[PATCH] xen-blkback: only set Closed state when resources have been released

[Roger Pau Monne]

Don't set the backend to Closed state until all the resources have
been released and the blkback instance is gone. Setting the backend
state to Closed will be done by xenbus_dev_remove after removing the
device instance.

Note that this requires disconnecting and allowing reconnection with
state Closing, since the Closed state will only be reached when
detaching the device.

Reported-by: Valentin Vidic <Valentin.Vidic at carnet.hr>
Signed-off-by: Roger Pau Monné <roger.pau at citrix.com>
---
 drivers/block/xen-blkback/xenbus.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index a4bc74e72c39..b0629f1b0511 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -770,7 +770,8 @@ static void frontend_changed(struct xenbus_device *dev,
 
 	switch (frontend_state) {
 	case XenbusStateInitialising:
-		if (dev->state == XenbusStateClosed) {
+		if (dev->state == XenbusStateClosed ||
+		    dev->state == XenbusStateClosing) {
 			pr_info("%s: prepare for reconnect\n", dev->nodename);
 			xenbus_switch_state(dev, XenbusStateInitWait);
 		}
@@ -809,12 +810,12 @@ static void frontend_changed(struct xenbus_device *dev,
 		break;
 
 	case XenbusStateClosing:
+		xen_blkif_disconnect(be->blkif);
 		xenbus_switch_state(dev, XenbusStateClosing);
 		break;
 
 	case XenbusStateClosed:
 		xen_blkif_disconnect(be->blkif);
-		xenbus_switch_state(dev, XenbusStateClosed);
 		if (xenbus_dev_is_online(dev))
 			break;
 		/* fall through */
-- 
2.18.0