[PATCH v3 net-next 02/11] net: bridge: offload all port flags at once in br_setport

Vladimir Oltean
2021-02-10T09:24:24Z

From: Vladimir Oltean <vladimir.oltean@nxp.com>

If for example this command:

ip link set swp0 type bridge_slave flood off mcast_flood off learning off

succeeded at configuring BR_FLOOD and BR_MCAST_FLOOD but not at
BR_LEARNING, there would be no attempt to revert the partial state in
any way. Arguably, if the user changes more than one flag through the
same netlink command, this one _should_ be all or nothing, which means
it should be passed through switchdev as all or nothing.

We also move the br->lock handling inside br_setport in anticipation of
a future patch which will temporarily drop the lock around
br_switchdev_set_port_flag, since we would like that switchdev
notification to be emitted in blocking context.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Changes in v3:
Don't attempt to drop br->lock around br_switchdev_set_port_flag now,
move that part to a later patch.

Changes in v2:
Patch is new.

Changes in v2:
Patch is new.

net/bridge/br_netlink.c | 145 ++++++++++++++------------------------
net/bridge/br_switchdev.c | 7 +-
2 files changed, 58 insertions(+), 94 deletions(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index bd3962da345a..4e64775bd8fb 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -853,103 +853,76 @@ static int br_set_port_state(struct net_bridge_port *p, u8 state)
}

/* Set/clear or port flags based on attribute */
-static int br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
- int attrtype, unsigned long mask)
+static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
+ int attrtype, unsigned long mask)
{
- unsigned long flags;
- int err;
-
if (!tb[attrtype])
- return 0;
+ return;

if (nla_get_u8(tb[attrtype]))
- flags = p->flags | mask;
+ p->flags |= mask;
else
- flags = p->flags & ~mask;
-
- err = br_switchdev_set_port_flag(p, flags, mask);
- if (err)
- return err;
-
- p->flags = flags;
- return 0;
+ p->flags &= ~mask;
}

/* Process bridge protocol info on port */
static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
{
- unsigned long old_flags = p->flags;
- bool br_vlan_tunnel_old = false;
+ unsigned long old_flags, changed_mask;
+ bool br_vlan_tunnel_old;
int err;

- err = br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
- if (err)
- return err;
+ spin_lock_bh(&p->br->lock);

- err = br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
- if (err)
- return err;
+ old_flags = p->flags;
+ br_vlan_tunnel_old = (old_flags & BR_VLAN_TUNNEL) ? true : false;

- err = br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
- if (err)
- return err;
+ br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
+ br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
+ br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE,
+ BR_MULTICAST_FAST_LEAVE);
+ br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
+ br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
+ br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
+ br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_FLOOD, BR_MCAST_FLOOD);
+ br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_TO_UCAST,
+ BR_MULTICAST_TO_UNICAST);
+ br_set_port_flag(p, tb, IFLA_BRPORT_BCAST_FLOOD, BR_BCAST_FLOOD);
+ br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
+ br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
+ br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
+ br_set_port_flag(p, tb, IFLA_BRPORT_NEIGH_SUPPRESS, BR_NEIGH_SUPPRESS);
+ br_set_port_flag(p, tb, IFLA_BRPORT_ISOLATED, BR_ISOLATED);

- err = br_set_port_flag(p, tb, IFLA_BRPORT_PROTECT, BR_ROOT_BLOCK);
- if (err)
- return err;
+ changed_mask = old_flags ^ p->flags;

- err = br_set_port_flag(p, tb, IFLA_BRPORT_LEARNING, BR_LEARNING);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_UNICAST_FLOOD, BR_FLOOD);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_FLOOD, BR_MCAST_FLOOD);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_MCAST_TO_UCAST, BR_MULTICAST_TO_UNICAST);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_BCAST_FLOOD, BR_BCAST_FLOOD);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP, BR_PROXYARP);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_PROXYARP_WIFI, BR_PROXYARP_WIFI);
- if (err)
- return err;
-
- br_vlan_tunnel_old = (p->flags & BR_VLAN_TUNNEL) ? true : false;
- err = br_set_port_flag(p, tb, IFLA_BRPORT_VLAN_TUNNEL, BR_VLAN_TUNNEL);
- if (err)
- return err;
+ err = br_switchdev_set_port_flag(p, p->flags, changed_mask);
+ if (err) {
+ p->flags = old_flags;
+ goto out;
+ }

if (br_vlan_tunnel_old && !(p->flags & BR_VLAN_TUNNEL))
nbp_vlan_tunnel_info_flush(p);

+ br_port_flags_change(p, changed_mask);
+
if (tb[IFLA_BRPORT_COST]) {
err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
if (err)
- return err;
+ goto out;
}

if (tb[IFLA_BRPORT_PRIORITY]) {
err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
if (err)
- return err;
+ goto out;
}

if (tb[IFLA_BRPORT_STATE]) {
err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
if (err)
- return err;
+ goto out;
}

if (tb[IFLA_BRPORT_FLUSH])
@@ -961,7 +934,7 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])

err = br_multicast_set_port_router(p, mcast_router);
if (err)
- return err;
+ goto out;
}

if (tb[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT]) {
@@ -970,27 +943,20 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
hlimit = nla_get_u32(tb[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT]);
err = br_multicast_eht_set_hosts_limit(p, hlimit);
if (err)
- return err;
+ goto out;
}
#endif

if (tb[IFLA_BRPORT_GROUP_FWD_MASK]) {
u16 fwd_mask = nla_get_u16(tb[IFLA_BRPORT_GROUP_FWD_MASK]);

- if (fwd_mask & BR_GROUPFWD_MACPAUSE)
- return -EINVAL;
+ if (fwd_mask & BR_GROUPFWD_MACPAUSE) {
+ err = -EINVAL;
+ goto out;
+ }
p->group_fwd_mask = fwd_mask;
}

- err = br_set_port_flag(p, tb, IFLA_BRPORT_NEIGH_SUPPRESS,
- BR_NEIGH_SUPPRESS);
- if (err)
- return err;
-
- err = br_set_port_flag(p, tb, IFLA_BRPORT_ISOLATED, BR_ISOLATED);
- if (err)
- return err;
-
if (tb[IFLA_BRPORT_BACKUP_PORT]) {
struct net_device *backup_dev = NULL;
u32 backup_ifindex;
@@ -999,17 +965,21 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
if (backup_ifindex) {
backup_dev = __dev_get_by_index(dev_net(p->dev),
backup_ifindex);
- if (!backup_dev)
- return -ENOENT;
+ if (!backup_dev) {
+ err = -ENOENT;
+ goto out;
+ }
}

err = nbp_backup_change(p, backup_dev);
if (err)
- return err;
+ goto out;
}

- br_port_flags_change(p, old_flags ^ p->flags);
- return 0;
+out:
+ spin_unlock_bh(&p->br->lock);
+
+ return err;
}

/* Change state and parameters on port. */
@@ -1045,9 +1015,7 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlh, u16 flags,
if (err)
return err;

- spin_lock_bh(&p->br->lock);
err = br_setport(p, tb);
- spin_unlock_bh(&p->br->lock);
} else {
/* Binary compatibility with old RSTP */
if (nla_len(protinfo) < sizeof(u8))
@@ -1134,17 +1102,10 @@ static int br_port_slave_changelink(struct net_device *brdev,
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
- struct net_bridge *br = netdev_priv(brdev);
- int ret;
-
if (!data)
return 0;

- spin_lock_bh(&br->lock);
- ret = br_setport(br_port_get_rtnl(dev), data);
- spin_unlock_bh(&br->lock);
-
- return ret;
+ return br_setport(br_port_get_rtnl(dev), data);
}

static int br_port_fill_slave_info(struct sk_buff *skb,
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index a9c23ef83443..c004ade25ac0 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -65,16 +65,19 @@ int br_switchdev_set_port_flag(struct net_bridge_port *p,
struct switchdev_attr attr = {
.orig_dev = p->dev,
.id = SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS,
- .u.brport_flags = mask,
};
struct switchdev_notifier_port_attr_info info = {
.attr = &attr,
};
int err;

- if (mask & ~BR_PORT_FLAGS_HW_OFFLOAD)
+ flags &= BR_PORT_FLAGS_HW_OFFLOAD;
+ mask &= BR_PORT_FLAGS_HW_OFFLOAD;
+ if (!mask)
return 0;

+ attr.u.brport_flags = mask;
+
/* We run from atomic context here */
err = call_switchdev_notifiers(SWITCHDEV_PORT_ATTR_SET, p->dev,
&info.info, NULL);
--
2.25.1