From 08294a26e15d7baf1e14ee569e9f2bc82a7ae768 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 30 Jun 2016 14:45:35 +0800 Subject: [PATCH] net: introduce NETDEV_CHANGE_TX_QUEUE_LEN This patch introduces a new event - NETDEV_CHANGE_TX_QUEUE_LEN, this will be triggered when tx_queue_len. It could be used by net device who want to do some processing at that time. An example is tun who may want to resize tx array when tx_queue_len is changed. Cc: John Fastabend Signed-off-by: Jason Wang Acked-by: John Fastabend Signed-off-by: David S. Miller --- include/linux/netdevice.h | 1 + net/core/net-sysfs.c | 15 ++++++++++++++- net/core/rtnetlink.c | 16 ++++++++++++---- 3 files changed, 27 insertions(+), 5 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e84d9d23c2d5..7dc2ec74122a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2237,6 +2237,7 @@ struct netdev_lag_lower_state_info { #define NETDEV_PRECHANGEUPPER 0x001A #define NETDEV_CHANGELOWERSTATE 0x001B #define NETDEV_UDP_TUNNEL_PUSH_INFO 0x001C +#define NETDEV_CHANGE_TX_QUEUE_LEN 0x001E int register_netdevice_notifier(struct notifier_block *nb); int unregister_netdevice_notifier(struct notifier_block *nb); diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 7a0b616557ab..6e4f34721080 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -322,7 +322,20 @@ NETDEVICE_SHOW_RW(flags, fmt_hex); static int change_tx_queue_len(struct net_device *dev, unsigned long new_len) { - dev->tx_queue_len = new_len; + int res, orig_len = dev->tx_queue_len; + + if (new_len != orig_len) { + dev->tx_queue_len = new_len; + res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev); + res = notifier_to_errno(res); + if (res) { + netdev_err(dev, + "refused to change device tx_queue_len\n"); + dev->tx_queue_len = orig_len; + return -EFAULT; + } + } + return 0; } diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index cfed7bc14ee6..a9e3805af739 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1927,11 +1927,19 @@ static int do_setlink(const struct sk_buff *skb, if (tb[IFLA_TXQLEN]) { unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]); - - if (dev->tx_queue_len ^ value) + unsigned long orig_len = dev->tx_queue_len; + + if (dev->tx_queue_len ^ value) { + dev->tx_queue_len = value; + err = call_netdevice_notifiers( + NETDEV_CHANGE_TX_QUEUE_LEN, dev); + err = notifier_to_errno(err); + if (err) { + dev->tx_queue_len = orig_len; + goto errout; + } status |= DO_SETLINK_NOTIFY; - - dev->tx_queue_len = value; + } } if (tb[IFLA_OPERSTATE]) -- 2.39.5