Before this patch we had 3 different fdb searching functions which was confusing. This patch reduces all of them to one - fdb_find_rcu(), and two flavors: br_fdb_find() which requires hash_lock and br_fdb_find_rcu which requires RCU. This makes it clear what needs to be used, we also remove two abusers of __br_fdb_get which called it under hash_lock and replace them with br_fdb_find().
Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com> --- net/bridge/br_device.c | 2 +- net/bridge/br_fdb.c | 113 ++++++++++++++++++++---------------------------- net/bridge/br_input.c | 4 +- net/bridge/br_private.h | 5 ++- 4 files changed, 54 insertions(+), 70 deletions(-) diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index d208ee9ab60a..ea71513fca21 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -79,7 +79,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) br_multicast_flood(mdst, skb, false, true); else br_flood(br, skb, BR_PKT_MULTICAST, false, true); - } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) { + } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) { br_forward(dst->dst, skb, false, true); } else { br_flood(br, skb, BR_PKT_UNICAST, false, true); diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index 5693168e88b6..04a53a0b733d 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -28,9 +28,6 @@ #include "br_private.h" static struct kmem_cache *br_fdb_cache __read_mostly; -static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head, - const unsigned char *addr, - __u16 vid); static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, const unsigned char *addr, u16 vid); static void fdb_notify(struct net_bridge *br, @@ -86,6 +83,43 @@ static void fdb_rcu_free(struct rcu_head *head) kmem_cache_free(br_fdb_cache, ent); } +static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head, + const unsigned char *addr, + __u16 vid) +{ + struct net_bridge_fdb_entry *f; + + hlist_for_each_entry_rcu(f, head, hlist) + if (ether_addr_equal(f->addr.addr, addr) && f->vlan_id == vid) + break; + + return f; +} + +/* requires bridge hash_lock */ +static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br, + const unsigned char *addr, + __u16 vid) +{ + struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; + struct net_bridge_fdb_entry *fdb; + + rcu_read_lock(); + fdb = fdb_find_rcu(head, addr, vid); + rcu_read_unlock(); + + return fdb; +} + +struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br, + const unsigned char *addr, + __u16 vid) +{ + struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; + + return fdb_find_rcu(head, addr, vid); +} + /* When a static FDB entry is added, the mac address from the entry is * added to the bridge private HW address list and all required ports * are then updated with the new information. @@ -198,11 +232,10 @@ void br_fdb_find_delete_local(struct net_bridge *br, const struct net_bridge_port *p, const unsigned char *addr, u16 vid) { - struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *f; spin_lock_bh(&br->hash_lock); - f = fdb_find(head, addr, vid); + f = br_fdb_find(br, addr, vid); if (f && f->is_local && !f->added_by_user && f->dst == p) fdb_delete_local(br, p, f); spin_unlock_bh(&br->hash_lock); @@ -266,7 +299,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) spin_lock_bh(&br->hash_lock); /* If old entry was unassociated with any port, then delete it. */ - f = __br_fdb_get(br, br->dev->dev_addr, 0); + f = br_fdb_find(br, br->dev->dev_addr, 0); if (f && f->is_local && !f->dst && !f->added_by_user) fdb_delete_local(br, NULL, f); @@ -281,7 +314,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) list_for_each_entry(v, &vg->vlan_list, vlist) { if (!br_vlan_should_use(v)) continue; - f = __br_fdb_get(br, br->dev->dev_addr, v->vid); + f = br_fdb_find(br, br->dev->dev_addr, v->vid); if (f && f->is_local && !f->dst && !f->added_by_user) fdb_delete_local(br, NULL, f); fdb_insert(br, NULL, newaddr, v->vid); @@ -380,24 +413,6 @@ void br_fdb_delete_by_port(struct net_bridge *br, spin_unlock_bh(&br->hash_lock); } -/* No locking or refcounting, assumes caller has rcu_read_lock */ -struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, - const unsigned char *addr, - __u16 vid) -{ - struct net_bridge_fdb_entry *fdb; - - hlist_for_each_entry_rcu(fdb, - &br->hash[br_mac_hash(addr, vid)], hlist) { - if (ether_addr_equal(fdb->addr.addr, addr) && - fdb->vlan_id == vid) { - return fdb; - } - } - - return NULL; -} - #if IS_ENABLED(CONFIG_ATM_LANE) /* Interface used by ATM LANE hook to test * if an addr is on some other bridge port */ @@ -412,7 +427,7 @@ int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) if (!port) ret = 0; else { - fdb = __br_fdb_get(port->br, addr, 0); + fdb = br_fdb_find_rcu(port->br, addr, 0); ret = fdb && fdb->dst && fdb->dst->dev != dev && fdb->dst->state == BR_STATE_FORWARDING; } @@ -474,34 +489,6 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf, return num; } -static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head, - const unsigned char *addr, - __u16 vid) -{ - struct net_bridge_fdb_entry *fdb; - - hlist_for_each_entry(fdb, head, hlist) { - if (ether_addr_equal(fdb->addr.addr, addr) && - fdb->vlan_id == vid) - return fdb; - } - return NULL; -} - -static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head, - const unsigned char *addr, - __u16 vid) -{ - struct net_bridge_fdb_entry *fdb; - - hlist_for_each_entry_rcu(fdb, head, hlist) { - if (ether_addr_equal(fdb->addr.addr, addr) && - fdb->vlan_id == vid) - return fdb; - } - return NULL; -} - static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, struct net_bridge_port *source, const unsigned char *addr, @@ -535,7 +522,7 @@ static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, if (!is_valid_ether_addr(addr)) return -EINVAL; - fdb = fdb_find(head, addr, vid); + fdb = br_fdb_find(br, addr, vid); if (fdb) { /* it is okay to have multiple ports with same * address, just use the first one. @@ -608,7 +595,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, } } else { spin_lock(&br->hash_lock); - if (likely(!fdb_find(head, addr, vid))) { + if (likely(!fdb_find_rcu(head, addr, vid))) { fdb = fdb_create(head, source, addr, vid, 0, 0); if (fdb) { if (unlikely(added_by_user)) @@ -792,7 +779,7 @@ static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, return -EINVAL; } - fdb = fdb_find(head, addr, vid); + fdb = br_fdb_find(br, addr, vid); if (fdb == NULL) { if (!(flags & NLM_F_CREATE)) return -ENOENT; @@ -942,10 +929,9 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr, u16 vid) { - struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)]; struct net_bridge_fdb_entry *fdb; - fdb = fdb_find(head, addr, vid); + fdb = br_fdb_find(br, addr, vid); if (!fdb) return -ENOENT; @@ -969,10 +955,9 @@ static int fdb_delete_by_addr_and_port(struct net_bridge_port *p, const u8 *addr, u16 vlan) { struct net_bridge *br = p->br; - struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan)]; struct net_bridge_fdb_entry *fdb; - fdb = fdb_find(head, addr, vlan); + fdb = br_fdb_find(br, addr, vlan); if (!fdb || fdb->dst != p) return -ENOENT; @@ -1117,7 +1102,7 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, spin_lock_bh(&br->hash_lock); head = &br->hash[br_mac_hash(addr, vid)]; - fdb = fdb_find(head, addr, vid); + fdb = br_fdb_find(br, addr, vid); if (!fdb) { fdb = fdb_create(head, p, addr, vid, 0, 0); if (!fdb) { @@ -1145,15 +1130,13 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p, const unsigned char *addr, u16 vid) { - struct hlist_head *head; struct net_bridge_fdb_entry *fdb; int err = 0; ASSERT_RTNL(); spin_lock_bh(&br->hash_lock); - head = &br->hash[br_mac_hash(addr, vid)]; - fdb = fdb_find(head, addr, vid); + fdb = br_fdb_find(br, addr, vid); if (fdb && fdb->added_by_external_learn) fdb_delete(br, fdb); else diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 4615a9b3e26c..236f34244dbe 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -114,7 +114,7 @@ static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, return; } - f = __br_fdb_get(br, n->ha, vid); + f = br_fdb_find_rcu(br, n->ha, vid); if (f && ((p->flags & BR_PROXYARP) || (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) { arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip, @@ -189,7 +189,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb } break; case BR_PKT_UNICAST: - dst = __br_fdb_get(br, dest, vid); + dst = br_fdb_find_rcu(br, dest, vid); default: break; } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 1cbbf63a5ef7..61368186edea 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -507,8 +507,9 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr); void br_fdb_cleanup(struct work_struct *work); void br_fdb_delete_by_port(struct net_bridge *br, const struct net_bridge_port *p, u16 vid, int do_all); -struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br, - const unsigned char *addr, __u16 vid); +struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br, + const unsigned char *addr, + __u16 vid); int br_fdb_test_addr(struct net_device *dev, unsigned char *addr); int br_fdb_fillbuf(struct net_bridge *br, void *buf, unsigned long count, unsigned long off); -- 2.1.4