ovs_vport_cmd_dump() did rcu_read_lock() only after getting the
datapath, which could have been deleted in between. Resolved by
taking rcu_read_lock() before the get_dp() call.
Remove unnecessary locking from functions that are always called with
appropriate locking (get_dp(), ovs_dp_cmd_fill_info(),
lookup_datapath()).
Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
---
datapath/datapath.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 5f1b34c..7992330 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -116,20 +116,19 @@ static int queue_gso_packets(struct datapath *dp, struct
sk_buff *,
static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,
const struct dp_upcall_info *);
-/* Must be called with rcu_read_lock or ovs_mutex. */
+/* Must be called with rcu_read_lock or ovs_mutex, so no additional protection
+ * is needed here. */
static struct datapath *get_dp(struct net *net, int dp_ifindex)
{
struct datapath *dp = NULL;
struct net_device *dev;
- rcu_read_lock();
dev = dev_get_by_index_rcu(net, dp_ifindex);
if (dev) {
struct vport *vport = ovs_internal_dev_get_vport(dev);
if (vport)
dp = vport->dp;
}
- rcu_read_unlock();
return dp;
}
@@ -175,6 +174,7 @@ static struct hlist_head *vport_hash_bucket(const struct
datapath *dp,
return &dp->ports[port_no & (DP_VPORT_HASH_BUCKETS - 1)];
}
+/* Called with ovs_mutex or RCU read lock. */
struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no)
{
struct vport *vport;
@@ -650,7 +650,7 @@ static size_t ovs_flow_cmd_msg_size(const struct
sw_flow_actions *acts)
+ nla_total_size(acts->actions_len); /* OVS_FLOW_ATTR_ACTIONS */
}
-/* Called with ovs_mutex. */
+/* Must be called with rcu_read_lock or ovs_mutex. */
static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
struct sk_buff *skb, u32 portid,
u32 seq, u32 flags, u8 cmd)
@@ -741,6 +741,7 @@ error:
return err;
}
+/* Must be called with rcu_read_lock or ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
struct genl_info *info)
{
@@ -751,6 +752,7 @@ static struct sk_buff *ovs_flow_cmd_alloc_info(struct
sw_flow *flow,
return genlmsg_new_unicast(len, info, GFP_KERNEL);
}
+/* Must be called with rcu_read_lock or ovs_mutex. */
static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
struct datapath *dp,
struct genl_info *info,
@@ -1091,6 +1093,7 @@ static size_t ovs_dp_cmd_msg_size(void)
return msgsize;
}
+/* Must be called with rcu_read_lock or ovs_mutex. */
static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
u32 portid, u32 seq, u32 flags, u8 cmd)
{
@@ -1106,9 +1109,7 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp,
struct sk_buff *skb,
ovs_header->dp_ifindex = get_dpifindex(dp);
- rcu_read_lock();
err = nla_put_string(skb, OVS_DP_ATTR_NAME, ovs_dp_name(dp));
- rcu_read_unlock();
if (err)
goto nla_put_failure;
@@ -1133,6 +1134,7 @@ error:
return -EMSGSIZE;
}
+/* Must be called with rcu_read_lock or ovs_mutex. */
static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp,
struct genl_info *info, u8 cmd)
{
@@ -1151,7 +1153,7 @@ static struct sk_buff *ovs_dp_cmd_build_info(struct
datapath *dp,
return skb;
}
-/* Called with ovs_mutex. */
+/* Called with rcu_read_lock or ovs_mutex. */
static struct datapath *lookup_datapath(struct net *net,
struct ovs_header *ovs_header,
struct nlattr *a[OVS_DP_ATTR_MAX + 1])
@@ -1163,10 +1165,8 @@ static struct datapath *lookup_datapath(struct net *net,
else {
struct vport *vport;
- rcu_read_lock();
vport = ovs_vport_locate(net, nla_data(a[OVS_DP_ATTR_NAME]));
dp = vport && vport->port_no == OVSP_LOCAL ? vport->dp : NULL;
- rcu_read_unlock();
}
return dp ? dp : ERR_PTR(-ENODEV);
}
@@ -1764,11 +1764,12 @@ static int ovs_vport_cmd_dump(struct sk_buff *skb,
struct netlink_callback *cb)
int bucket = cb->args[0], skip = cb->args[1];
int i, j = 0;
+ rcu_read_lock();
dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
- if (!dp)
+ if (!dp) {
+ rcu_read_unlock();
return -ENODEV;
-
- rcu_read_lock();
+ }
for (i = bucket; i < DP_VPORT_HASH_BUCKETS; i++) {
struct vport *vport;
--
1.7.10.4
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