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net: Allow fib_rule_unregister to batch
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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 <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric W. Biederman authored and David S. Miller committed Dec 3, 2009
1 parent 3a765ed commit e9c5158
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Showing 5 changed files with 57 additions and 38 deletions.
3 changes: 2 additions & 1 deletion include/net/fib_rules.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 \
Expand Down Expand Up @@ -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 *);

Expand Down
36 changes: 33 additions & 3 deletions net/core/fib_rules.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -102,6 +102,28 @@ int fib_rules_register(struct fib_rules_ops *ops)
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)
Expand All @@ -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;
Expand All @@ -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);
Expand Down
22 changes: 12 additions & 10 deletions net/decnet/dn_rules.c
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Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@
#include <net/dn_dev.h>
#include <net/dn_route.h>

static struct fib_rules_ops dn_fib_rules_ops;
static struct fib_rules_ops *dn_fib_rules_ops;

struct dn_fib_rule
{
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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),
Expand All @@ -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();
}


12 changes: 3 additions & 9 deletions net/ipv4/fib_rules.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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);
}
22 changes: 7 additions & 15 deletions net/ipv6/fib6_rules.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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 = {
Expand Down

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