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[NETFILTER]: nf_conntrack: switch protocol registration/unregistration to mutex 

The protocol lookups done by nf_conntrack are already protected by RCU,
there is no need to keep taking nf_conntrack_lock for registration
and unregistration. Switch to a mutex.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-03-14 16:37:52 -07:00 committed by David S. Miller
parent 587aa64163
commit b19caa0ca0
1 changed files with 23 additions and 29 deletions
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52
net/netfilter/nf_conntrack_proto.c
View File

@ -32,9 +32,9 @@ struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly; struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
EXPORT_SYMBOL_GPL(nf_ct_l3protos); EXPORT_SYMBOL_GPL(nf_ct_l3protos);
#ifdef CONFIG_SYSCTL static DEFINE_MUTEX(nf_ct_proto_mutex);
static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);
#ifdef CONFIG_SYSCTL
static int static int
nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path, nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path,
struct ctl_table *table, unsigned int *users) struct ctl_table *table, unsigned int *users)
@ -164,13 +164,13 @@ static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
int err = 0; int err = 0;
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
mutex_lock(&nf_ct_proto_sysctl_mutex); mutex_lock(&nf_ct_proto_mutex);
if (l3proto->ctl_table != NULL) { if (l3proto->ctl_table != NULL) {
err = nf_ct_register_sysctl(&l3proto->ctl_table_header, err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
l3proto->ctl_table_path, l3proto->ctl_table_path,
l3proto->ctl_table, NULL); l3proto->ctl_table, NULL);
} }
mutex_unlock(&nf_ct_proto_sysctl_mutex); mutex_unlock(&nf_ct_proto_mutex);
#endif #endif
return err; return err;
} }
@ -178,11 +178,11 @@ static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto) static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
{ {
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
mutex_lock(&nf_ct_proto_sysctl_mutex); mutex_lock(&nf_ct_proto_mutex);
if (l3proto->ctl_table_header != NULL) if (l3proto->ctl_table_header != NULL)
nf_ct_unregister_sysctl(&l3proto->ctl_table_header, nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
l3proto->ctl_table, NULL); l3proto->ctl_table, NULL);
mutex_unlock(&nf_ct_proto_sysctl_mutex); mutex_unlock(&nf_ct_proto_mutex);
#endif #endif
} }
@ -195,13 +195,13 @@ int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
goto out; goto out;
} }
write_lock_bh(&nf_conntrack_lock); mutex_lock(&nf_ct_proto_mutex);
if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
ret = -EBUSY; ret = -EBUSY;
goto out_unlock; goto out_unlock;
} }
rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto); rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
ret = nf_ct_l3proto_register_sysctl(proto); ret = nf_ct_l3proto_register_sysctl(proto);
if (ret < 0) if (ret < 0)
@ -209,7 +209,7 @@ int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
return ret; return ret;
out_unlock: out_unlock:
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
out: out:
return ret; return ret;
} }
@ -219,11 +219,11 @@ void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{ {
BUG_ON(proto->l3proto >= AF_MAX); BUG_ON(proto->l3proto >= AF_MAX);
write_lock_bh(&nf_conntrack_lock); mutex_lock(&nf_ct_proto_mutex);
BUG_ON(nf_ct_l3protos[proto->l3proto] != proto); BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
&nf_conntrack_l3proto_generic); &nf_conntrack_l3proto_generic);
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
synchronize_rcu(); synchronize_rcu();
nf_ct_l3proto_unregister_sysctl(proto); nf_ct_l3proto_unregister_sysctl(proto);
@ -238,7 +238,7 @@ static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
int err = 0; int err = 0;
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
mutex_lock(&nf_ct_proto_sysctl_mutex); mutex_lock(&nf_ct_proto_mutex);
if (l4proto->ctl_table != NULL) { if (l4proto->ctl_table != NULL) {
err = nf_ct_register_sysctl(l4proto->ctl_table_header, err = nf_ct_register_sysctl(l4proto->ctl_table_header,
nf_net_netfilter_sysctl_path, nf_net_netfilter_sysctl_path,
@ -260,7 +260,7 @@ static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
} }
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
out: out:
mutex_unlock(&nf_ct_proto_sysctl_mutex); mutex_unlock(&nf_ct_proto_mutex);
#endif /* CONFIG_SYSCTL */ #endif /* CONFIG_SYSCTL */
return err; return err;
} }
@ -268,7 +268,7 @@ out:
static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto) static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
{ {
#ifdef CONFIG_SYSCTL #ifdef CONFIG_SYSCTL
mutex_lock(&nf_ct_proto_sysctl_mutex); mutex_lock(&nf_ct_proto_mutex);
if (l4proto->ctl_table_header != NULL && if (l4proto->ctl_table_header != NULL &&
*l4proto->ctl_table_header != NULL) *l4proto->ctl_table_header != NULL)
nf_ct_unregister_sysctl(l4proto->ctl_table_header, nf_ct_unregister_sysctl(l4proto->ctl_table_header,
@ -279,7 +279,7 @@ static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto
nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header, nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
l4proto->ctl_compat_table, NULL); l4proto->ctl_compat_table, NULL);
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
mutex_unlock(&nf_ct_proto_sysctl_mutex); mutex_unlock(&nf_ct_proto_mutex);
#endif /* CONFIG_SYSCTL */ #endif /* CONFIG_SYSCTL */
} }
@ -297,8 +297,8 @@ int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
if (l4proto == &nf_conntrack_l4proto_generic) if (l4proto == &nf_conntrack_l4proto_generic)
return nf_ct_l4proto_register_sysctl(l4proto); return nf_ct_l4proto_register_sysctl(l4proto);
mutex_lock(&nf_ct_proto_mutex);
retry: retry:
write_lock_bh(&nf_conntrack_lock);
if (nf_ct_protos[l4proto->l3proto]) { if (nf_ct_protos[l4proto->l3proto]) {
if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
!= &nf_conntrack_l4proto_generic) { != &nf_conntrack_l4proto_generic) {
@ -310,28 +310,22 @@ retry:
struct nf_conntrack_l4proto **proto_array; struct nf_conntrack_l4proto **proto_array;
int i; int i;
write_unlock_bh(&nf_conntrack_lock);
proto_array = (struct nf_conntrack_l4proto **) proto_array = (struct nf_conntrack_l4proto **)
kmalloc(MAX_NF_CT_PROTO * kmalloc(MAX_NF_CT_PROTO *
sizeof(struct nf_conntrack_l4proto *), sizeof(struct nf_conntrack_l4proto *),
GFP_KERNEL); GFP_KERNEL);
if (proto_array == NULL) { if (proto_array == NULL) {
ret = -ENOMEM; ret = -ENOMEM;
goto out; goto out_unlock;
} }
for (i = 0; i < MAX_NF_CT_PROTO; i++) for (i = 0; i < MAX_NF_CT_PROTO; i++)
proto_array[i] = &nf_conntrack_l4proto_generic; proto_array[i] = &nf_conntrack_l4proto_generic;
write_lock_bh(&nf_conntrack_lock); if (nf_ct_protos[l4proto->l3proto])
if (nf_ct_protos[l4proto->l3proto]) {
/* bad timing, but no problem */ /* bad timing, but no problem */
write_unlock_bh(&nf_conntrack_lock);
kfree(proto_array); kfree(proto_array);
} else { else
nf_ct_protos[l4proto->l3proto] = proto_array; nf_ct_protos[l4proto->l3proto] = proto_array;
write_unlock_bh(&nf_conntrack_lock);
}
/* /*
* Just once because array is never freed until unloading * Just once because array is never freed until unloading
@ -341,7 +335,7 @@ retry:
} }
rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto); rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto);
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
ret = nf_ct_l4proto_register_sysctl(l4proto); ret = nf_ct_l4proto_register_sysctl(l4proto);
if (ret < 0) if (ret < 0)
@ -349,7 +343,7 @@ retry:
return ret; return ret;
out_unlock: out_unlock:
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
out: out:
return ret; return ret;
} }
@ -364,11 +358,11 @@ void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
return; return;
} }
write_lock_bh(&nf_conntrack_lock); mutex_lock(&nf_ct_proto_mutex);
BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto); BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
&nf_conntrack_l4proto_generic); &nf_conntrack_l4proto_generic);
write_unlock_bh(&nf_conntrack_lock); mutex_unlock(&nf_ct_proto_mutex);
synchronize_rcu(); synchronize_rcu();
nf_ct_l4proto_unregister_sysctl(l4proto); nf_ct_l4proto_unregister_sysctl(l4proto);