| Message ID | 20250311144026.4154277-3-sdf@fomichev.me (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 10eef096be25f3811ada2b43b108d1b8d8170001 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: remove rtnl_lock from the callers of queue APIs | expand |
On Tue, Mar 11, 2025 at 7:40 AM Stanislav Fomichev <sdf@fomichev.me> wrote: > > As we move away from rtnl_lock for queue ops, introduce > per-netdev_nl_sock lock. > > Cc: Mina Almasry <almasrymina@google.com> > Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> > --- > include/net/netdev_netlink.h | 1 + > net/core/netdev-genl.c | 6 ++++++ > 2 files changed, 7 insertions(+) > > diff --git a/include/net/netdev_netlink.h b/include/net/netdev_netlink.h > index 1599573d35c9..075962dbe743 100644 > --- a/include/net/netdev_netlink.h > +++ b/include/net/netdev_netlink.h > @@ -5,6 +5,7 @@ > #include <linux/list.h> > > struct netdev_nl_sock { > + struct mutex lock; > struct list_head bindings; > }; > > diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c > index a219be90c739..63e10717efc5 100644 > --- a/net/core/netdev-genl.c > +++ b/net/core/netdev-genl.c > @@ -859,6 +859,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) > goto err_genlmsg_free; > } > > + mutex_lock(&priv->lock); You do not need to acquire this lock so early, no? AFAICT you only need to lock around: list_add(&binding->list, sock_binding_list); Or is this to establish a locking order (sock_binding_list lock before the netdev lock)?
On 03/11, Mina Almasry wrote: > On Tue, Mar 11, 2025 at 7:40 AM Stanislav Fomichev <sdf@fomichev.me> wrote: > > > > As we move away from rtnl_lock for queue ops, introduce > > per-netdev_nl_sock lock. > > > > Cc: Mina Almasry <almasrymina@google.com> > > Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> > > --- > > include/net/netdev_netlink.h | 1 + > > net/core/netdev-genl.c | 6 ++++++ > > 2 files changed, 7 insertions(+) > > > > diff --git a/include/net/netdev_netlink.h b/include/net/netdev_netlink.h > > index 1599573d35c9..075962dbe743 100644 > > --- a/include/net/netdev_netlink.h > > +++ b/include/net/netdev_netlink.h > > @@ -5,6 +5,7 @@ > > #include <linux/list.h> > > > > struct netdev_nl_sock { > > + struct mutex lock; > > struct list_head bindings; > > }; > > > > diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c > > index a219be90c739..63e10717efc5 100644 > > --- a/net/core/netdev-genl.c > > +++ b/net/core/netdev-genl.c > > @@ -859,6 +859,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) > > goto err_genlmsg_free; > > } > > > > + mutex_lock(&priv->lock); > > You do not need to acquire this lock so early, no? AFAICT you only > need to lock around: > > list_add(&binding->list, sock_binding_list); > > Or is this to establish a locking order (sock_binding_list lock before > the netdev lock)? Right, if I acquire it later, I'd have to do the same order in netdev_nl_sock_priv_destroy and it seems to be a bit more complicated to do (since we go over the list of bindings over there).
On Tue, Mar 11, 2025 at 1:03 PM Stanislav Fomichev <stfomichev@gmail.com> wrote: > > On 03/11, Mina Almasry wrote: > > On Tue, Mar 11, 2025 at 7:40 AM Stanislav Fomichev <sdf@fomichev.me> wrote: > > > > > > As we move away from rtnl_lock for queue ops, introduce > > > per-netdev_nl_sock lock. > > > > > > Cc: Mina Almasry <almasrymina@google.com> > > > Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> > > > --- > > > include/net/netdev_netlink.h | 1 + > > > net/core/netdev-genl.c | 6 ++++++ > > > 2 files changed, 7 insertions(+) > > > > > > diff --git a/include/net/netdev_netlink.h b/include/net/netdev_netlink.h > > > index 1599573d35c9..075962dbe743 100644 > > > --- a/include/net/netdev_netlink.h > > > +++ b/include/net/netdev_netlink.h > > > @@ -5,6 +5,7 @@ > > > #include <linux/list.h> > > > > > > struct netdev_nl_sock { > > > + struct mutex lock; > > > struct list_head bindings; > > > }; > > > > > > diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c > > > index a219be90c739..63e10717efc5 100644 > > > --- a/net/core/netdev-genl.c > > > +++ b/net/core/netdev-genl.c > > > @@ -859,6 +859,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) > > > goto err_genlmsg_free; > > > } > > > > > > + mutex_lock(&priv->lock); > > > > You do not need to acquire this lock so early, no? AFAICT you only > > need to lock around: > > > > list_add(&binding->list, sock_binding_list); > > > > Or is this to establish a locking order (sock_binding_list lock before > > the netdev lock)? > > Right, if I acquire it later, I'd have to do the same order > in netdev_nl_sock_priv_destroy and it seems to be a bit more complicated > to do (since we go over the list of bindings over there). Thanks, Reviewed-by: Mina Almasry <almasrymina@google.com>
diff --git a/include/net/netdev_netlink.h b/include/net/netdev_netlink.h index 1599573d35c9..075962dbe743 100644 --- a/include/net/netdev_netlink.h +++ b/include/net/netdev_netlink.h @@ -5,6 +5,7 @@ #include <linux/list.h> struct netdev_nl_sock { + struct mutex lock; struct list_head bindings; }; diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index a219be90c739..63e10717efc5 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -859,6 +859,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) goto err_genlmsg_free; } + mutex_lock(&priv->lock); rtnl_lock(); netdev = __dev_get_by_index(genl_info_net(info), ifindex); @@ -918,6 +919,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unbind; rtnl_unlock(); + mutex_unlock(&priv->lock); return 0; @@ -925,6 +927,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) net_devmem_unbind_dmabuf(binding); err_unlock: rtnl_unlock(); + mutex_unlock(&priv->lock); err_genlmsg_free: nlmsg_free(rsp); return err; @@ -933,6 +936,7 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) void netdev_nl_sock_priv_init(struct netdev_nl_sock *priv) { INIT_LIST_HEAD(&priv->bindings); + mutex_init(&priv->lock); } void netdev_nl_sock_priv_destroy(struct netdev_nl_sock *priv) @@ -940,11 +944,13 @@ void netdev_nl_sock_priv_destroy(struct netdev_nl_sock *priv) struct net_devmem_dmabuf_binding *binding; struct net_devmem_dmabuf_binding *temp; + mutex_lock(&priv->lock); list_for_each_entry_safe(binding, temp, &priv->bindings, list) { rtnl_lock(); net_devmem_unbind_dmabuf(binding); rtnl_unlock(); } + mutex_unlock(&priv->lock); } static int netdev_genl_netdevice_event(struct notifier_block *nb,
As we move away from rtnl_lock for queue ops, introduce per-netdev_nl_sock lock. Cc: Mina Almasry <almasrymina@google.com> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> --- include/net/netdev_netlink.h | 1 + net/core/netdev-genl.c | 6 ++++++ 2 files changed, 7 insertions(+)