[d/azure][PATCH 1/2] UBUNTU: SAUCE: Don't wait in hvnd_query_gid after interface is already bound to ND

[Marcelo Henrique Cerri]

From: Long Li <longli at microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/1839673

The user mode may call hvnd_query_gid multiple times, and from multiple user
contexts at the same time. If it's already bound, return GID and not wait.

Signed-off-by: Long Li <longli at microsoft.com>
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 .../hw/vmbus-rdma/vmbus-rdma-144.0/provider.c          | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/hw/vmbus-rdma/vmbus-rdma-144.0/provider.c b/drivers/infiniband/hw/vmbus-rdma/vmbus-rdma-144.0/provider.c
index 8e15522707b9..3ad27e9d6a5d 100644
--- a/drivers/infiniband/hw/vmbus-rdma/vmbus-rdma-144.0/provider.c
+++ b/drivers/infiniband/hw/vmbus-rdma/vmbus-rdma-144.0/provider.c
@@ -604,9 +604,11 @@ static int hvnd_query_gid(struct ib_device *ibdev, u8 port, int index,
 
 	debug_check(__func__, __LINE__);
 
-	ret = wait_for_completion_timeout(&nd_dev->addr_set, 60*HZ);
-	if (!ret)
-		return -ETIMEDOUT;
+	if (!nd_dev->bind_complete) {
+		ret = wait_for_completion_timeout(&nd_dev->addr_set, 60*HZ);
+		if (!ret && !nd_dev->bind_complete)
+			return -ETIMEDOUT;
+	}
 
 	memset(&(gid->raw[0]), 0, sizeof(gid->raw));
 	memcpy(&(gid->raw[0]), nd_dev->mac_addr, 6);
@@ -2752,8 +2754,8 @@ static int hvnd_try_bind_nic(unsigned char *mac, __be32 ip)
 	/* if we reach here, this means bind_nic is a success */
 	hvnd_error("successfully bound to IP %pI4 MAC %pM\n",
 		   nd_dev->ip_addr, nd_dev->mac_addr);
-	complete(&nd_dev->addr_set);
 	nd_dev->bind_complete = 1;
+	complete_all(&nd_dev->addr_set);
 	mutex_unlock(&nd_dev->bind_mutex);
 
 	ret = hvnd_register_device(nd_dev, nd_dev->ip_addr, nd_dev->mac_addr);
-- 
2.20.1