[RFC PATCH 02/13] nexthop: __nh_notifier_single_info_init(): Make nh_info an argument
From: Petr Machata <petrm@nvidia.com>
Date: 2021-02-08 20:47:02
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
The cited function currently uses rtnl_dereference() to get nh_info from a handed-in nexthop. However, under the resilient hashing scheme, this function will not always be called under RTNL, sometimes the mutual exclusion will be achieved differently. Therefore move the nh_info extraction from the function to its callers to make it possible to use a different synchronization guarantee. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> --- net/ipv4/nexthop.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 5fc2ddc5d43c..7b687bca0b87 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c@@ -52,10 +52,8 @@ static bool nexthop_notifiers_is_empty(struct net *net) static void __nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info, - const struct nexthop *nh) + const struct nh_info *nhi) { - struct nh_info *nhi = rtnl_dereference(nh->nh_info); - nh_info->dev = nhi->fib_nhc.nhc_dev; nh_info->gw_family = nhi->fib_nhc.nhc_gw_family; if (nh_info->gw_family == AF_INET)
@@ -71,12 +69,14 @@ __nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info, static int nh_notifier_single_info_init(struct nh_notifier_info *info, const struct nexthop *nh) { + struct nh_info *nhi = rtnl_dereference(nh->nh_info); + info->type = NH_NOTIFIER_INFO_TYPE_SINGLE; info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL); if (!info->nh) return -ENOMEM; - __nh_notifier_single_info_init(info->nh, nh); + __nh_notifier_single_info_init(info->nh, nhi); return 0; }
@@ -103,11 +103,13 @@ static int nh_notifier_mp_info_init(struct nh_notifier_info *info, for (i = 0; i < num_nh; i++) { struct nh_grp_entry *nhge = &nhg->nh_entries[i]; + struct nh_info *nhi; + nhi = rtnl_dereference(nhge->nh->nh_info); info->nh_grp->nh_entries[i].id = nhge->nh->id; info->nh_grp->nh_entries[i].weight = nhge->weight; __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh, - nhge->nh); + nhi); } return 0;
--
2.26.2