diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-10-29 17:33:02 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-11-03 17:40:51 -0800 |
| commit | dde1b38e873cff70f0af36e884bbeb1b14a536ed (patch) | |
| tree | 95515c85771700813d6a58f606d1908714c31bab /net/mpls | |
| parent | 3a49629335a523341d3fae895435d5217341a022 (diff) | |
mpls: Convert mpls_dump_routes() to RCU.
mpls_dump_routes() sets fib_dump_filter.rtnl_held to true and
calls __dev_get_by_index() in mpls_valid_fib_dump_req().
This is the only RTNL dependant in mpls_dump_routes().
Also, synchronize_rcu() in resize_platform_label_table()
guarantees that net->mpls.platform_label is alive under RCU.
Let's convert mpls_dump_routes() to RCU and use dev_get_by_index_rcu().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20251029173344.2934622-11-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mpls')
| -rw-r--r-- | net/mpls/af_mpls.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index 35ae3dbd7bdc..f00f75c137dc 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -2153,7 +2153,7 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, if (i == RTA_OIF) { ifindex = nla_get_u32(tb[i]); - filter->dev = __dev_get_by_index(net, ifindex); + filter->dev = dev_get_by_index_rcu(net, ifindex); if (!filter->dev) return -ENODEV; filter->filter_set = 1; @@ -2191,20 +2191,19 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) struct net *net = sock_net(skb->sk); struct mpls_route __rcu **platform_label; struct fib_dump_filter filter = { - .rtnl_held = true, + .rtnl_held = false, }; unsigned int flags = NLM_F_MULTI; size_t platform_labels; unsigned int index; + int err; - ASSERT_RTNL(); + rcu_read_lock(); if (cb->strict_check) { - int err; - err = mpls_valid_fib_dump_req(net, nlh, &filter, cb); if (err < 0) - return err; + goto err; /* for MPLS, there is only 1 table with fixed type and flags. * If either are set in the filter then return nothing. @@ -2212,14 +2211,14 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) || (filter.rt_type && filter.rt_type != RTN_UNICAST) || filter.flags) - return skb->len; + goto unlock; } index = cb->args[0]; if (index < MPLS_LABEL_FIRST_UNRESERVED) index = MPLS_LABEL_FIRST_UNRESERVED; - platform_label = rtnl_dereference(net->mpls.platform_label); + platform_label = rcu_dereference(net->mpls.platform_label); platform_labels = net->mpls.platform_labels; if (filter.filter_set) @@ -2228,7 +2227,7 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) for (; index < platform_labels; index++) { struct mpls_route *rt; - rt = rtnl_dereference(platform_label[index]); + rt = rcu_dereference(platform_label[index]); if (!rt) continue; @@ -2243,7 +2242,13 @@ static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb) } cb->args[0] = index; +unlock: + rcu_read_unlock(); return skb->len; + +err: + rcu_read_unlock(); + return err; } static inline size_t lfib_nlmsg_size(struct mpls_route *rt) @@ -2767,7 +2772,8 @@ static struct rtnl_af_ops mpls_af_ops __read_mostly = { static const struct rtnl_msg_handler mpls_rtnl_msg_handlers[] __initdata_or_module = { {THIS_MODULE, PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0}, {THIS_MODULE, PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0}, - {THIS_MODULE, PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, 0}, + {THIS_MODULE, PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, + RTNL_FLAG_DUMP_UNLOCKED}, {THIS_MODULE, PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf, mpls_netconf_dump_devconf, RTNL_FLAG_DUMP_UNLOCKED}, |