ipv4: fib: Remove fib_info_laddrhash pointer.

We will allocate the fib_info hash tables per netns.

There are 5 global variables for fib_info hash tables:
fib_info_hash, fib_info_laddrhash, fib_info_hash_size,
fib_info_hash_bits, fib_info_cnt.

However, fib_info_laddrhash and fib_info_hash_size can be
easily calculated from fib_info_hash and fib_info_hash_bits.

Let's remove the fib_info_laddrhash pointer and instead use
fib_info_hash + (1 << fib_info_hash_bits).

While at it, fib_info_laddrhash_bucket() is moved near other
hash-table-specific functions.

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/20250228042328.96624-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 54749dd7afc8a54058299e1852cfa5a59af31264..6cc518dd665f9c48a8e6d528c323b61ab442705a 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -51,7 +51,6 @@
 #include "fib_lookup.h"
 
 static struct hlist_head *fib_info_hash;
-static struct hlist_head *fib_info_laddrhash;
 static unsigned int fib_info_hash_size;
 static unsigned int fib_info_hash_bits;
 static unsigned int fib_info_cnt;
@@ -357,6 +356,15 @@ static struct hlist_head *fib_info_hash_bucket(struct fib_info *fi)
        return &fib_info_hash[fib_info_hashfn_result(fi->fib_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);
+
+       return &fib_info_hash[(1 << fib_info_hash_bits) + slot];
+}
+
 static struct hlist_head *fib_info_hash_alloc(unsigned int hash_bits)
 {
        /* The second half is used for prefsrc */
@@ -1247,26 +1255,15 @@ int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope,
        return err;
 }
 
-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);
-
-       return &fib_info_laddrhash[slot];
-}
-
 static void fib_info_hash_move(struct hlist_head *new_info_hash,
                               unsigned int new_size)
 {
-       struct hlist_head *new_laddrhash = new_info_hash + new_size;
-       struct hlist_head *old_info_hash, *old_laddrhash;
        unsigned int old_size = fib_info_hash_size;
+       struct hlist_head *old_info_hash;
        unsigned int i;
 
        ASSERT_RTNL();
        old_info_hash = fib_info_hash;
-       old_laddrhash = fib_info_laddrhash;
        fib_info_hash_size = new_size;
        fib_info_hash_bits = ilog2(new_size);
        fib_info_hash = new_info_hash;
@@ -1280,9 +1277,8 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
                        hlist_add_head(&fi->fib_hash, fib_info_hash_bucket(fi));
        }
 
-       fib_info_laddrhash = new_laddrhash;
        for (i = 0; i < old_size; i++) {
-               struct hlist_head *lhead = &old_laddrhash[i];
+               struct hlist_head *lhead = &old_info_hash[old_size + i];
                struct hlist_node *n;
                struct fib_info *fi;
 
@@ -2261,7 +2257,6 @@ int __net_init fib4_semantics_init(struct net *net)
 
        fib_info_hash_bits = hash_bits;
        fib_info_hash_size = 1 << hash_bits;
-       fib_info_laddrhash = fib_info_hash + fib_info_hash_size;
 
        return 0;
 }