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netfilter: nfnetlink_log: remove rcu_bh usage

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structure is free'd via call_rcu, so its safe to use rcu_read_lock only.

While at it, skip rcu_read_lock for lookup from packet path, its always
called with rcu held.

Signed-off-by: Florian Westphal <fw@strlen.de>
This commit is contained in:
Florian Westphal 2023-03-28 18:44:15 +02:00
parent da617cd8d9
commit 356e2adb3f
1 changed files with 23 additions and 13 deletions
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36
net/netfilter/nfnetlink_log.c
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@ -103,9 +103,9 @@ static inline u_int8_t instance_hashfn(u_int16_t group_num)
}
static struct nfulnl_instance *
__instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)
__instance_lookup(const struct nfnl_log_net *log, u16 group_num)
{
struct hlist_head *head;
const struct hlist_head *head;
struct nfulnl_instance *inst;
head = &log->instance_table[instance_hashfn(group_num)];
@ -123,15 +123,25 @@ instance_get(struct nfulnl_instance *inst)
}
static struct nfulnl_instance *
instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)
instance_lookup_get_rcu(const struct nfnl_log_net *log, u16 group_num)
{
struct nfulnl_instance *inst;
rcu_read_lock_bh();
inst = __instance_lookup(log, group_num);
if (inst && !refcount_inc_not_zero(&inst->use))
inst = NULL;
rcu_read_unlock_bh();
return inst;
}
static struct nfulnl_instance *
instance_lookup_get(const struct nfnl_log_net *log, u16 group_num)
{
struct nfulnl_instance *inst;
rcu_read_lock();
inst = instance_lookup_get_rcu(log, group_num);
rcu_read_unlock();
return inst;
}
@ -698,7 +708,7 @@ nfulnl_log_packet(struct net *net,
else
li = &default_loginfo;
inst = instance_lookup_get(log, li->u.ulog.group);
inst = instance_lookup_get_rcu(log, li->u.ulog.group);
if (!inst)
return;
@ -1030,7 +1040,7 @@ static struct hlist_node *get_first(struct net *net, struct iter_state *st)
struct hlist_head *head = &log->instance_table[st->bucket];
if (!hlist_empty(head))
return rcu_dereference_bh(hlist_first_rcu(head));
return rcu_dereference(hlist_first_rcu(head));
}
return NULL;
}
@ -1038,7 +1048,7 @@ static struct hlist_node *get_first(struct net *net, struct iter_state *st)
static struct hlist_node *get_next(struct net *net, struct iter_state *st,
struct hlist_node *h)
{
h = rcu_dereference_bh(hlist_next_rcu(h));
h = rcu_dereference(hlist_next_rcu(h));
while (!h) {
struct nfnl_log_net *log;
struct hlist_head *head;
@ -1048,7 +1058,7 @@ static struct hlist_node *get_next(struct net *net, struct iter_state *st,
log = nfnl_log_pernet(net);
head = &log->instance_table[st->bucket];
h = rcu_dereference_bh(hlist_first_rcu(head));
h = rcu_dereference(hlist_first_rcu(head));
}
return h;
}
@ -1066,9 +1076,9 @@ static struct hlist_node *get_idx(struct net *net, struct iter_state *st,
}
static void *seq_start(struct seq_file *s, loff_t *pos)
__acquires(rcu_bh)
__acquires(rcu)
{
rcu_read_lock_bh();
rcu_read_lock();
return get_idx(seq_file_net(s), s->private, *pos);
}
@ -1079,9 +1089,9 @@ static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
}
static void seq_stop(struct seq_file *s, void *v)
__releases(rcu_bh)
__releases(rcu)
{
rcu_read_unlock_bh();
rcu_read_unlock();
}
static int seq_show(struct seq_file *s, void *v)