From e9c5158ac26affd5d8ce006521bdfb7148090e18 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 3 Dec 2009 12:22:55 -0800 Subject: [PATCH] net: Allow fib_rule_unregister to batch Refactor the code so fib_rules_register always takes a template instead of the actual fib_rules_ops structure that will be used. This is required for network namespace support so 2 out of the 3 callers already do this, it allows the error handling to be made common, and it allows fib_rules_unregister to free the template for hte caller. Modify fib_rules_unregister to use call_rcu instead of syncrhonize_rcu to allw multiple namespaces to be cleaned up in the same rcu grace period. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- include/net/fib_rules.h | 3 ++- net/core/fib_rules.c | 36 +++++++++++++++++++++++++++++++++--- net/decnet/dn_rules.c | 22 ++++++++++++---------- net/ipv4/fib_rules.c | 12 +++--------- net/ipv6/fib6_rules.c | 22 +++++++--------------- 5 files changed, 57 insertions(+), 38 deletions(-) diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h index d4e875a58f8..c07ac9650eb 100644 --- a/include/net/fib_rules.h +++ b/include/net/fib_rules.h @@ -66,6 +66,7 @@ struct fib_rules_ops { struct list_head rules_list; struct module *owner; struct net *fro_net; + struct rcu_head rcu; }; #define FRA_GENERIC_POLICY \ @@ -102,7 +103,7 @@ static inline u32 frh_get_table(struct fib_rule_hdr *frh, struct nlattr **nla) return frh->table; } -extern int fib_rules_register(struct fib_rules_ops *); +extern struct fib_rules_ops *fib_rules_register(struct fib_rules_ops *, struct net *); extern void fib_rules_unregister(struct fib_rules_ops *); extern void fib_rules_cleanup_ops(struct fib_rules_ops *); diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index ef0e7d9e664..02a3b2c69c1 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -72,7 +72,7 @@ static void flush_route_cache(struct fib_rules_ops *ops) ops->flush_cache(ops); } -int fib_rules_register(struct fib_rules_ops *ops) +static int __fib_rules_register(struct fib_rules_ops *ops) { int err = -EEXIST; struct fib_rules_ops *o; @@ -102,6 +102,28 @@ errout: return err; } +struct fib_rules_ops * +fib_rules_register(struct fib_rules_ops *tmpl, struct net *net) +{ + struct fib_rules_ops *ops; + int err; + + ops = kmemdup(tmpl, sizeof (*ops), GFP_KERNEL); + if (ops == NULL) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&ops->rules_list); + ops->fro_net = net; + + err = __fib_rules_register(ops); + if (err) { + kfree(ops); + ops = ERR_PTR(err); + } + + return ops; +} + EXPORT_SYMBOL_GPL(fib_rules_register); void fib_rules_cleanup_ops(struct fib_rules_ops *ops) @@ -115,6 +137,15 @@ void fib_rules_cleanup_ops(struct fib_rules_ops *ops) } EXPORT_SYMBOL_GPL(fib_rules_cleanup_ops); +static void fib_rules_put_rcu(struct rcu_head *head) +{ + struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu); + struct net *net = ops->fro_net; + + release_net(net); + kfree(ops); +} + void fib_rules_unregister(struct fib_rules_ops *ops) { struct net *net = ops->fro_net; @@ -124,8 +155,7 @@ void fib_rules_unregister(struct fib_rules_ops *ops) fib_rules_cleanup_ops(ops); spin_unlock(&net->rules_mod_lock); - synchronize_rcu(); - release_net(net); + call_rcu(&ops->rcu, fib_rules_put_rcu); } EXPORT_SYMBOL_GPL(fib_rules_unregister); diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c index 72495f25269..7466c546f28 100644 --- a/net/decnet/dn_rules.c +++ b/net/decnet/dn_rules.c @@ -33,7 +33,7 @@ #include #include -static struct fib_rules_ops dn_fib_rules_ops; +static struct fib_rules_ops *dn_fib_rules_ops; struct dn_fib_rule { @@ -56,7 +56,7 @@ int dn_fib_lookup(struct flowi *flp, struct dn_fib_res *res) }; int err; - err = fib_rules_lookup(&dn_fib_rules_ops, flp, 0, &arg); + err = fib_rules_lookup(dn_fib_rules_ops, flp, 0, &arg); res->r = arg.rule; return err; @@ -217,9 +217,9 @@ static u32 dn_fib_rule_default_pref(struct fib_rules_ops *ops) struct list_head *pos; struct fib_rule *rule; - if (!list_empty(&dn_fib_rules_ops.rules_list)) { - pos = dn_fib_rules_ops.rules_list.next; - if (pos->next != &dn_fib_rules_ops.rules_list) { + if (!list_empty(&dn_fib_rules_ops->rules_list)) { + pos = dn_fib_rules_ops->rules_list.next; + if (pos->next != &dn_fib_rules_ops->rules_list) { rule = list_entry(pos->next, struct fib_rule, list); if (rule->pref) return rule->pref - 1; @@ -234,7 +234,7 @@ static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops) dn_rt_cache_flush(-1); } -static struct fib_rules_ops dn_fib_rules_ops = { +static struct fib_rules_ops dn_fib_rules_ops_template = { .family = AF_DECnet, .rule_size = sizeof(struct dn_fib_rule), .addr_size = sizeof(u16), @@ -247,21 +247,23 @@ static struct fib_rules_ops dn_fib_rules_ops = { .flush_cache = dn_fib_rule_flush_cache, .nlgroup = RTNLGRP_DECnet_RULE, .policy = dn_fib_rule_policy, - .rules_list = LIST_HEAD_INIT(dn_fib_rules_ops.rules_list), .owner = THIS_MODULE, .fro_net = &init_net, }; void __init dn_fib_rules_init(void) { - BUG_ON(fib_default_rule_add(&dn_fib_rules_ops, 0x7fff, + dn_fib_rules_ops = + fib_rules_register(&dn_fib_rules_ops_template, &init_net); + BUG_ON(IS_ERR(dn_fib_rules_ops)); + BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff, RT_TABLE_MAIN, 0)); - fib_rules_register(&dn_fib_rules_ops); } void __exit dn_fib_rules_cleanup(void) { - fib_rules_unregister(&dn_fib_rules_ops); + fib_rules_unregister(dn_fib_rules_ops); + rcu_barrier(); } diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c index 1239ed23cab..ca2d07b1c70 100644 --- a/net/ipv4/fib_rules.c +++ b/net/ipv4/fib_rules.c @@ -301,13 +301,9 @@ int __net_init fib4_rules_init(struct net *net) int err; struct fib_rules_ops *ops; - ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL); - if (ops == NULL) - return -ENOMEM; - INIT_LIST_HEAD(&ops->rules_list); - ops->fro_net = net; - - fib_rules_register(ops); + ops = fib_rules_register(&fib4_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); err = fib_default_rules_init(ops); if (err < 0) @@ -318,12 +314,10 @@ int __net_init fib4_rules_init(struct net *net) fail: /* also cleans all rules already added */ fib_rules_unregister(ops); - kfree(ops); return err; } void __net_exit fib4_rules_exit(struct net *net) { fib_rules_unregister(net->ipv4.rules_ops); - kfree(net->ipv4.rules_ops); } diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index 3b38f49f2c2..b7aa7c64cc4 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -264,16 +264,14 @@ static struct fib_rules_ops fib6_rules_ops_template = { static int fib6_rules_net_init(struct net *net) { + struct fib_rules_ops *ops; int err = -ENOMEM; - net->ipv6.fib6_rules_ops = kmemdup(&fib6_rules_ops_template, - sizeof(*net->ipv6.fib6_rules_ops), - GFP_KERNEL); - if (!net->ipv6.fib6_rules_ops) - goto out; + ops = fib_rules_register(&fib6_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + net->ipv6.fib6_rules_ops = ops; - net->ipv6.fib6_rules_ops->fro_net = net; - INIT_LIST_HEAD(&net->ipv6.fib6_rules_ops->rules_list); err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0, RT6_TABLE_LOCAL, 0); @@ -283,25 +281,19 @@ static int fib6_rules_net_init(struct net *net) err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0x7FFE, RT6_TABLE_MAIN, 0); if (err) - goto out_fib6_default_rule_add; + goto out_fib6_rules_ops; - err = fib_rules_register(net->ipv6.fib6_rules_ops); - if (err) - goto out_fib6_default_rule_add; out: return err; -out_fib6_default_rule_add: - fib_rules_cleanup_ops(net->ipv6.fib6_rules_ops); out_fib6_rules_ops: - kfree(net->ipv6.fib6_rules_ops); + fib_rules_unregister(ops); goto out; } static void fib6_rules_net_exit(struct net *net) { fib_rules_unregister(net->ipv6.fib6_rules_ops); - kfree(net->ipv6.fib6_rules_ops); } static struct pernet_operations fib6_rules_net_ops = { -- 2.20.1