From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756537Ab1GMAuE (ORCPT ); Tue, 12 Jul 2011 20:50:04 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:58686 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753938Ab1GMAuD (ORCPT ); Tue, 12 Jul 2011 20:50:03 -0400 X-Greylist: delayed 147370 seconds by postgrey-1.27 at vger.kernel.org; Tue, 12 Jul 2011 20:50:03 EDT Message-ID: <4E1CEB34.5090907@oracle.com> Date: Wed, 13 Jul 2011 08:47:48 +0800 From: Joe Jin User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Lightning/1.0b3pre OracleBeehiveExtension/1.0.0.2-OracleInternal ObetStats/CATLAF_1292475699435-498544290 Thunderbird/3.1.10 MIME-Version: 1.0 To: Daniel Stodden , Jens Axboe , annie.li@oracle.com, Jeremy Fitzhardinge , Ian Campbell , Konrad Rzeszutek Wilk , Kurt C Hackel , Greg Marsden CC: "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , stable@kernel.org Subject: [PATCH resubmit] xen-blkfront: Don't send closing notification to backend in blkfront_closing() Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: rtcsinet22.oracle.com [66.248.204.30] X-CT-RefId: str=0001.0A090202.4E1CEB4D.004C:SCFSTAT5015188,ss=1,re=-4.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we do block device attach/detach test with below steps, umount hang and the guest unable to shutdown: 1. start guest with the latest kernel. 2. attach new block device by xm block-attach in Dom0 3. mount new disk in guest 4. execute xm block-detach to detach the block device in dom0 until timeout 5. try to unmount the disk in guest, umount hung. at here, any IOs to the device will hang. Checking the code found when 'xm block-detach' set backend device's state to 'XenbusStateClosing', frontend received the notification and blkfront_closing() be called, at the moment, the disk still using by guest, so frontend refused to close. In the blkfront_closing(), frontend send a notification to backend said that the its state switched to 'Closing', when backend got the event, it will disconnect from real device, at here any IO request will be stuck, even tried to release the disk by umount. Per our test, below patch fix this issue. Signed-off-by: Joe Jin Signed-off-by: Annie Li Reviewed-by: Konrad Rzeszutek Wilk Cc: Jens Axboe Cc: stable@kernel.org --- xen-blkfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index b536a9c..f6d8ac2 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1088,7 +1088,7 @@ blkfront_closing(struct blkfront_info *info) if (bdev->bd_openers) { xenbus_dev_error(xbdev, -EBUSY, "Device in use; refusing to close"); - xenbus_switch_state(xbdev, XenbusStateClosing); + xbdev->state = XenbusStateClosing; } else { xlvbd_release_gendisk(info); xenbus_frontend_closed(xbdev);