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ipv6: flowlabel: do not disable BH where not needed 

struct ip6_flowlabel are rcu managed, and call_rcu() is used
to delay fl_free_rcu() after RCU grace period.

There is no point disabling BH for pure RCU lookups.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet 2023-03-21 04:01:13 +00:00 committed by Jakub Kicinski
parent f6f4e739b1
commit 4c5c496a94
1 changed files with 27 additions and 24 deletions
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51
net/ipv6/ip6_flowlabel.c
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@ -58,18 +58,18 @@ DEFINE_STATIC_KEY_DEFERRED_FALSE(ipv6_flowlabel_exclusive, HZ);
EXPORT_SYMBOL(ipv6_flowlabel_exclusive);
#define for_each_fl_rcu(hash, fl) \
for (fl = rcu_dereference_bh(fl_ht[(hash)]); \
for (fl = rcu_dereference(fl_ht[(hash)]); \
fl != NULL; \
fl = rcu_dereference_bh(fl->next))
fl = rcu_dereference(fl->next))
#define for_each_fl_continue_rcu(fl) \
for (fl = rcu_dereference_bh(fl->next); \
for (fl = rcu_dereference(fl->next); \
fl != NULL; \
fl = rcu_dereference_bh(fl->next))
fl = rcu_dereference(fl->next))
#define for_each_sk_fl_rcu(np, sfl) \
for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \
for (sfl = rcu_dereference(np->ipv6_fl_list); \
sfl != NULL; \
sfl = rcu_dereference_bh(sfl->next))
sfl = rcu_dereference(sfl->next))
static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
{
@ -86,11 +86,11 @@ static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
{
struct ip6_flowlabel *fl;
rcu_read_lock_bh();
rcu_read_lock();
fl = __fl_lookup(net, label);
if (fl && !atomic_inc_not_zero(&fl->users))
fl = NULL;
rcu_read_unlock_bh();
rcu_read_unlock();
return fl;
}
@ -217,6 +217,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
fl->label = label & IPV6_FLOWLABEL_MASK;
rcu_read_lock();
spin_lock_bh(&ip6_fl_lock);
if (label == 0) {
for (;;) {
@ -240,6 +241,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
if (lfl) {
atomic_inc(&lfl->users);
spin_unlock_bh(&ip6_fl_lock);
rcu_read_unlock();
return lfl;
}
}
@ -249,6 +251,7 @@ static struct ip6_flowlabel *fl_intern(struct net *net,
rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
atomic_inc(&fl_size);
spin_unlock_bh(&ip6_fl_lock);
rcu_read_unlock();
return NULL;
}
@ -263,17 +266,17 @@ struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
label &= IPV6_FLOWLABEL_MASK;
rcu_read_lock_bh();
rcu_read_lock();
for_each_sk_fl_rcu(np, sfl) {
struct ip6_flowlabel *fl = sfl->fl;
if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
fl->lastuse = jiffies;
rcu_read_unlock_bh();
rcu_read_unlock();
return fl;
}
}
rcu_read_unlock_bh();
rcu_read_unlock();
return NULL;
}
EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
@ -475,10 +478,10 @@ static int mem_check(struct sock *sk)
if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
return 0;
rcu_read_lock_bh();
rcu_read_lock();
for_each_sk_fl_rcu(np, sfl)
count++;
rcu_read_unlock_bh();
rcu_read_unlock();
if (room <= 0 ||
((count >= FL_MAX_PER_SOCK ||
@ -515,7 +518,7 @@ int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
return 0;
}
rcu_read_lock_bh();
rcu_read_lock();
for_each_sk_fl_rcu(np, sfl) {
if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
@ -527,11 +530,11 @@ int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
freq->flr_linger = sfl->fl->linger / HZ;
spin_unlock_bh(&ip6_fl_lock);
rcu_read_unlock_bh();
rcu_read_unlock();
return 0;
}
}
rcu_read_unlock_bh();
rcu_read_unlock();
return -ENOENT;
}
@ -581,16 +584,16 @@ static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
struct ipv6_fl_socklist *sfl;
int err;
rcu_read_lock_bh();
rcu_read_lock();
for_each_sk_fl_rcu(np, sfl) {
if (sfl->fl->label == freq->flr_label) {
err = fl6_renew(sfl->fl, freq->flr_linger,
freq->flr_expires);
rcu_read_unlock_bh();
rcu_read_unlock();
return err;
}
}
rcu_read_unlock_bh();
rcu_read_unlock();
if (freq->flr_share == IPV6_FL_S_NONE &&
ns_capable(net->user_ns, CAP_NET_ADMIN)) {
@ -641,11 +644,11 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
if (freq->flr_label) {
err = -EEXIST;
rcu_read_lock_bh();
rcu_read_lock();
for_each_sk_fl_rcu(np, sfl) {
if (sfl->fl->label == freq->flr_label) {
if (freq->flr_flags & IPV6_FL_F_EXCL) {
rcu_read_unlock_bh();
rcu_read_unlock();
goto done;
}
fl1 = sfl->fl;
@ -654,7 +657,7 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
break;
}
}
rcu_read_unlock_bh();
rcu_read_unlock();
if (!fl1)
fl1 = fl_lookup(net, freq->flr_label);
@ -809,7 +812,7 @@ static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
rcu_read_lock_bh();
rcu_read_lock();
return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
@ -828,7 +831,7 @@ static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
static void ip6fl_seq_stop(struct seq_file *seq, void *v)
__releases(RCU)
{
rcu_read_unlock_bh();
rcu_read_unlock();
}
static int ip6fl_seq_show(struct seq_file *seq, void *v)