From 28afea5b2ffaa48f4f43d22ae8edcc384c05df80 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 19 May 2009 08:25:48 +0200 Subject: [PATCH] xen/blkfront: allow xenbus state transition to Closing->Closed when not Connected This situation can occur when attempting to attach a block device whose backend is an empty physical CD-ROM driver. The backend in this case will go directly from the Initialising state to Closing->Closed. Previously this would result in a NULL pointer deref on info->gd (xenbus_dev_fatal does not return as a1a15ac5 seems to expect) Cc: stable@kernel.org Signed-off-by: Ian Campbell Acked-by: Jeremy Fitzhardinge Signed-off-by: Jens Axboe --- drivers/block/xen-blkfront.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 8f905089b72..6971a12e8b9 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -977,8 +977,10 @@ static void backend_changed(struct xenbus_device *dev, break; case XenbusStateClosing: - if (info->gd == NULL) - xenbus_dev_fatal(dev, -ENODEV, "gd is NULL"); + if (info->gd == NULL) { + xenbus_frontend_closed(dev); + break; + } bd = bdget_disk(info->gd, 0); if (bd == NULL) xenbus_dev_fatal(dev, -ENODEV, "bdget failed"); -- 2.20.1