate patch). -- 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