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net: hold netdev instance lock during ndo_open/ndo_stop

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For the drivers that use shaper API, switch to the mode where
core stack holds the netdev lock. This affects two drivers:

* iavf - already grabs netdev lock in ndo_open/ndo_stop, so mostly
         remove these
* netdevsim - switch to _locked APIs to avoid deadlock

iavf_close diff is a bit confusing, the existing call looks like this:
  iavf_close() {
    netdev_lock()
    ..
    netdev_unlock()
    wait_event_timeout(down_waitqueue)
  }

I change it to the following:
  netdev_lock()
  iavf_close() {
    ..
    netdev_unlock()
    wait_event_timeout(down_waitqueue)
    netdev_lock() // reusing this lock call
  }
  netdev_unlock()

Since I'm reusing existing netdev_lock call, so it looks like I only
add netdev_unlock.

Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Stanislav Fomichev 2025-03-05 08:37:19 -08:00 committed by Jakub Kicinski
parent f130a0cc1b
commit d4c22ec680
5 changed files with 54 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/net/ethernet/intel/iavf/iavf_main.c
View File

@ -4562,22 +4562,21 @@ static int iavf_open(struct net_device *netdev)
struct iavf_adapter *adapter = netdev_priv(netdev);
int err;
netdev_assert_locked(netdev);
if (adapter->flags & IAVF_FLAG_PF_COMMS_FAILED) {
dev_err(&adapter->pdev->dev, "Unable to open device due to PF driver failure.\n");
return -EIO;
}
netdev_lock(netdev);
while (!mutex_trylock(&adapter->crit_lock)) {
/* If we are in __IAVF_INIT_CONFIG_ADAPTER state the crit_lock
* is already taken and iavf_open is called from an upper
* device's notifier reacting on NETDEV_REGISTER event.
* We have to leave here to avoid dead lock.
*/
if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER) {
netdev_unlock(netdev);
if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER)
return -EBUSY;
}
usleep_range(500, 1000);
}
@ -4626,7 +4625,6 @@ static int iavf_open(struct net_device *netdev)
iavf_irq_enable(adapter, true);
mutex_unlock(&adapter->crit_lock);
netdev_unlock(netdev);
return 0;
@ -4639,7 +4637,6 @@ static int iavf_open(struct net_device *netdev)
iavf_free_all_tx_resources(adapter);
err_unlock:
mutex_unlock(&adapter->crit_lock);
netdev_unlock(netdev);
return err;
}
@ -4661,12 +4658,12 @@ static int iavf_close(struct net_device *netdev)
u64 aq_to_restore;
int status;
netdev_lock(netdev);
netdev_assert_locked(netdev);
mutex_lock(&adapter->crit_lock);
if (adapter->state <= __IAVF_DOWN_PENDING) {
mutex_unlock(&adapter->crit_lock);
netdev_unlock(netdev);
return 0;
}
@ -4719,6 +4716,7 @@ static int iavf_close(struct net_device *netdev)
if (!status)
netdev_warn(netdev, "Device resources not yet released\n");
netdev_lock(netdev);
mutex_lock(&adapter->crit_lock);
adapter->aq_required |= aq_to_restore;
mutex_unlock(&adapter->crit_lock);

14
drivers/net/netdevsim/netdev.c
View File

@ -402,7 +402,7 @@ static int nsim_init_napi(struct netdevsim *ns)
for (i = 0; i < dev->num_rx_queues; i++) {
rq = ns->rq[i];
netif_napi_add_config(dev, &rq->napi, nsim_poll, i);
netif_napi_add_config_locked(dev, &rq->napi, nsim_poll, i);
}
for (i = 0; i < dev->num_rx_queues; i++) {
@ -422,7 +422,7 @@ static int nsim_init_napi(struct netdevsim *ns)
}
for (i = 0; i < dev->num_rx_queues; i++)
__netif_napi_del(&ns->rq[i]->napi);
__netif_napi_del_locked(&ns->rq[i]->napi);
return err;
}
@ -452,7 +452,7 @@ static void nsim_enable_napi(struct netdevsim *ns)
struct nsim_rq *rq = ns->rq[i];
netif_queue_set_napi(dev, i, NETDEV_QUEUE_TYPE_RX, &rq->napi);
napi_enable(&rq->napi);
napi_enable_locked(&rq->napi);
}
}
@ -461,6 +461,8 @@ static int nsim_open(struct net_device *dev)
struct netdevsim *ns = netdev_priv(dev);
int err;
netdev_assert_locked(dev);
err = nsim_init_napi(ns);
if (err)
return err;
@ -478,8 +480,8 @@ static void nsim_del_napi(struct netdevsim *ns)
for (i = 0; i < dev->num_rx_queues; i++) {
struct nsim_rq *rq = ns->rq[i];
napi_disable(&rq->napi);
__netif_napi_del(&rq->napi);
napi_disable_locked(&rq->napi);
__netif_napi_del_locked(&rq->napi);
}
synchronize_net();
@ -494,6 +496,8 @@ static int nsim_stop(struct net_device *dev)
struct netdevsim *ns = netdev_priv(dev);
struct netdevsim *peer;
netdev_assert_locked(dev);
netif_carrier_off(dev);
peer = rtnl_dereference(ns->peer);
if (peer)

23
include/linux/netdevice.h
View File

@ -2753,6 +2753,29 @@ static inline void netdev_assert_locked_or_invisible(struct net_device *dev)
netdev_assert_locked(dev);
}
static inline bool netdev_need_ops_lock(struct net_device *dev)
{
bool ret = false;
#if IS_ENABLED(CONFIG_NET_SHAPER)
ret |= !!dev->netdev_ops->net_shaper_ops;
#endif
return ret;
}
static inline void netdev_lock_ops(struct net_device *dev)
{
if (netdev_need_ops_lock(dev))
netdev_lock(dev);
}
static inline void netdev_unlock_ops(struct net_device *dev)
{
if (netdev_need_ops_lock(dev))
netdev_unlock(dev);
}
void netif_napi_set_irq_locked(struct napi_struct *napi, int irq);
static inline void netif_napi_set_irq(struct napi_struct *napi, int irq)

12
net/core/dev.c
View File

@ -1627,6 +1627,8 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
if (ret)
return ret;
netdev_lock_ops(dev);
set_bit(__LINK_STATE_START, &dev->state);
if (ops->ndo_validate_addr)
@ -1646,6 +1648,8 @@ static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
add_device_randomness(dev->dev_addr, dev->addr_len);
}
netdev_unlock_ops(dev);
return ret;
}
@ -1716,11 +1720,19 @@ static void __dev_close_many(struct list_head *head)
* We allow it to be called even after a DETACH hot-plug
* event.
*/
/* TODO: move the lock up before clearing __LINK_STATE_START.
* Generates spurious lockdep warning.
*/
netdev_lock_ops(dev);
if (ops->ndo_stop)
ops->ndo_stop(dev);
netif_set_up(dev, false);
netpoll_poll_enable(dev);
netdev_unlock_ops(dev);
}
}

6
net/core/dev.h
View File

@ -134,9 +134,11 @@ static inline void netif_set_up(struct net_device *dev, bool value)
else
dev->flags &= ~IFF_UP;
netdev_lock(dev);
if (!netdev_need_ops_lock(dev))
netdev_lock(dev);
dev->up = value;
netdev_unlock(dev);
if (!netdev_need_ops_lock(dev))
netdev_unlock(dev);
}
static inline void netif_set_gso_max_size(struct net_device *dev,