[PATCH 3.14 06/87] Drivers: hv: util: Fix a bug in the KVP code

Greg Kroah-Hartman
2014-07-26T19:01:40Z

From: "K. Y. Srinivasan" <kys@microsoft.com>

commit 9bd2d0dfe4714dd5d7c09a93a5c9ea9e14ceb3fc upstream.

Add code to poll the channel since we process only one message
at a time and the host may not interrupt us. Also increase the
receive buffer size since some KVP messages are close to 8K bytes in size.

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

---
drivers/hv/hv_kvp.c | 14 ++++++++++++--
drivers/hv/hv_util.c | 2 +-
2 files changed, 13 insertions(+), 3 deletions(-)

--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -127,6 +127,15 @@ kvp_work_func(struct work_struct *dummy)
kvp_respond_to_host(NULL, HV_E_FAIL);
}

+static void poll_channel(struct vmbus_channel *channel)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&channel->inbound_lock, flags);
+ hv_kvp_onchannelcallback(channel);
+ spin_unlock_irqrestore(&channel->inbound_lock, flags);
+}
+
static int kvp_handle_handshake(struct hv_kvp_msg *msg)
{
int ret = 1;
@@ -155,7 +164,7 @@ static int kvp_handle_handshake(struct h
kvp_register(dm_reg_value);
kvp_transaction.active = false;
if (kvp_transaction.kvp_context)
- hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
+ poll_channel(kvp_transaction.kvp_context);
}
return ret;
}
@@ -568,6 +577,7 @@ response_done:

vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
VM_PKT_DATA_INBAND, 0);
+ poll_channel(channel);

}

@@ -603,7 +613,7 @@ void hv_kvp_onchannelcallback(void *cont
return;
}

- vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
+ vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
&requestid);

if (recvlen > 0) {
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -312,7 +312,7 @@ static int util_probe(struct hv_device *
(struct hv_util_service *)dev_id->driver_data;
int ret;

- srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
+ srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
if (!srv->recv_buffer)
return -ENOMEM;
if (srv->util_init) {