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net: add retry mechanism to ndo_set_rx_mode_async

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When ndo_set_rx_mode_async returns an error, schedule a retry with
exponential backoff (1s, 2s, 4s, 8s -- 15s total). Give up after the
4th retry and log an error via netdev_err().

This moves retry logic from individual drivers into the core stack.

Timer callback does not hold a ref on dev. Safe because the timer can
only be armed when dev is IFF_UP, and __dev_close_many runs
timer_delete_sync before clearing IFF_UP. Unregister always closes
IFF_UP devices first, so by the time dev can be freed the timer is
dead and cannot be re-armed.

Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260608154014.227538-3-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Stanislav Fomichev
2026-06-08 08:40:13 -07:00
committed by Jakub Kicinski
parent d11706b56a
commit d90b85c23b
4 changed files with 60 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
include/linux/netdevice.h
View File

@@ -1933,6 +1933,8 @@ enum netdev_reg_state {
* @rx_mode_node: List entry for rx_mode work processing
* @rx_mode_tracker: Refcount tracker for rx_mode work
* @rx_mode_addr_cache: Recycled snapshot entries for rx_mode work
* @rx_mode_retry_timer: Timer that re-queues rx_mode work after failure
* @rx_mode_retry_count: Number of consecutive retries already scheduled
* @uc: unicast mac addresses
* @mc: multicast mac addresses
* @dev_addrs: list of device hw addresses
@@ -2326,6 +2328,8 @@ struct net_device {
struct list_head rx_mode_node;
netdevice_tracker rx_mode_tracker;
struct netdev_hw_addr_list rx_mode_addr_cache;
struct timer_list rx_mode_retry_timer;
unsigned int rx_mode_retry_count;
#ifdef CONFIG_LOCKDEP
unsigned char nested_level;
#endif
@@ -5152,6 +5156,7 @@ static inline void __dev_mc_unsync(struct net_device *dev,
/* Functions used for secondary unicast and multicast support */
void dev_set_rx_mode(struct net_device *dev);
void netif_rx_mode_schedule_retry(struct net_device *dev);
int netif_set_promiscuity(struct net_device *dev, int inc);
int dev_set_promiscuity(struct net_device *dev, int inc);
int netif_set_allmulti(struct net_device *dev, int inc, bool notify);

4
net/core/dev.c
View File

@@ -1775,6 +1775,7 @@ static void __dev_close_many(struct list_head *head)
if (ops->ndo_stop)
ops->ndo_stop(dev);
netif_rx_mode_cancel_retry(dev);
netif_set_up(dev, false);
netpoll_poll_enable(dev);
}
@@ -12094,8 +12095,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
#endif
mutex_init(&dev->lock);
INIT_LIST_HEAD(&dev->rx_mode_node);
__hw_addr_init(&dev->rx_mode_addr_cache);
netif_rx_mode_init(dev);
dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
setup(dev);

2
net/core/dev.h
View File

@@ -166,8 +166,10 @@ int dev_change_carrier(struct net_device *dev, bool new_carrier);
void __dev_set_rx_mode(struct net_device *dev);
int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify);
void netif_rx_mode_init(struct net_device *dev);
bool netif_rx_mode_clean(struct net_device *dev);
void netif_rx_mode_sync(struct net_device *dev);
void netif_rx_mode_cancel_retry(struct net_device *dev);
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
unsigned int gchanges, u32 portid,

53
net/core/dev_addr_lists.c
View File

@@ -1252,6 +1252,35 @@ static int netif_uc_promisc_update(struct net_device *dev)
return 0;
}
/* Total retry budget (4): 1+2+4+8 = 15 seconds */
#define NETIF_RX_MODE_RETRY_MAX 4
void netif_rx_mode_schedule_retry(struct net_device *dev)
{
unsigned long delay;
netdev_assert_locked_ops_compat(dev);
if (dev->rx_mode_retry_count >= NETIF_RX_MODE_RETRY_MAX) {
netdev_err(dev, "rx_mode retry limit reached, giving up\n");
return;
}
delay = HZ << dev->rx_mode_retry_count;
if (mod_timer(&dev->rx_mode_retry_timer, jiffies + delay))
return;
if (!dev->rx_mode_retry_count)
netdev_info(dev, "rx_mode install failed, retrying with backoff\n");
dev->rx_mode_retry_count++;
}
EXPORT_SYMBOL_GPL(netif_rx_mode_schedule_retry);
void netif_rx_mode_cancel_retry(struct net_device *dev)
{
timer_delete_sync(&dev->rx_mode_retry_timer);
dev->rx_mode_retry_count = 0;
}
static void netif_rx_mode_run(struct net_device *dev)
{
struct netdev_hw_addr_list uc_snap, mc_snap, uc_ref, mc_ref;
@@ -1275,8 +1304,8 @@ static void netif_rx_mode_run(struct net_device *dev)
err = netif_addr_lists_snapshot(dev, &uc_snap, &mc_snap,
&uc_ref, &mc_ref);
if (err) {
netdev_WARN(dev, "failed to sync uc/mc addresses\n");
netif_addr_unlock_bh(dev);
netif_rx_mode_schedule_retry(dev);
return;
}
@@ -1292,12 +1321,17 @@ static void netif_rx_mode_run(struct net_device *dev)
__dev_set_promiscuity(dev, promisc_inc, false);
if (ops->ndo_set_rx_mode_async) {
ops->ndo_set_rx_mode_async(dev, &uc_snap, &mc_snap);
err = ops->ndo_set_rx_mode_async(dev, &uc_snap, &mc_snap);
netif_addr_lock_bh(dev);
netif_addr_lists_reconcile(dev, &uc_snap, &mc_snap,
&uc_ref, &mc_ref);
netif_addr_unlock_bh(dev);
if (err)
netif_rx_mode_schedule_retry(dev);
else
dev->rx_mode_retry_count = 0;
} else if (ops->ndo_set_rx_mode) {
netif_addr_lock_bh(dev);
ops->ndo_set_rx_mode(dev);
@@ -1350,6 +1384,21 @@ static void netif_rx_mode_queue(struct net_device *dev)
schedule_work(&rx_mode_work);
}
static void netif_rx_mode_retry(struct timer_list *t)
{
struct net_device *dev =
timer_container_of(dev, t, rx_mode_retry_timer);
netif_rx_mode_queue(dev);
}
void netif_rx_mode_init(struct net_device *dev)
{
INIT_LIST_HEAD(&dev->rx_mode_node);
__hw_addr_init(&dev->rx_mode_addr_cache);
timer_setup(&dev->rx_mode_retry_timer, netif_rx_mode_retry, 0);
}
/**
* __dev_set_rx_mode() - upload unicast and multicast address lists to device
* and configure RX filtering.