diff options
| author | Jason Andryuk <jandryuk@gmail.com> | 2018-02-28 07:23:23 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-24 09:32:06 +0200 |
| commit | 4c65e94eb476b8e7d806d7e36ca1f5f789e9804a (patch) | |
| tree | c5c7756efb02d7e8fb227e6639899185812dcd13 /drivers/net/xen-netfront.c | |
| parent | 318a306c53d17fa333d888d29c45268c6a8b1783 (diff) | |
xen-netfront: Fix hang on device removal
commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 upstream.
A toolstack may delete the vif frontend and backend xenstore entries
while xen-netfront is in the removal code path. In that case, the
checks for xenbus_read_driver_state would return XenbusStateUnknown, and
xennet_remove would hang indefinitely. This hang prevents system
shutdown.
xennet_remove must be able to handle XenbusStateUnknown, and
netback_changed must also wake up the wake_queue for that state as well.
Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading module")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Cc: Eduardo Otubo <otubo@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/xen-netfront.c')
| -rw-r--r-- | drivers/net/xen-netfront.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 0b8d2655985f..fee4c01fbdfd 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -2024,7 +2024,10 @@ static void netback_changed(struct xenbus_device *dev, case XenbusStateInitialised: case XenbusStateReconfiguring: case XenbusStateReconfigured: + break; + case XenbusStateUnknown: + wake_up_all(&module_unload_q); break; case XenbusStateInitWait: @@ -2155,7 +2158,9 @@ static int xennet_remove(struct xenbus_device *dev) xenbus_switch_state(dev, XenbusStateClosing); wait_event(module_unload_q, xenbus_read_driver_state(dev->otherend) == - XenbusStateClosing); + XenbusStateClosing || + xenbus_read_driver_state(dev->otherend) == + XenbusStateUnknown); xenbus_switch_state(dev, XenbusStateClosed); wait_event(module_unload_q, |