Drivers: hv: vss: Improve log messages.

Adding log messages to help troubleshoot error cases and transaction
handling.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index a6707133c297c7a1435b1bdcda446256671fc080..5c95ba1e2ecf9b0e04381248e667a17f0dde4318 100644 (file)
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -120,7 +120,7 @@ static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
        default:
                return -EINVAL;
        }
-       pr_debug("VSS: userspace daemon ver. %d connected\n", dm_reg_value);
+       pr_info("VSS: userspace daemon ver. %d connected\n", dm_reg_value);
        return 0;
 }
 
@@ -128,8 +128,10 @@ static int vss_on_msg(void *msg, int len)
 {
        struct hv_vss_msg *vss_msg = (struct hv_vss_msg *)msg;
 
-       if (len != sizeof(*vss_msg))
+       if (len != sizeof(*vss_msg)) {
+               pr_debug("VSS: Message size does not match length\n");
                return -EINVAL;
+       }
 
        if (vss_msg->vss_hdr.operation == VSS_OP_REGISTER ||
            vss_msg->vss_hdr.operation == VSS_OP_REGISTER1) {
@@ -137,8 +139,11 @@ static int vss_on_msg(void *msg, int len)
                 * Don't process registration messages if we're in the middle
                 * of a transaction processing.
                 */
-               if (vss_transaction.state > HVUTIL_READY)
+               if (vss_transaction.state > HVUTIL_READY) {
+                       pr_debug("VSS: Got unexpected registration request\n");
                        return -EINVAL;
+               }
+
                return vss_handle_handshake(vss_msg);
        } else if (vss_transaction.state == HVUTIL_USERSPACE_REQ) {
                vss_transaction.state = HVUTIL_USERSPACE_RECV;
@@ -155,7 +160,7 @@ static int vss_on_msg(void *msg, int len)
                }
        } else {
                /* This is a spurious call! */
-               pr_warn("VSS: Transaction not active\n");
+               pr_debug("VSS: Transaction not active\n");
                return -EINVAL;
        }
        return 0;
@@ -168,8 +173,10 @@ static void vss_send_op(void)
        struct hv_vss_msg *vss_msg;
 
        /* The transaction state is wrong. */
-       if (vss_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
+       if (vss_transaction.state != HVUTIL_HOSTMSG_RECEIVED) {
+               pr_debug("VSS: Unexpected attempt to send to daemon\n");
                return;
+       }
 
        vss_msg = kzalloc(sizeof(*vss_msg), GFP_KERNEL);
        if (!vss_msg)
@@ -210,9 +217,13 @@ static void vss_handle_request(struct work_struct *dummy)
        case VSS_OP_HOT_BACKUP:
                if (vss_transaction.state < HVUTIL_READY) {
                        /* Userspace is not registered yet */
+                       pr_debug("VSS: Not ready for request.\n");
                        vss_respond_to_host(HV_E_FAIL);
                        return;
                }
+
+               pr_debug("VSS: Received request for op code: %d\n",
+                       vss_transaction.msg->vss_hdr.operation);
                vss_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
                vss_send_op();
                return;
@@ -353,8 +364,10 @@ hv_vss_init(struct hv_util_service *srv)
 
        hvt = hvutil_transport_init(vss_devname, CN_VSS_IDX, CN_VSS_VAL,
                                    vss_on_msg, vss_on_reset);
-       if (!hvt)
+       if (!hvt) {
+               pr_warn("VSS: Failed to initialize transport\n");
                return -EFAULT;
+       }
 
        return 0;
 }