nexthop: Factor out hash threshold fdb nexthop selection

The loop in nexthop_select_path_hthr() includes code to check for neighbor
validity. Since this does not apply to fdb nexthops, simplify the loop by
moving the fdb nexthop selection to its own function.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230719-nh_select-v2-1-04383e89f868@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index f95142e..27089de 100644 (file)
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -1152,11 +1152,31 @@ static bool ipv4_good_nh(const struct fib_nh *nh)
        return !!(state & NUD_VALID);
 }
 
+static struct nexthop *nexthop_select_path_fdb(struct nh_group *nhg, int hash)
+{
+       int i;
+
+       for (i = 0; i < nhg->num_nh; i++) {
+               struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+               if (hash > atomic_read(&nhge->hthr.upper_bound))
+                       continue;
+
+               return nhge->nh;
+       }
+
+       WARN_ON_ONCE(1);
+       return NULL;
+}
+
 static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
 {
        struct nexthop *rc = NULL;
        int i;
 
+       if (nhg->fdb_nh)
+               return nexthop_select_path_fdb(nhg, hash);
+
        for (i = 0; i < nhg->num_nh; ++i) {
                struct nh_grp_entry *nhge = &nhg->nh_entries[i];
                struct nh_info *nhi;
@@ -1165,8 +1185,6 @@ static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
                        continue;
 
                nhi = rcu_dereference(nhge->nh->nh_info);
-               if (nhi->fdb_nh)
-                       return nhge->nh;
 
                /* nexthops always check if it is good and does
                 * not rely on a sysctl for this behavior