Drivers: hv: util: kvp: Fix a rescind processing issue

KVP may use a char device to support the communication between
the user level daemon and the driver. When the KVP channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new KVP offer from the host. Implement this logic.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 5e1fdc8d32ab0c03d25bfcf7d3fbadbcedc6f2eb..3abfc5983c97c87f6457111a937d4f330ba185e1 100644 (file)
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -88,6 +88,7 @@ static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
 static const char kvp_devname[] = "vmbus/hv_kvp";
 static u8 *recv_buffer;
 static struct hvutil_transport *hvt;
+static struct completion release_event;
 /*
  * Register the kernel component with the user-level daemon.
  * As part of this registration, pass the LIC version number.
@@ -716,6 +717,7 @@ static void kvp_on_reset(void)
        if (cancel_delayed_work_sync(&kvp_timeout_work))
                kvp_respond_to_host(NULL, HV_E_FAIL);
        kvp_transaction.state = HVUTIL_DEVICE_INIT;
+       complete(&release_event);
 }
 
 int
@@ -724,6 +726,7 @@ hv_kvp_init(struct hv_util_service *srv)
        recv_buffer = srv->recv_buffer;
        kvp_transaction.recv_channel = srv->channel;
 
+       init_completion(&release_event);
        /*
         * When this driver loads, the user level daemon that
         * processes the host requests may not yet be running.
@@ -747,4 +750,5 @@ void hv_kvp_deinit(void)
        cancel_delayed_work_sync(&kvp_timeout_work);
        cancel_work_sync(&kvp_sendkey_work);
        hvutil_transport_destroy(hvt);
+       wait_for_completion(&release_event);
 }