Drivers: hv: vss: process deferred messages when we complete the transaction
authorVitaly Kuznetsov <vkuznets@redhat.com>
Sun, 12 Apr 2015 01:07:43 +0000 (18:07 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 19:17:40 +0000 (12:17 -0700)
In theory, the host is not supposed to issue any requests before be reply to
the previous one. In KVP we, however, support the following scenarios:
1) A message was received before userspace daemon registered;
2) A message was received while the previous one is still being processed.
In VSS we support only the former. Add support for the later, use
hv_poll_channel() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hv/hv_snapshot.c

index c1a3604..4bb9b1c 100644 (file)
@@ -47,6 +47,7 @@ static struct {
        struct vmbus_channel *recv_channel; /* chn we got the request */
        u64 recv_req_id; /* request ID. */
        struct hv_vss_msg  *msg; /* current message */
+       void *vss_context; /* for the channel callback */
 } vss_transaction;
 
 
@@ -73,6 +74,9 @@ static void vss_timeout_func(struct work_struct *dummy)
         */
        pr_warn("VSS: timeout waiting for daemon to reply\n");
        vss_respond_to_host(HV_E_FAIL);
+
+       hv_poll_channel(vss_transaction.vss_context,
+                       hv_vss_onchannelcallback);
 }
 
 static void
@@ -85,13 +89,12 @@ vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
        if (vss_msg->vss_hdr.operation == VSS_OP_REGISTER) {
                pr_info("VSS daemon registered\n");
                vss_transaction.active = false;
-               if (vss_transaction.recv_channel != NULL)
-                       hv_vss_onchannelcallback(vss_transaction.recv_channel);
-               return;
-
        }
        if (cancel_delayed_work_sync(&vss_timeout_work))
                vss_respond_to_host(vss_msg->error);
+
+       hv_poll_channel(vss_transaction.vss_context,
+                       hv_vss_onchannelcallback);
 }
 
 
@@ -198,9 +201,10 @@ void hv_vss_onchannelcallback(void *context)
                 * We will defer processing this callback once
                 * the current transaction is complete.
                 */
-               vss_transaction.recv_channel = channel;
+               vss_transaction.vss_context = context;
                return;
        }
+       vss_transaction.vss_context = NULL;
 
        vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
                         &requestid);