From: Kuniyuki Iwashima Date: Fri, 16 May 2025 02:27:21 +0000 (-0700) Subject: Revert "ipv6: Factorise ip6_route_multipath_add()." X-Git-Tag: v6.16-rc1~132^2~64^2~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5e4a8cc7beb8567293e6d4230b14e95167759214;p=thirdparty%2Fkernel%2Flinux.git Revert "ipv6: Factorise ip6_route_multipath_add()." Commit 71c0efb6d12f ("ipv6: Factorise ip6_route_multipath_add().") split a loop in ip6_route_multipath_add() so that we can put rcu_read_lock() between ip6_route_info_create() and ip6_route_info_create_nh(). We no longer need to do so as ip6_route_info_create_nh() does not require RCU now. Let's revert the commit to simplify the code. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250516022759.44392-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a87091dd06b1b..96ae21da9961d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5335,131 +5335,29 @@ struct rt6_nh { struct fib6_info *fib6_info; struct fib6_config r_cfg; struct list_head list; - int weight; }; -static void ip6_route_mpath_info_cleanup(struct list_head *rt6_nh_list) +static int ip6_route_info_append(struct list_head *rt6_nh_list, + struct fib6_info *rt, + struct fib6_config *r_cfg) { - struct rt6_nh *nh, *nh_next; + struct rt6_nh *nh; - list_for_each_entry_safe(nh, nh_next, rt6_nh_list, list) { - struct fib6_info *rt = nh->fib6_info; - - if (rt) { - free_percpu(rt->fib6_nh->nh_common.nhc_pcpu_rth_output); - free_percpu(rt->fib6_nh->rt6i_pcpu); - ip_fib_metrics_put(rt->fib6_metrics); - kfree(rt); - } - - list_del(&nh->list); - kfree(nh); + list_for_each_entry(nh, rt6_nh_list, list) { + /* check if fib6_info already exists */ + if (rt6_duplicate_nexthop(nh->fib6_info, rt)) + return -EEXIST; } -} - -static int ip6_route_mpath_info_create(struct list_head *rt6_nh_list, - struct fib6_config *cfg, - struct netlink_ext_ack *extack) -{ - struct rtnexthop *rtnh; - int remaining; - int err; - - remaining = cfg->fc_mp_len; - rtnh = (struct rtnexthop *)cfg->fc_mp; - - /* Parse a Multipath Entry and build a list (rt6_nh_list) of - * fib6_info structs per nexthop - */ - while (rtnh_ok(rtnh, remaining)) { - struct fib6_config r_cfg; - struct fib6_info *rt; - struct rt6_nh *nh; - int attrlen; - - nh = kzalloc(sizeof(*nh), GFP_KERNEL); - if (!nh) { - err = -ENOMEM; - goto err; - } - list_add_tail(&nh->list, rt6_nh_list); - - memcpy(&r_cfg, cfg, sizeof(*cfg)); - if (rtnh->rtnh_ifindex) - r_cfg.fc_ifindex = rtnh->rtnh_ifindex; - - attrlen = rtnh_attrlen(rtnh); - if (attrlen > 0) { - struct nlattr *nla, *attrs = rtnh_attrs(rtnh); - - nla = nla_find(attrs, attrlen, RTA_GATEWAY); - if (nla) { - r_cfg.fc_gateway = nla_get_in6_addr(nla); - r_cfg.fc_flags |= RTF_GATEWAY; - } - - r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); - nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); - if (nla) - r_cfg.fc_encap_type = nla_get_u16(nla); - } - - r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK); - - rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack); - if (IS_ERR(rt)) { - err = PTR_ERR(rt); - goto err; - } - - nh->fib6_info = rt; - nh->weight = rtnh->rtnh_hops + 1; - memcpy(&nh->r_cfg, &r_cfg, sizeof(r_cfg)); + nh = kzalloc(sizeof(*nh), GFP_KERNEL); + if (!nh) + return -ENOMEM; - rtnh = rtnh_next(rtnh, &remaining); - } + nh->fib6_info = rt; + memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg)); + list_add_tail(&nh->list, rt6_nh_list); return 0; -err: - ip6_route_mpath_info_cleanup(rt6_nh_list); - return err; -} - -static int ip6_route_mpath_info_create_nh(struct list_head *rt6_nh_list, - struct netlink_ext_ack *extack) -{ - struct rt6_nh *nh, *nh_next, *nh_tmp; - LIST_HEAD(tmp); - int err; - - list_for_each_entry_safe(nh, nh_next, rt6_nh_list, list) { - struct fib6_info *rt = nh->fib6_info; - - err = ip6_route_info_create_nh(rt, &nh->r_cfg, extack); - if (err) { - nh->fib6_info = NULL; - goto err; - } - - rt->fib6_nh->fib_nh_weight = nh->weight; - - list_move_tail(&nh->list, &tmp); - - list_for_each_entry(nh_tmp, rt6_nh_list, list) { - /* check if fib6_info already exists */ - if (rt6_duplicate_nexthop(nh_tmp->fib6_info, rt)) { - err = -EEXIST; - goto err; - } - } - } -out: - list_splice(&tmp, rt6_nh_list); - return err; -err: - ip6_route_mpath_info_cleanup(rt6_nh_list); - goto out; } static void ip6_route_mpath_notify(struct fib6_info *rt, @@ -5519,11 +5417,16 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, struct fib6_info *rt_notif = NULL, *rt_last = NULL; struct nl_info *info = &cfg->fc_nlinfo; struct rt6_nh *nh, *nh_safe; + struct fib6_config r_cfg; + struct rtnexthop *rtnh; LIST_HEAD(rt6_nh_list); struct rt6_nh *err_nh; + struct fib6_info *rt; __u16 nlflags; - int nhn = 0; + int remaining; + int attrlen; int replace; + int nhn = 0; int err; replace = (cfg->fc_nlinfo.nlh && @@ -5533,13 +5436,57 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND) nlflags |= NLM_F_APPEND; - err = ip6_route_mpath_info_create(&rt6_nh_list, cfg, extack); - if (err) - return err; + remaining = cfg->fc_mp_len; + rtnh = (struct rtnexthop *)cfg->fc_mp; - err = ip6_route_mpath_info_create_nh(&rt6_nh_list, extack); - if (err) - goto cleanup; + /* Parse a Multipath Entry and build a list (rt6_nh_list) of + * fib6_info structs per nexthop + */ + while (rtnh_ok(rtnh, remaining)) { + memcpy(&r_cfg, cfg, sizeof(*cfg)); + if (rtnh->rtnh_ifindex) + r_cfg.fc_ifindex = rtnh->rtnh_ifindex; + + attrlen = rtnh_attrlen(rtnh); + if (attrlen > 0) { + struct nlattr *nla, *attrs = rtnh_attrs(rtnh); + + nla = nla_find(attrs, attrlen, RTA_GATEWAY); + if (nla) { + r_cfg.fc_gateway = nla_get_in6_addr(nla); + r_cfg.fc_flags |= RTF_GATEWAY; + } + + r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); + nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); + if (nla) + r_cfg.fc_encap_type = nla_get_u16(nla); + } + + r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK); + rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + goto cleanup; + } + + err = ip6_route_info_create_nh(rt, &r_cfg, extack); + if (err) { + rt = NULL; + goto cleanup; + } + + rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1; + + err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg); + if (err) { + fib6_info_release(rt); + goto cleanup; + } + + rtnh = rtnh_next(rtnh, &remaining); + } /* for add and replace send one notification with all nexthops. * Skip the notification in fib6_add_rt2node and send one with