From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754865Ab0I1WA4 (ORCPT ); Tue, 28 Sep 2010 18:00:56 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:50667 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752855Ab0I1WAz (ORCPT ); Tue, 28 Sep 2010 18:00:55 -0400 Date: Tue, 28 Sep 2010 15:00:00 -0700 From: Andrew Morton To: Richard Weinberger Cc: linux-kernel@vger.kernel.org, jdike@addtoit.com, user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, janjaap@bos.nl, geert@linux-m68k.org, jaxboe@fusionio.com, martin.petersen@oracle.com, adobriyan@gmail.com, cdfrey@foursquare.net Subject: Re: [PATCH 1/1] um: ubd: Fix data corruption Message-Id: <20100928150000.f007f43e.akpm@linux-foundation.org> In-Reply-To: <1285710456-4435-1-git-send-email-richard@nod.at> References: <1285710456-4435-1-git-send-email-richard@nod.at> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Sep 2010 23:47:36 +0200 Richard Weinberger wrote: > Under high load the file system gets corrupted. > This patch fixes the issue. > > Many thanks to Janjaap Bos ! > > LKML-Reference: > Signed-off-by: Richard Weinberger > --- > arch/um/drivers/ubd_kern.c | 7 +++++-- > 1 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c > index 1bcd208..2874b83 100644 > --- a/arch/um/drivers/ubd_kern.c > +++ b/arch/um/drivers/ubd_kern.c > @@ -748,9 +748,12 @@ static int ubd_open_dev(struct ubd *ubd_dev) > } > ubd_dev->fd = fd; > > - if(ubd_dev->cow.file != NULL){ > - blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long)); > + /* A setting higher than 1 sector currently (>= v2.6.31) generates > + data loss, both for raw and cow ubd. */ > + blk_queue_max_hw_sectors(ubd_dev->queue, 1 * sizeof(long)); > + blk_queue_max_segments(ubd_dev->queue, 1 * sizeof(long)); > > + if (ubd_dev->cow.file != NULL) { > err = -ENOMEM; > ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len); > if(ubd_dev->cow.bitmap == NULL){ This is a workaround, I think? Do we know what the actual bug is? >>From the comment it appears to be a regression?