rtnl/do_setlink(): set modified when IFLA_TXQLEN is updated

The only effect of this patch is to print a warning if IFLA_TXQLEN is updated
and a following change fails.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f0493e3b7471..5bbaf74bf457 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1611,8 +1611,14 @@ static int do_setlink(const struct sk_buff *skb,
                 modified = 1;
         }
 
-        if (tb[IFLA_TXQLEN])
-                dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
+        if (tb[IFLA_TXQLEN]) {
+                unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]);
+
+                if (dev->tx_queue_len ^ value)
+                        modified = 1;
+
+                dev->tx_queue_len = value;
+        }
 
         if (tb[IFLA_OPERSTATE])
                 set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));