From: Jesse Gross <jesse@nicira.com>
Date: Wed, 29 Dec 2010 22:48:38 +0000 (-0800)
Subject: datapath: Hold dp->mutex when calling new_vport().
X-Git-Tag: v1.1.0~546
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=f072ebdd57ee86cdc86aac59b5d993cffc37e2e5;p=sliver-openvswitch.git

datapath: Hold dp->mutex when calling new_vport().

On datapath creation we hold dp_mutex but not dp->mutex when
creating the vport for the datapath device.  However, there are
lockdep checks that validate that we hold dp->mutex during the call
to new_vport().  The lock isn't actually necessary in this case
because no one else can access the datapath but it's good to have
the lock assertions, so this holds dp->mutex while initializing
the datapath.

Found with lockdep.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
---

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 67f6730c6..d56bbf702 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -248,6 +248,7 @@ static int create_dp(int dp_idx, const char __user *devnamep)
 		goto err_put_module;
 	INIT_LIST_HEAD(&dp->port_list);
 	mutex_init(&dp->mutex);
+	mutex_lock(&dp->mutex);
 	dp->dp_idx = dp_idx;
 	for (i = 0; i < DP_N_QUEUES; i++)
 		skb_queue_head_init(&dp->queues[i]);
@@ -286,6 +287,7 @@ static int create_dp(int dp_idx, const char __user *devnamep)
 	rcu_assign_pointer(dps[dp_idx], dp);
 	dp_sysfs_add_dp(dp);
 
+	mutex_unlock(&dp->mutex);
 	mutex_unlock(&dp_mutex);
 	rtnl_unlock();
 
@@ -296,6 +298,7 @@ err_destroy_local_port:
 err_destroy_table:
 	tbl_destroy(get_table_protected(dp), NULL);
 err_free_dp:
+	mutex_unlock(&dp->mutex);
 	kfree(dp);
 err_put_module:
 	module_put(THIS_MODULE);
@@ -348,7 +351,7 @@ out:
 	return err;
 }
 
-/* Called with RTNL lock and dp_mutex. */
+/* Called with RTNL lock and dp->mutex. */
 static int new_vport(struct datapath *dp, struct odp_port *odp_port, int port_no)
 {
 	struct vport_parms parms;