[PATCH 14/21] Drivers: hv: vss: convert to hv_utils_transport

[K. Y. Srinivasan]

From: Vitaly Kuznetsov <vkuzn...@redhat.com>

Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_vss 
communication methods.

Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
Tested-by: Alex Ng <ale...@microsoft.com>
Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
---
 drivers/hv/hv_snapshot.c |   52 +++++++++++++++++++++++----------------------
 1 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index ddb1cda..2c8c246 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -25,6 +25,7 @@
 #include <linux/hyperv.h>
 
 #include "hyperv_vmbus.h"
+#include "hv_utils_transport.h"
 
 #define VSS_MAJOR  5
 #define VSS_MINOR  0
@@ -58,9 +59,9 @@ static struct {
 
 static void vss_respond_to_host(int error);
 
-static struct cb_id vss_id = { CN_VSS_IDX, CN_VSS_VAL };
-static const char vss_name[] = "vss_kernel_module";
+static const char vss_devname[] = "vmbus/hv_vss";
 static __u8 *recv_buffer;
+static struct hvutil_transport *hvt;
 
 static void vss_send_op(struct work_struct *dummy);
 static void vss_timeout_func(struct work_struct *dummy);
@@ -88,12 +89,12 @@ static void vss_timeout_func(struct work_struct *dummy)
                        hv_vss_onchannelcallback);
 }
 
-static void
-vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
+static int vss_on_msg(void *msg, int len)
 {
-       struct hv_vss_msg *vss_msg;
+       struct hv_vss_msg *vss_msg = (struct hv_vss_msg *)msg;
 
-       vss_msg = (struct hv_vss_msg *)msg->data;
+       if (len != sizeof(*vss_msg))
+               return -EINVAL;
 
        /*
         * Don't process registration messages if we're in the middle of
@@ -101,7 +102,7 @@ vss_cn_callback(struct cn_msg *msg, struct 
netlink_skb_parms *nsp)
         */
        if (vss_transaction.state > HVUTIL_READY &&
            vss_msg->vss_hdr.operation == VSS_OP_REGISTER)
-               return;
+               return -EINVAL;
 
        if (vss_transaction.state == HVUTIL_DEVICE_INIT &&
            vss_msg->vss_hdr.operation == VSS_OP_REGISTER) {
@@ -119,8 +120,9 @@ vss_cn_callback(struct cn_msg *msg, struct 
netlink_skb_parms *nsp)
        } else {
                /* This is a spurious call! */
                pr_warn("VSS: Transaction not active\n");
-               return;
+               return -EINVAL;
        }
+       return 0;
 }
 
 
@@ -128,27 +130,20 @@ static void vss_send_op(struct work_struct *dummy)
 {
        int op = vss_transaction.msg->vss_hdr.operation;
        int rc;
-       struct cn_msg *msg;
        struct hv_vss_msg *vss_msg;
 
        /* The transaction state is wrong. */
        if (vss_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
                return;
 
-       msg = kzalloc(sizeof(*msg) + sizeof(*vss_msg), GFP_ATOMIC);
-       if (!msg)
+       vss_msg = kzalloc(sizeof(*vss_msg), GFP_KERNEL);
+       if (!vss_msg)
                return;
 
-       vss_msg = (struct hv_vss_msg *)msg->data;
-
-       msg->id.idx =  CN_VSS_IDX;
-       msg->id.val = CN_VSS_VAL;
-
        vss_msg->vss_hdr.operation = op;
-       msg->len = sizeof(struct hv_vss_msg);
 
        vss_transaction.state = HVUTIL_USERSPACE_REQ;
-       rc = cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
+       rc = hvutil_transport_send(hvt, vss_msg, sizeof(*vss_msg));
        if (rc) {
                pr_warn("VSS: failed to communicate to the daemon: %d\n", rc);
                if (cancel_delayed_work_sync(&vss_timeout_work)) {
@@ -157,7 +152,7 @@ static void vss_send_op(struct work_struct *dummy)
                }
        }
 
-       kfree(msg);
+       kfree(vss_msg);
 
        return;
 }
@@ -308,14 +303,16 @@ void hv_vss_onchannelcallback(void *context)
 
 }
 
+static void vss_on_reset(void)
+{
+       if (cancel_delayed_work_sync(&vss_timeout_work))
+               vss_respond_to_host(HV_E_FAIL);
+       vss_transaction.state = HVUTIL_DEVICE_INIT;
+}
+
 int
 hv_vss_init(struct hv_util_service *srv)
 {
-       int err;
-
-       err = cn_add_callback(&vss_id, vss_name, vss_cn_callback);
-       if (err)
-               return err;
        recv_buffer = srv->recv_buffer;
 
        /*
@@ -326,13 +323,18 @@ hv_vss_init(struct hv_util_service *srv)
         */
        vss_transaction.state = HVUTIL_DEVICE_INIT;
 
+       hvt = hvutil_transport_init(vss_devname, CN_VSS_IDX, CN_VSS_VAL,
+                                   vss_on_msg, vss_on_reset);
+       if (!hvt)
+               return -EFAULT;
+
        return 0;
 }
 
 void hv_vss_deinit(void)
 {
        vss_transaction.state = HVUTIL_DEVICE_DYING;
-       cn_del_callback(&vss_id);
        cancel_delayed_work_sync(&vss_timeout_work);
        cancel_work_sync(&vss_send_op_work);
+       hvutil_transport_destroy(hvt);
 }
-- 
1.7.4.1

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