From f12bf6f3f942b37de65eeea8be25903587fec930 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 6 Dec 2021 17:30:30 -0800 Subject: [PATCH] net: watchdog: add net device refcount tracker Add a netdevice_tracker inside struct net_device, to track the self reference when a device has an active watchdog timer. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 2 ++ net/sched/sch_generic.c | 10 ++++++---- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 69dca1edd5a6..1a748ee9a421 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1951,6 +1951,7 @@ enum netdev_ml_priv_type { * * @dev_addr_shadow: Copy of @dev_addr to catch direct writes. * @linkwatch_dev_tracker: refcount tracker used by linkwatch. + * @watchdog_dev_tracker: refcount tracker used by watchdog. * * FIXME: cleanup struct net_device such that network protocol info * moves out. @@ -2282,6 +2283,7 @@ struct net_device { u8 dev_addr_shadow[MAX_ADDR_LEN]; netdevice_tracker linkwatch_dev_tracker; + netdevice_tracker watchdog_dev_tracker; }; #define to_net_dev(d) container_of(d, struct net_device, dev) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 8c8fbf2e3856..b07bd1c7330f 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -499,6 +499,7 @@ EXPORT_SYMBOL(netif_tx_unlock); static void dev_watchdog(struct timer_list *t) { struct net_device *dev = from_timer(dev, t, watchdog_timer); + bool release = true; spin_lock(&dev->tx_global_lock); if (!qdisc_tx_is_noop(dev)) { @@ -534,12 +535,13 @@ static void dev_watchdog(struct timer_list *t) if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) - dev_hold(dev); + release = false; } } spin_unlock(&dev->tx_global_lock); - dev_put(dev); + if (release) + dev_put_track(dev, &dev->watchdog_dev_tracker); } void __netdev_watchdog_up(struct net_device *dev) @@ -549,7 +551,7 @@ void __netdev_watchdog_up(struct net_device *dev) dev->watchdog_timeo = 5*HZ; if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) - dev_hold(dev); + dev_hold_track(dev, &dev->watchdog_dev_tracker, GFP_ATOMIC); } } EXPORT_SYMBOL_GPL(__netdev_watchdog_up); @@ -563,7 +565,7 @@ static void dev_watchdog_down(struct net_device *dev) { netif_tx_lock_bh(dev); if (del_timer(&dev->watchdog_timer)) - dev_put(dev); + dev_put_track(dev, &dev->watchdog_dev_tracker); netif_tx_unlock_bh(dev); } -- GitLab