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Message-ID: <20241021102102.2560279-6-gnaaman@drivenets.com>
Date: Mon, 21 Oct 2024 10:20:57 +0000
From: Gilad Naaman <gnaaman@...venets.com>
To: netdev <netdev@...r.kernel.org>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: Gilad Naaman <gnaaman@...venets.com>,
Kuniyuki Iwashima <kuniyu@...zon.com>
Subject: [PATCH net-next v6 5/6] neighbour: Remove bare neighbour::next pointer
Remove the now-unused neighbour::next pointer, leaving struct neighbour
solely with the hlist_node implementation.
Signed-off-by: Gilad Naaman <gnaaman@...venets.com>
---
include/net/neighbour.h | 4 +-
net/core/neighbour.c | 118 ++++++----------------------------------
net/ipv4/arp.c | 2 +-
3 files changed, 18 insertions(+), 106 deletions(-)
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 68b1970d9045..0244fbd22a1f 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -135,7 +135,6 @@ struct neigh_statistics {
#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)
struct neighbour {
- struct neighbour __rcu *next;
struct hlist_node hash;
struct neigh_table *tbl;
struct neigh_parms *parms;
@@ -191,7 +190,6 @@ struct pneigh_entry {
#define NEIGH_NUM_HASH_RND 4
struct neigh_hash_table {
- struct neighbour __rcu **hash_buckets;
struct hlist_head *hash_heads;
unsigned int hash_shift;
__u32 hash_rnd[NEIGH_NUM_HASH_RND];
@@ -352,7 +350,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb,
int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags,
u32 nlmsg_pid);
void __neigh_set_probe_once(struct neighbour *neigh);
-bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl);
+bool neigh_remove_one(struct neighbour *ndel);
void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);
int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 395078d8b226..47eadf1b2881 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -205,18 +205,12 @@ static void neigh_update_flags(struct neighbour *neigh, u32 flags, int *notify,
}
}
-static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np,
- struct neigh_table *tbl)
+bool neigh_remove_one(struct neighbour *n)
{
bool retval = false;
write_lock(&n->lock);
if (refcount_read(&n->refcnt) == 1) {
- struct neighbour *neigh;
-
- neigh = rcu_dereference_protected(n->next,
- lockdep_is_held(&tbl->lock));
- rcu_assign_pointer(*np, neigh);
hlist_del_rcu(&n->hash);
neigh_mark_dead(n);
retval = true;
@@ -227,29 +221,6 @@ static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np,
return retval;
}
-bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl)
-{
- struct neigh_hash_table *nht;
- void *pkey = ndel->primary_key;
- u32 hash_val;
- struct neighbour *n;
- struct neighbour __rcu **np;
-
- nht = rcu_dereference_protected(tbl->nht,
- lockdep_is_held(&tbl->lock));
- hash_val = tbl->hash(pkey, ndel->dev, nht->hash_rnd);
- hash_val = hash_val >> (32 - nht->hash_shift);
-
- np = &nht->hash_buckets[hash_val];
- while ((n = rcu_dereference_protected(*np,
- lockdep_is_held(&tbl->lock)))) {
- if (n == ndel)
- return neigh_del(n, np, tbl);
- np = &n->next;
- }
- return false;
-}
-
static int neigh_forced_gc(struct neigh_table *tbl)
{
int max_clean = atomic_read(&tbl->gc_entries) -
@@ -277,7 +248,7 @@ static int neigh_forced_gc(struct neigh_table *tbl)
remove = true;
write_unlock(&n->lock);
- if (remove && neigh_remove_one(n, tbl))
+ if (remove && neigh_remove_one(n))
shrunk++;
if (shrunk >= max_clean)
break;
@@ -388,22 +359,15 @@ static void neigh_flush_dev(struct neigh_table *tbl, struct net_device *dev,
lockdep_is_held(&tbl->lock));
for (i = 0; i < (1 << nht->hash_shift); i++) {
- struct neighbour __rcu **np = &nht->hash_buckets[i];
struct hlist_node *tmp;
struct neighbour *n;
neigh_for_each_in_bucket_safe(n, tmp, &nht->hash_heads[i]) {
- if (dev && n->dev != dev) {
- np = &n->next;
+ if (dev && n->dev != dev)
continue;
- }
- if (skip_perm && n->nud_state & NUD_PERMANENT) {
- np = &n->next;
+ if (skip_perm && n->nud_state & NUD_PERMANENT)
continue;
- }
- rcu_assign_pointer(*np,
- rcu_dereference_protected(n->next,
- lockdep_is_held(&tbl->lock)));
+
hlist_del_rcu(&n->hash);
write_lock(&n->lock);
neigh_del_timer(n);
@@ -532,9 +496,7 @@ static void neigh_get_hash_rnd(u32 *x)
static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
{
- size_t hash_heads_size = (1 << shift) * sizeof(struct hlist_head);
- size_t size = (1 << shift) * sizeof(struct neighbour *);
- struct neighbour __rcu **buckets;
+ size_t size = (1 << shift) * sizeof(struct hlist_head);
struct hlist_head *hash_heads;
struct neigh_hash_table *ret;
int i;
@@ -545,33 +507,17 @@ static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
if (!ret)
return NULL;
if (size <= PAGE_SIZE) {
- buckets = kzalloc(size, GFP_ATOMIC);
-
- if (buckets) {
- hash_heads = kzalloc(hash_heads_size, GFP_ATOMIC);
- if (!hash_heads)
- kfree(buckets);
- }
+ hash_heads = kzalloc(size, GFP_ATOMIC);
} else {
- buckets = (struct neighbour __rcu **)
+ hash_heads = (struct hlist_head *)
__get_free_pages(GFP_ATOMIC | __GFP_ZERO,
get_order(size));
- kmemleak_alloc(buckets, size, 1, GFP_ATOMIC);
-
- if (buckets) {
- hash_heads = (struct hlist_head *)
- __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
- get_order(hash_heads_size));
- kmemleak_alloc(hash_heads, hash_heads_size, 1, GFP_ATOMIC);
- if (!hash_heads)
- free_pages((unsigned long)buckets, get_order(size));
- }
+ kmemleak_alloc(hash_heads, size, 1, GFP_ATOMIC);
}
- if (!buckets || !hash_heads) {
+ if (!hash_heads) {
kfree(ret);
return NULL;
}
- ret->hash_buckets = buckets;
ret->hash_heads = hash_heads;
ret->hash_shift = shift;
for (i = 0; i < NEIGH_NUM_HASH_RND; i++)
@@ -584,23 +530,14 @@ static void neigh_hash_free_rcu(struct rcu_head *head)
struct neigh_hash_table *nht = container_of(head,
struct neigh_hash_table,
rcu);
- size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
- struct neighbour __rcu **buckets = nht->hash_buckets;
- size_t hash_heads_size = (1 << nht->hash_shift) * sizeof(struct hlist_head);
+ size_t size = (1 << nht->hash_shift) * sizeof(struct hlist_head);
struct hlist_head *hash_heads = nht->hash_heads;
- if (size <= PAGE_SIZE) {
- kfree(buckets);
- } else {
- kmemleak_free(buckets);
- free_pages((unsigned long)buckets, get_order(size));
- }
-
- if (hash_heads_size < PAGE_SIZE) {
+ if (size < PAGE_SIZE) {
kfree(hash_heads);
} else {
kmemleak_free(hash_heads);
- free_pages((unsigned long)hash_heads, get_order(hash_heads_size));
+ free_pages((unsigned long)hash_heads, get_order(size));
}
kfree(nht);
}
@@ -629,11 +566,6 @@ static struct neigh_hash_table *neigh_hash_grow(struct neigh_table *tbl,
hash >>= (32 - new_nht->hash_shift);
- rcu_assign_pointer(n->next,
- rcu_dereference_protected(
- new_nht->hash_buckets[hash],
- lockdep_is_held(&tbl->lock)));
- rcu_assign_pointer(new_nht->hash_buckets[hash], n);
hlist_del_rcu(&n->hash);
hlist_add_head_rcu(&n->hash, &new_nht->hash_heads[hash]);
}
@@ -738,10 +670,6 @@ ___neigh_create(struct neigh_table *tbl, const void *pkey,
list_add_tail(&n->managed_list, &n->tbl->managed_list);
if (want_ref)
neigh_hold(n);
- rcu_assign_pointer(n->next,
- rcu_dereference_protected(nht->hash_buckets[hash_val],
- lockdep_is_held(&tbl->lock)));
- rcu_assign_pointer(nht->hash_buckets[hash_val], n);
hlist_add_head_rcu(&n->hash, &nht->hash_heads[hash_val]);
write_unlock_bh(&tbl->lock);
neigh_dbg(2, "neigh %p is created\n", n);
@@ -975,7 +903,6 @@ static void neigh_periodic_work(struct work_struct *work)
{
struct neigh_table *tbl = container_of(work, struct neigh_table, gc_work.work);
struct neigh_hash_table *nht;
- struct neighbour __rcu **np;
struct hlist_node *tmp;
struct neighbour *n;
unsigned int i;
@@ -1003,7 +930,6 @@ static void neigh_periodic_work(struct work_struct *work)
goto out;
for (i = 0 ; i < (1 << nht->hash_shift); i++) {
- np = &nht->hash_buckets[i];
neigh_for_each_in_bucket_safe(n, tmp, &nht->hash_heads[i]) {
unsigned int state;
@@ -1014,7 +940,7 @@ static void neigh_periodic_work(struct work_struct *work)
if ((state & (NUD_PERMANENT | NUD_IN_TIMER)) ||
(n->flags & NTF_EXT_LEARNED)) {
write_unlock(&n->lock);
- goto next_elt;
+ continue;
}
if (time_before(n->used, n->confirmed) &&
@@ -1025,9 +951,6 @@ static void neigh_periodic_work(struct work_struct *work)
(state == NUD_FAILED ||
!time_in_range_open(jiffies, n->used,
n->used + NEIGH_VAR(n->parms, GC_STALETIME)))) {
- rcu_assign_pointer(*np,
- rcu_dereference_protected(n->next,
- lockdep_is_held(&tbl->lock)));
hlist_del_rcu(&n->hash);
neigh_mark_dead(n);
write_unlock(&n->lock);
@@ -1035,9 +958,6 @@ static void neigh_periodic_work(struct work_struct *work)
continue;
}
write_unlock(&n->lock);
-
-next_elt:
- np = &n->next;
}
/*
* It's fine to release lock here, even if hash table
@@ -1984,7 +1904,7 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,
NETLINK_CB(skb).portid, extack);
write_lock_bh(&tbl->lock);
neigh_release(neigh);
- neigh_remove_one(neigh, tbl);
+ neigh_remove_one(neigh);
write_unlock_bh(&tbl->lock);
out:
@@ -3143,22 +3063,16 @@ void __neigh_for_each_release(struct neigh_table *tbl,
for (chain = 0; chain < (1 << nht->hash_shift); chain++) {
struct neighbour *n;
struct hlist_node *tmp;
- struct neighbour __rcu **np;
- np = &nht->hash_buckets[chain];
neigh_for_each_in_bucket_safe(n, tmp, &nht->hash_heads[chain]) {
int release;
write_lock(&n->lock);
release = cb(n);
if (release) {
- rcu_assign_pointer(*np,
- rcu_dereference_protected(n->next,
- lockdep_is_held(&tbl->lock)));
hlist_del_rcu(&n->hash);
neigh_mark_dead(n);
- } else
- np = &n->next;
+ }
write_unlock(&n->lock);
if (release)
neigh_cleanup_and_release(n);
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 11c1519b3699..cb9a7ed8abd3 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1215,7 +1215,7 @@ int arp_invalidate(struct net_device *dev, __be32 ip, bool force)
NEIGH_UPDATE_F_ADMIN, 0);
write_lock_bh(&tbl->lock);
neigh_release(neigh);
- neigh_remove_one(neigh, tbl);
+ neigh_remove_one(neigh);
write_unlock_bh(&tbl->lock);
}
--
2.46.0
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