@@ -83,6 +83,7 @@ unsigned_int allmulti
bool uc_promisc
unsigned_char nested_level
struct_in_device* ip_ptr read_mostly read_mostly __in_dev_get
+struct hlist_head fib_nh_head
struct_inet6_dev* ip6_ptr read_mostly read_mostly __in6_dev_get
struct_vlan_info* vlan_info
struct_dsa_port* dsa_ptr
@@ -2209,6 +2209,8 @@ struct net_device {
/* Protocol-specific pointers */
struct in_device __rcu *ip_ptr;
+ struct hlist_head fib_nh_head;
+
#if IS_ENABLED(CONFIG_VLAN_8021Q)
struct vlan_info __rcu *vlan_info;
#endif
@@ -56,10 +56,6 @@ static unsigned int fib_info_hash_size;
static unsigned int fib_info_hash_bits;
static unsigned int fib_info_cnt;
-#define DEVINDEX_HASHBITS 8
-#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
-static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
-
/* for_nexthops and change_nexthops only used when nexthop object
* is not set in a fib_info. The logic within can reference fib_nh.
*/
@@ -319,12 +315,9 @@ static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
return 0;
}
-static struct hlist_head *
-fib_info_devhash_bucket(const struct net_device *dev)
+static struct hlist_head *fib_nh_head(struct net_device *dev)
{
- u32 val = net_hash_mix(dev_net(dev)) ^ dev->ifindex;
-
- return &fib_info_devhash[hash_32(val, DEVINDEX_HASHBITS)];
+ return &dev->fib_nh_head;
}
static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
@@ -435,11 +428,11 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev)
struct hlist_head *head;
struct fib_nh *nh;
- head = fib_info_devhash_bucket(dev);
+ head = fib_nh_head(dev);
hlist_for_each_entry_rcu(nh, head, nh_hash) {
- if (nh->fib_nh_dev == dev &&
- nh->fib_nh_gw4 == gw &&
+ DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
+ if (nh->fib_nh_gw4 == gw &&
!(nh->fib_nh_flags & RTNH_F_DEAD)) {
return 0;
}
@@ -1595,7 +1588,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
if (!nexthop_nh->fib_nh_dev)
continue;
- head = fib_info_devhash_bucket(nexthop_nh->fib_nh_dev);
+ head = fib_nh_head(nexthop_nh->fib_nh_dev);
hlist_add_head_rcu(&nexthop_nh->nh_hash, head);
} endfor_nexthops(fi)
}
@@ -1948,12 +1941,12 @@ void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig)
void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
{
- struct hlist_head *head = fib_info_devhash_bucket(dev);
+ struct hlist_head *head = fib_nh_head(dev);
struct fib_nh *nh;
hlist_for_each_entry(nh, head, nh_hash) {
- if (nh->fib_nh_dev == dev)
- fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
+ DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
+ fib_nhc_update_mtu(&nh->nh_common, dev->mtu, orig_mtu);
}
}
@@ -1967,7 +1960,7 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
*/
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
{
- struct hlist_head *head = fib_info_devhash_bucket(dev);
+ struct hlist_head *head = fib_nh_head(dev);
struct fib_info *prev_fi = NULL;
int scope = RT_SCOPE_NOWHERE;
struct fib_nh *nh;
@@ -1981,7 +1974,8 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
int dead;
BUG_ON(!fi->fib_nhs);
- if (nh->fib_nh_dev != dev || fi == prev_fi)
+ DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
+ if (fi == prev_fi)
continue;
prev_fi = fi;
dead = 0;
@@ -2131,7 +2125,7 @@ int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
}
prev_fi = NULL;
- head = fib_info_devhash_bucket(dev);
+ head = fib_nh_head(dev);
ret = 0;
hlist_for_each_entry(nh, head, nh_hash) {
@@ -2139,7 +2133,8 @@ int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
int alive;
BUG_ON(!fi->fib_nhs);
- if (nh->fib_nh_dev != dev || fi == prev_fi)
+ DEBUG_NET_WARN_ON_ONCE(nh->fib_nh_dev != dev);
+ if (fi == prev_fi)
continue;
prev_fi = fi;
Upcoming per-netns RTNL conversion needs to get rid of shared hash tables. fib_info_devhash[] is one of them. It is unclear why we used a hash table, because a single hlist_head per net device was cheaper and scalable. Signed-off-by: Eric Dumazet <edumazet@google.com> --- .../networking/net_cachelines/net_device.rst | 1 + include/linux/netdevice.h | 2 ++ net/ipv4/fib_semantics.c | 35 ++++++++----------- 3 files changed, 18 insertions(+), 20 deletions(-)