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netfilter: use kvmalloc_array to allocate memory for hashtable

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nf_ct_alloc_hashtable is used to allocate memory for conntrack,
NAT bysrc and expectation hashtable. Assuming 64k bucket size,
which means 7th order page allocation, __get_free_pages, called
by nf_ct_alloc_hashtable, will trigger the direct memory reclaim
and stall for a long time, when system has lots of memory stress

so replace combination of __get_free_pages and vzalloc with
kvmalloc_array, which provides a overflow check and a fallback
if no high order memory is available, and do not retry to reclaim
memory, reduce stall

and remove nf_ct_free_hashtable, since it is just a kvfree

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Wang Li <wangli39@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Li RongQing 2018-07-25 15:52:13 +08:00 committed by Pablo Neira Ayuso
parent 4ed8eb6570
commit 285189c78e
5 changed files with 11 additions and 30 deletions
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2
include/net/netfilter/nf_conntrack.h
View File

@ -176,8 +176,6 @@ void nf_ct_netns_put(struct net *net, u8 nfproto);
*/
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
void nf_ct_free_hashtable(void *hash, unsigned int size);
int nf_conntrack_hash_check_insert(struct nf_conn *ct);
bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);

29
net/netfilter/nf_conntrack_core.c
View File

@ -2022,16 +2022,6 @@ static int kill_all(struct nf_conn *i, void *data)
return net_eq(nf_ct_net(i), data);
}
void nf_ct_free_hashtable(void *hash, unsigned int size)
{
if (is_vmalloc_addr(hash))
vfree(hash);
else
free_pages((unsigned long)hash,
get_order(sizeof(struct hlist_head) * size));
}
EXPORT_SYMBOL_GPL(nf_ct_free_hashtable);
void nf_conntrack_cleanup_start(void)
{
conntrack_gc_work.exiting = true;
@ -2042,7 +2032,7 @@ void nf_conntrack_cleanup_end(void)
{
RCU_INIT_POINTER(nf_ct_hook, NULL);
cancel_delayed_work_sync(&conntrack_gc_work.dwork);
nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
kvfree(nf_conntrack_hash);
nf_conntrack_proto_fini();
nf_conntrack_seqadj_fini();
@ -2108,7 +2098,6 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
{
struct hlist_nulls_head *hash;
unsigned int nr_slots, i;
size_t sz;
if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
return NULL;
@ -2116,14 +2105,8 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
if (nr_slots > (UINT_MAX / sizeof(struct hlist_nulls_head)))
return NULL;
sz = nr_slots * sizeof(struct hlist_nulls_head);
hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
get_order(sz));
if (!hash)
hash = vzalloc(sz);
hash = kvmalloc_array(nr_slots, sizeof(struct hlist_nulls_head),
GFP_KERNEL | __GFP_ZERO);
if (hash && nulls)
for (i = 0; i < nr_slots; i++)
@ -2150,7 +2133,7 @@ int nf_conntrack_hash_resize(unsigned int hashsize)
old_size = nf_conntrack_htable_size;
if (old_size == hashsize) {
nf_ct_free_hashtable(hash, hashsize);
kvfree(hash);
return 0;
}
@ -2186,7 +2169,7 @@ int nf_conntrack_hash_resize(unsigned int hashsize)
local_bh_enable();
synchronize_net();
nf_ct_free_hashtable(old_hash, old_size);
kvfree(old_hash);
return 0;
}
@ -2350,7 +2333,7 @@ err_acct:
err_expect:
kmem_cache_destroy(nf_conntrack_cachep);
err_cachep:
nf_ct_free_hashtable(nf_conntrack_hash, nf_conntrack_htable_size);
kvfree(nf_conntrack_hash);
return ret;
}

2
net/netfilter/nf_conntrack_expect.c
View File

@ -712,5 +712,5 @@ void nf_conntrack_expect_fini(void)
{
rcu_barrier(); /* Wait for call_rcu() before destroy */
kmem_cache_destroy(nf_ct_expect_cachep);
nf_ct_free_hashtable(nf_ct_expect_hash, nf_ct_expect_hsize);
kvfree(nf_ct_expect_hash);
}

4
net/netfilter/nf_conntrack_helper.c
View File

@ -562,12 +562,12 @@ int nf_conntrack_helper_init(void)
return 0;
out_extend:
nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize);
kvfree(nf_ct_helper_hash);
return ret;
}
void nf_conntrack_helper_fini(void)
{
nf_ct_extend_unregister(&helper_extend);
nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_hsize);
kvfree(nf_ct_helper_hash);
}

4
net/netfilter/nf_nat_core.c
View File

@ -1056,7 +1056,7 @@ static int __init nf_nat_init(void)
ret = nf_ct_extend_register(&nat_extend);
if (ret < 0) {
nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
kvfree(nf_nat_bysource);
pr_err("Unable to register extension\n");
return ret;
}
@ -1094,7 +1094,7 @@ static void __exit nf_nat_cleanup(void)
for (i = 0; i < NFPROTO_NUMPROTO; i++)
kfree(nf_nat_l4protos[i]);
synchronize_net();
nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
kvfree(nf_nat_bysource);
unregister_pernet_subsys(&nat_net_ops);
}