From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Richard Weinberger Subject: [PATCH 1/1] um: ubd: Fix data corruption Date: Tue, 28 Sep 2010 23:47:36 +0200 Message-Id: <1285710456-4435-1-git-send-email-richard@nod.at> To: akpm@linux-foundation.org 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, Richard Weinberger List-ID: 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){ -- 1.6.6.1