diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-10-04 13:47:18 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-10-07 16:38:58 -0700 |
| commit | fc38b28365e5f1396209d2878a34065468765087 (patch) | |
| tree | 726d3e346836d55f05e5e2a1c54aae425fa9aee6 | |
| parent | 8a0f62fdeb9ea66ad3d0e959c7c4addbabeac1be (diff) | |
ipv4: use rcu in ip_fib_check_default()
fib_info_devhash[] is not resized in fib_info_hash_move().
fib_nh structs are already freed after an rcu grace period.
This will allow to remove fib_info_lock in the following patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241004134720.579244-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/fib_semantics.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 1219d1b32591..e0ffb4ffd95d 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -275,7 +275,7 @@ void fib_release_info(struct fib_info *fi) change_nexthops(fi) { if (!nexthop_nh->fib_nh_dev) continue; - hlist_del(&nexthop_nh->nh_hash); + hlist_del_rcu(&nexthop_nh->nh_hash); } endfor_nexthops(fi) } /* Paired with READ_ONCE() from fib_table_lookup() */ @@ -431,28 +431,23 @@ static struct fib_info *fib_find_info(struct fib_info *nfi) } /* Check, that the gateway is already configured. - * Used only by redirect accept routine. + * Used only by redirect accept routine, under rcu_read_lock(); */ int ip_fib_check_default(__be32 gw, struct net_device *dev) { struct hlist_head *head; struct fib_nh *nh; - spin_lock(&fib_info_lock); - head = fib_info_devhash_bucket(dev); - hlist_for_each_entry(nh, head, nh_hash) { + hlist_for_each_entry_rcu(nh, head, nh_hash) { if (nh->fib_nh_dev == dev && nh->fib_nh_gw4 == gw && !(nh->fib_nh_flags & RTNH_F_DEAD)) { - spin_unlock(&fib_info_lock); return 0; } } - spin_unlock(&fib_info_lock); - return -1; } @@ -1606,7 +1601,7 @@ link_it: if (!nexthop_nh->fib_nh_dev) continue; head = fib_info_devhash_bucket(nexthop_nh->fib_nh_dev); - hlist_add_head(&nexthop_nh->nh_hash, head); + hlist_add_head_rcu(&nexthop_nh->nh_hash, head); } endfor_nexthops(fi) } spin_unlock_bh(&fib_info_lock); |