ipv4: fib: Namespacify fib_info hash tables.

We will convert RTM_NEWROUTE and RTM_DELROUTE to per-netns RTNL.
Then, we need to have per-netns hash tables for struct fib_info.

Let's allocate the hash tables per netns.

fib_info_hash, fib_info_hash_bits, and fib_info_cnt are now moved
to struct netns_ipv4 and accessed with net->ipv4.fib_XXX.

Also, the netns checks are removed from fib_find_info_nh() and
fib_find_info().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250228042328.96624-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 45ac125e8aebb99d4083d540c907f0d560dac0b0..650b2dc9199f47f6fb139ca20fcc31a80edec6a1 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -111,6 +111,9 @@ struct netns_ipv4 {
 #endif
        struct hlist_head       *fib_table_hash;
        struct sock             *fibnl;
+       struct hlist_head       *fib_info_hash;
+       unsigned int            fib_info_hash_bits;
+       unsigned int            fib_info_cnt;
 
        struct sock             *mc_autojoin_sk;
 

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 0cd40ff18d8be3b679678c3cad02b69946c393f4..f68bb9e34c34ce79c01a77a60de0940e8add07e2 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -50,10 +50,6 @@
 
 #include "fib_lookup.h"
 
-static struct hlist_head *fib_info_hash;
-static unsigned int fib_info_hash_bits;
-static unsigned int fib_info_cnt;
-
 /* for_nexthops and change_nexthops only used when nexthop object
  * is not set in a fib_info. The logic within can reference fib_nh.
  */
@@ -256,8 +252,7 @@ void fib_release_info(struct fib_info *fi)
        ASSERT_RTNL();
        if (fi && refcount_dec_and_test(&fi->fib_treeref)) {
                hlist_del(&fi->fib_hash);
-
-               fib_info_cnt--;
+               fi->fib_net->ipv4.fib_info_cnt--;
 
                if (fi->fib_prefsrc)
                        hlist_del(&fi->fib_lhash);
@@ -333,11 +328,12 @@ static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
 static unsigned int fib_info_hashfn_result(const struct net *net,
                                           unsigned int val)
 {
-       return hash_32(val ^ net_hash_mix(net), fib_info_hash_bits);
+       return hash_32(val ^ net_hash_mix(net), net->ipv4.fib_info_hash_bits);
 }
 
 static struct hlist_head *fib_info_hash_bucket(struct fib_info *fi)
 {
+       struct net *net = fi->fib_net;
        unsigned int val;
 
        val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
@@ -352,16 +348,18 @@ static struct hlist_head *fib_info_hash_bucket(struct fib_info *fi)
                } endfor_nexthops(fi)
        }
 
-       return &fib_info_hash[fib_info_hashfn_result(fi->fib_net, val)];
+       return &net->ipv4.fib_info_hash[fib_info_hashfn_result(net, val)];
 }
 
 static struct hlist_head *fib_info_laddrhash_bucket(const struct net *net,
                                                    __be32 val)
 {
-       u32 slot = hash_32(net_hash_mix(net) ^ (__force u32)val,
-                          fib_info_hash_bits);
+       unsigned int hash_bits = net->ipv4.fib_info_hash_bits;
+       u32 slot;
 
-       return &fib_info_hash[(1 << fib_info_hash_bits) + slot];
+       slot = hash_32(net_hash_mix(net) ^ (__force u32)val, hash_bits);
+
+       return &net->ipv4.fib_info_hash[(1 << hash_bits) + slot];
 }
 
 static struct hlist_head *fib_info_hash_alloc(unsigned int hash_bits)
@@ -376,22 +374,22 @@ static void fib_info_hash_free(struct hlist_head *head)
        kvfree(head);
 }
 
-static void fib_info_hash_grow(void)
+static void fib_info_hash_grow(struct net *net)
 {
+       unsigned int old_size = 1 << net->ipv4.fib_info_hash_bits;
        struct hlist_head *new_info_hash, *old_info_hash;
-       unsigned int old_size = 1 << fib_info_hash_bits;
        unsigned int i;
 
-       if (fib_info_cnt < old_size)
+       if (net->ipv4.fib_info_cnt < old_size)
                return;
 
-       new_info_hash = fib_info_hash_alloc(fib_info_hash_bits + 1);
+       new_info_hash = fib_info_hash_alloc(net->ipv4.fib_info_hash_bits + 1);
        if (!new_info_hash)
                return;
 
-       old_info_hash = fib_info_hash;
-       fib_info_hash = new_info_hash;
-       fib_info_hash_bits += 1;
+       old_info_hash = net->ipv4.fib_info_hash;
+       net->ipv4.fib_info_hash = new_info_hash;
+       net->ipv4.fib_info_hash_bits += 1;
 
        for (i = 0; i < old_size; i++) {
                struct hlist_head *head = &old_info_hash[i];
@@ -429,13 +427,12 @@ static struct fib_info *fib_find_info_nh(struct net *net,
                                 (__force u32)cfg->fc_prefsrc,
                                 cfg->fc_priority);
        hash = fib_info_hashfn_result(net, hash);
-       head = &fib_info_hash[hash];
+       head = &net->ipv4.fib_info_hash[hash];
 
        hlist_for_each_entry(fi, head, fib_hash) {
-               if (!net_eq(fi->fib_net, net))
-                       continue;
                if (!fi->nh || fi->nh->id != cfg->fc_nh_id)
                        continue;
+
                if (cfg->fc_protocol == fi->fib_protocol &&
                    cfg->fc_scope == fi->fib_scope &&
                    cfg->fc_prefsrc == fi->fib_prefsrc &&
@@ -455,10 +452,9 @@ static struct fib_info *fib_find_info(struct fib_info *nfi)
        struct fib_info *fi;
 
        hlist_for_each_entry(fi, head, fib_hash) {
-               if (!net_eq(fi->fib_net, nfi->fib_net))
-                       continue;
                if (fi->fib_nhs != nfi->fib_nhs)
                        continue;
+
                if (nfi->fib_protocol == fi->fib_protocol &&
                    nfi->fib_scope == fi->fib_scope &&
                    nfi->fib_prefsrc == fi->fib_prefsrc &&
@@ -1406,7 +1402,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
        }
 #endif
 
-       fib_info_hash_grow();
+       fib_info_hash_grow(net);
 
        fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);
        if (!fi) {
@@ -1550,7 +1546,7 @@ link_it:
        refcount_set(&fi->fib_treeref, 1);
        refcount_set(&fi->fib_clntref, 1);
 
-       fib_info_cnt++;
+       net->ipv4.fib_info_cnt++;
        hlist_add_head(&fi->fib_hash, fib_info_hash_bucket(fi));
 
        if (fi->fib_prefsrc) {
@@ -2241,22 +2237,17 @@ int __net_init fib4_semantics_init(struct net *net)
 {
        unsigned int hash_bits = 4;
 
-       if (!net_eq(net, &init_net))
-               return 0;
-
-       fib_info_hash = fib_info_hash_alloc(hash_bits);
-       if (!fib_info_hash)
+       net->ipv4.fib_info_hash = fib_info_hash_alloc(hash_bits);
+       if (!net->ipv4.fib_info_hash)
                return -ENOMEM;
 
-       fib_info_hash_bits = hash_bits;
+       net->ipv4.fib_info_hash_bits = hash_bits;
+       net->ipv4.fib_info_cnt = 0;
 
        return 0;
 }
 
 void __net_exit fib4_semantics_exit(struct net *net)
 {
-       if (!net_eq(net, &init_net))
-               return;
-
-       fib_info_hash_free(fib_info_hash);
+       fib_info_hash_free(net->ipv4.fib_info_hash);
 }