Drivers: hv: vmbus: Fix a rescind handling bug
commit ccb61f8a99e6c29df4fb96a65dad4fad740d5be9 upstream.
The host can rescind a channel that has been offered to the
guest and once the channel is rescinded, the host does not
respond to any requests on that channel. Deal with the case where
the guest may be blocked waiting for a response from the host.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f3a8b52..cb95315 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -147,6 +147,29 @@
{ HV_RDV_GUID },
};
+/*
+ * The rescinded channel may be blocked waiting for a response from the host;
+ * take care of that.
+ */
+static void vmbus_rescind_cleanup(struct vmbus_channel *channel)
+{
+ struct vmbus_channel_msginfo *msginfo;
+ unsigned long flags;
+
+
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+
+ list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
+ msglistentry) {
+
+ if (msginfo->waiting_channel == channel) {
+ complete(&msginfo->waitevent);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+}
+
static bool is_unsupported_vmbus_devs(const uuid_le *guid)
{
int i;
@@ -825,6 +848,8 @@
channel->rescind = true;
spin_unlock_irqrestore(&channel->lock, flags);
+ vmbus_rescind_cleanup(channel);
+
if (channel->device_obj) {
if (channel->chn_rescind_callback) {
channel->chn_rescind_callback(channel);