diff options
| author | Jason Andryuk <jandryuk@gmail.com> | 2018-02-28 07:23:23 -0500 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2018-02-28 20:20:08 +0100 |
| commit | c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 (patch) | |
| tree | ce54a6673f4658e1323614888b55596e4ec0459a /drivers/net/xen-netfront.c | |
| parent | 910f8befdf5bccf25287d9f1743e3e546bcb7ce0 (diff) | |
xen-netfront: Fix hang on device removal
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>
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 8328d395e332..3127bc8633ca 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -2005,7 +2005,10 @@ 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: @@ -2136,7 +2139,9 @@ 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, |