| Message ID | 20250114035118.110297-10-kuba@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: use netdev->lock to protect NAPI | expand |
On Tue, Jan 14, 2025 at 4:51 AM Jakub Kicinski <kuba@kernel.org> wrote: > > Take netdev_lock() in netif_napi_set_irq(). All NAPI "control fields" > are now protected by that lock (most of the other ones are set during > napi add/del). The napi_hash_node is fully protected by the hash > spin lock, but close enough for the kdoc... > > Signed-off-by: Jakub Kicinski <kuba@kernel.org> > --- Reviewed-by: Eric Dumazet <edumazet@google.com>
On Mon, Jan 13, 2025 at 07:51:15PM -0800, Jakub Kicinski wrote: > Take netdev_lock() in netif_napi_set_irq(). All NAPI "control fields" > are now protected by that lock (most of the other ones are set during > napi add/del). The napi_hash_node is fully protected by the hash > spin lock, but close enough for the kdoc... > > Signed-off-by: Jakub Kicinski <kuba@kernel.org> > --- > include/linux/netdevice.h | 10 +++++++++- > net/core/dev.c | 2 +- > 2 files changed, 10 insertions(+), 2 deletions(-) Reviewed-by: Joe Damato <jdamato@fastly.com>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 75c30404657b..03eeeac7dbdf 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -388,6 +388,7 @@ struct napi_struct { unsigned long gro_flush_timeout; unsigned long irq_suspend_timeout; u32 defer_hard_irqs; + /* all fields past this point are write-protected by netdev_lock */ /* control-path-only fields follow */ struct list_head dev_list; struct hlist_node napi_hash_node; @@ -2705,11 +2706,18 @@ static inline void netdev_assert_locked_or_invisible(struct net_device *dev) netdev_assert_locked(dev); } -static inline void netif_napi_set_irq(struct napi_struct *napi, int irq) +static inline void netif_napi_set_irq_locked(struct napi_struct *napi, int irq) { napi->irq = irq; } +static inline void netif_napi_set_irq(struct napi_struct *napi, int irq) +{ + netdev_lock(napi->dev); + netif_napi_set_irq_locked(napi, irq); + netdev_unlock(napi->dev); +} + /* Default NAPI poll() weight * Device drivers are strongly advised to not use bigger value */ diff --git a/net/core/dev.c b/net/core/dev.c index 5872f0797cc3..df2a8b54a9f2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6956,7 +6956,7 @@ void netif_napi_add_weight_locked(struct net_device *dev, */ if (dev->threaded && napi_kthread_create(napi)) dev->threaded = false; - netif_napi_set_irq(napi, -1); + netif_napi_set_irq_locked(napi, -1); } EXPORT_SYMBOL(netif_napi_add_weight_locked);
Take netdev_lock() in netif_napi_set_irq(). All NAPI "control fields" are now protected by that lock (most of the other ones are set during napi add/del). The napi_hash_node is fully protected by the hash spin lock, but close enough for the kdoc... Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- include/linux/netdevice.h | 10 +++++++++- net/core/dev.c | 2 +- 2 files changed, 10 insertions(+), 2 deletions(-)