[PATCH net] bonding: set correct vlan id for alb xmit path

[Ding Tianhong <dingtianhong@huawei.com>]

The commit d3ab3ffd1d728d7ee77340e7e7e2c7cfe6a4013e
(bonding: use rlb_client_info->vlan_id instead of ->tag)
remove the rlb_client_info->tag, but occur some issues,
The vlan_get_tag() will return 0 for success and -EINVAL for
error, so the client_info->vlan_id always be set to 0 if the
vlan_get_tag return 0 for success, so the client_info would
never get a correct vlan id, and could not send a skb for vlan id 0.

Fix this by convert the client_info->vlan_id from u16 to s16,
and set to -1 for default value, the s16 is enough for the range
of the vlan id.

Fixes: d3ab3ffd1d7 (bonding: use rlb_client_info->vlan_id instead of ->tag)

CC: Ding Tianhong <dingtianhong@huawei.com>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
---
 drivers/net/bonding/bond_alb.c | 8 ++++----
 drivers/net/bonding/bond_alb.h | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index aaeeacf..fa95f70 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -539,7 +539,7 @@ static void rlb_update_client(struct rlb_client_info *client_info)
 
 		skb->dev = client_info->slave->dev;
 
-		if (client_info->vlan_id) {
+		if (client_info->vlan_id >= 0) {
 			skb = vlan_put_tag(skb, htons(ETH_P_8021Q), client_info->vlan_id);
 			if (!skb) {
 				pr_err("%s: Error: failed to insert VLAN tag\n",
@@ -722,8 +722,8 @@ static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bon
 			client_info->ntt = 0;
 		}
 
-		if (!vlan_get_tag(skb, &client_info->vlan_id))
-			client_info->vlan_id = 0;
+		if (vlan_get_tag(skb, &client_info->vlan_id))
+			client_info->vlan_id = -1;
 
 		if (!client_info->assigned) {
 			u32 prev_tbl_head = bond_info->rx_hashtbl_used_head;
@@ -827,7 +827,7 @@ static void rlb_init_table_entry_dst(struct rlb_client_info *entry)
 	entry->used_prev = RLB_NULL_INDEX;
 	entry->assigned = 0;
 	entry->slave = NULL;
-	entry->vlan_id = 0;
+	entry->vlan_id = -1;
 }
 static void rlb_init_table_entry_src(struct rlb_client_info *entry)
 {
diff --git a/drivers/net/bonding/bond_alb.h b/drivers/net/bonding/bond_alb.h
index e09dd4bf..b49af98 100644
--- a/drivers/net/bonding/bond_alb.h
+++ b/drivers/net/bonding/bond_alb.h
@@ -125,7 +125,7 @@ struct rlb_client_info {
 	u8  assigned;		/* checking whether this entry is assigned */
 	u8  ntt;		/* flag - need to transmit client info */
 	struct slave *slave;	/* the slave assigned to this client */
-	unsigned short vlan_id;	/* VLAN tag associated with IP address */
+	short vlan_id;		/* VLAN tag associated with IP address */
 };
 
 struct tlb_slave_info {
-- 
1.8.0