Commit 2ed3bf18 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso

netfilter: ecache: use dedicated list for event redelivery

This disentangles event redelivery and the percpu dying list.

Because entries are now stored on a dedicated list, all
entries are in NFCT_ECACHE_DESTROY_FAIL state and all entries
still have confirmed bit set -- the reference count is at least 1.

The 'struct net' back-pointer can be removed as well.

The pcpu dying list will be removed eventually, it has no functionality.
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent a997157e
...@@ -45,7 +45,8 @@ union nf_conntrack_expect_proto { ...@@ -45,7 +45,8 @@ union nf_conntrack_expect_proto {
struct nf_conntrack_net_ecache { struct nf_conntrack_net_ecache {
struct delayed_work dwork; struct delayed_work dwork;
struct netns_ct *ct_net; spinlock_t dying_lock;
struct hlist_nulls_head dying_list;
}; };
struct nf_conntrack_net { struct nf_conntrack_net {
......
...@@ -14,7 +14,6 @@ ...@@ -14,7 +14,6 @@
#include <net/netfilter/nf_conntrack_extend.h> #include <net/netfilter/nf_conntrack_extend.h>
enum nf_ct_ecache_state { enum nf_ct_ecache_state {
NFCT_ECACHE_UNKNOWN, /* destroy event not sent */
NFCT_ECACHE_DESTROY_FAIL, /* tried but failed to send destroy event */ NFCT_ECACHE_DESTROY_FAIL, /* tried but failed to send destroy event */
NFCT_ECACHE_DESTROY_SENT, /* sent destroy event after failure */ NFCT_ECACHE_DESTROY_SENT, /* sent destroy event after failure */
}; };
...@@ -23,7 +22,6 @@ struct nf_conntrack_ecache { ...@@ -23,7 +22,6 @@ struct nf_conntrack_ecache {
unsigned long cache; /* bitops want long */ unsigned long cache; /* bitops want long */
u16 ctmask; /* bitmask of ct events to be delivered */ u16 ctmask; /* bitmask of ct events to be delivered */
u16 expmask; /* bitmask of expect events to be delivered */ u16 expmask; /* bitmask of expect events to be delivered */
enum nf_ct_ecache_state state:8;/* ecache state */
u32 missed; /* missed events */ u32 missed; /* missed events */
u32 portid; /* netlink portid of destroyer */ u32 portid; /* netlink portid of destroyer */
}; };
......
...@@ -660,15 +660,12 @@ void nf_ct_destroy(struct nf_conntrack *nfct) ...@@ -660,15 +660,12 @@ void nf_ct_destroy(struct nf_conntrack *nfct)
} }
EXPORT_SYMBOL(nf_ct_destroy); EXPORT_SYMBOL(nf_ct_destroy);
static void nf_ct_delete_from_lists(struct nf_conn *ct) static void __nf_ct_delete_from_lists(struct nf_conn *ct)
{ {
struct net *net = nf_ct_net(ct); struct net *net = nf_ct_net(ct);
unsigned int hash, reply_hash; unsigned int hash, reply_hash;
unsigned int sequence; unsigned int sequence;
nf_ct_helper_destroy(ct);
local_bh_disable();
do { do {
sequence = read_seqcount_begin(&nf_conntrack_generation); sequence = read_seqcount_begin(&nf_conntrack_generation);
hash = hash_conntrack(net, hash = hash_conntrack(net,
...@@ -681,12 +678,33 @@ static void nf_ct_delete_from_lists(struct nf_conn *ct) ...@@ -681,12 +678,33 @@ static void nf_ct_delete_from_lists(struct nf_conn *ct)
clean_from_lists(ct); clean_from_lists(ct);
nf_conntrack_double_unlock(hash, reply_hash); nf_conntrack_double_unlock(hash, reply_hash);
}
static void nf_ct_delete_from_lists(struct nf_conn *ct)
{
nf_ct_helper_destroy(ct);
local_bh_disable();
__nf_ct_delete_from_lists(ct);
nf_ct_add_to_dying_list(ct); nf_ct_add_to_dying_list(ct);
local_bh_enable(); local_bh_enable();
} }
static void nf_ct_add_to_ecache_list(struct nf_conn *ct)
{
#ifdef CONFIG_NF_CONNTRACK_EVENTS
struct nf_conntrack_net *cnet = nf_ct_pernet(nf_ct_net(ct));
spin_lock(&cnet->ecache.dying_lock);
hlist_nulls_add_head_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode,
&cnet->ecache.dying_list);
spin_unlock(&cnet->ecache.dying_lock);
#else
nf_ct_add_to_dying_list(ct);
#endif
}
bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report) bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
{ {
struct nf_conn_tstamp *tstamp; struct nf_conn_tstamp *tstamp;
...@@ -709,7 +727,12 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report) ...@@ -709,7 +727,12 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
/* destroy event was not delivered. nf_ct_put will /* destroy event was not delivered. nf_ct_put will
* be done by event cache worker on redelivery. * be done by event cache worker on redelivery.
*/ */
nf_ct_delete_from_lists(ct); nf_ct_helper_destroy(ct);
local_bh_disable();
__nf_ct_delete_from_lists(ct);
nf_ct_add_to_ecache_list(ct);
local_bh_enable();
nf_conntrack_ecache_work(nf_ct_net(ct), NFCT_ECACHE_DESTROY_FAIL); nf_conntrack_ecache_work(nf_ct_net(ct), NFCT_ECACHE_DESTROY_FAIL);
return false; return false;
} }
......
...@@ -16,7 +16,6 @@ ...@@ -16,7 +16,6 @@
#include <linux/vmalloc.h> #include <linux/vmalloc.h>
#include <linux/stddef.h> #include <linux/stddef.h>
#include <linux/err.h> #include <linux/err.h>
#include <linux/percpu.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/netdevice.h> #include <linux/netdevice.h>
#include <linux/slab.h> #include <linux/slab.h>
...@@ -29,8 +28,9 @@ ...@@ -29,8 +28,9 @@
static DEFINE_MUTEX(nf_ct_ecache_mutex); static DEFINE_MUTEX(nf_ct_ecache_mutex);
#define ECACHE_RETRY_WAIT (HZ/10) #define DYING_NULLS_VAL ((1 << 30) + 1)
#define ECACHE_STACK_ALLOC (256 / sizeof(void *)) #define ECACHE_MAX_JIFFIES msecs_to_jiffies(10)
#define ECACHE_RETRY_JIFFIES msecs_to_jiffies(10)
enum retry_state { enum retry_state {
STATE_CONGESTED, STATE_CONGESTED,
...@@ -38,58 +38,58 @@ enum retry_state { ...@@ -38,58 +38,58 @@ enum retry_state {
STATE_DONE, STATE_DONE,
}; };
static enum retry_state ecache_work_evict_list(struct ct_pcpu *pcpu) static enum retry_state ecache_work_evict_list(struct nf_conntrack_net *cnet)
{ {
struct nf_conn *refs[ECACHE_STACK_ALLOC]; unsigned long stop = jiffies + ECACHE_MAX_JIFFIES;
struct hlist_nulls_head evicted_list;
enum retry_state ret = STATE_DONE; enum retry_state ret = STATE_DONE;
struct nf_conntrack_tuple_hash *h; struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n; struct hlist_nulls_node *n;
unsigned int evicted = 0; unsigned int sent;
spin_lock(&pcpu->lock); INIT_HLIST_NULLS_HEAD(&evicted_list, DYING_NULLS_VAL);
hlist_nulls_for_each_entry(h, n, &pcpu->dying, hnnode) { next:
sent = 0;
spin_lock_bh(&cnet->ecache.dying_lock);
hlist_nulls_for_each_entry_safe(h, n, &cnet->ecache.dying_list, hnnode) {
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
struct nf_conntrack_ecache *e;
if (!nf_ct_is_confirmed(ct))
continue;
/* This ecache access is safe because the ct is on the
* pcpu dying list and we hold the spinlock -- the entry
* cannot be free'd until after the lock is released.
*
* This is true even if ct has a refcount of 0: the
* cpu that is about to free the entry must remove it
* from the dying list and needs the lock to do so.
*/
e = nf_ct_ecache_find(ct);
if (!e || e->state != NFCT_ECACHE_DESTROY_FAIL)
continue;
/* ct is in NFCT_ECACHE_DESTROY_FAIL state, this means /* The worker owns all entries, ct remains valid until nf_ct_put
* the worker owns this entry: the ct will remain valid * in the loop below.
* until the worker puts its ct reference.
*/ */
if (nf_conntrack_event(IPCT_DESTROY, ct)) { if (nf_conntrack_event(IPCT_DESTROY, ct)) {
ret = STATE_CONGESTED; ret = STATE_CONGESTED;
break; break;
} }
e->state = NFCT_ECACHE_DESTROY_SENT; hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
refs[evicted] = ct; hlist_nulls_add_head(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode, &evicted_list);
if (++evicted >= ARRAY_SIZE(refs)) { if (time_after(stop, jiffies)) {
ret = STATE_RESTART; ret = STATE_RESTART;
break; break;
} }
if (sent++ > 16) {
spin_unlock_bh(&cnet->ecache.dying_lock);
cond_resched();
goto next;
}
} }
spin_unlock(&pcpu->lock); spin_unlock_bh(&cnet->ecache.dying_lock);
/* can't _put while holding lock */ hlist_nulls_for_each_entry_safe(h, n, &evicted_list, hnnode) {
while (evicted) struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
nf_ct_put(refs[--evicted]);
hlist_nulls_add_fake(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode);
nf_ct_put(ct);
cond_resched();
}
return ret; return ret;
} }
...@@ -97,35 +97,20 @@ static enum retry_state ecache_work_evict_list(struct ct_pcpu *pcpu) ...@@ -97,35 +97,20 @@ static enum retry_state ecache_work_evict_list(struct ct_pcpu *pcpu)
static void ecache_work(struct work_struct *work) static void ecache_work(struct work_struct *work)
{ {
struct nf_conntrack_net *cnet = container_of(work, struct nf_conntrack_net, ecache.dwork.work); struct nf_conntrack_net *cnet = container_of(work, struct nf_conntrack_net, ecache.dwork.work);
struct netns_ct *ctnet = cnet->ecache.ct_net; int ret, delay = -1;
int cpu, delay = -1;
struct ct_pcpu *pcpu; ret = ecache_work_evict_list(cnet);
switch (ret) {
local_bh_disable(); case STATE_CONGESTED:
delay = ECACHE_RETRY_JIFFIES;
for_each_possible_cpu(cpu) { break;
enum retry_state ret; case STATE_RESTART:
delay = 0;
pcpu = per_cpu_ptr(ctnet->pcpu_lists, cpu); break;
case STATE_DONE:
ret = ecache_work_evict_list(pcpu); break;
switch (ret) {
case STATE_CONGESTED:
delay = ECACHE_RETRY_WAIT;
goto out;
case STATE_RESTART:
delay = 0;
break;
case STATE_DONE:
break;
}
} }
out:
local_bh_enable();
ctnet->ecache_dwork_pending = delay > 0;
if (delay >= 0) if (delay >= 0)
schedule_delayed_work(&cnet->ecache.dwork, delay); schedule_delayed_work(&cnet->ecache.dwork, delay);
} }
...@@ -199,7 +184,6 @@ int nf_conntrack_eventmask_report(unsigned int events, struct nf_conn *ct, ...@@ -199,7 +184,6 @@ int nf_conntrack_eventmask_report(unsigned int events, struct nf_conn *ct,
*/ */
if (e->portid == 0 && portid != 0) if (e->portid == 0 && portid != 0)
e->portid = portid; e->portid = portid;
e->state = NFCT_ECACHE_DESTROY_FAIL;
} }
return ret; return ret;
...@@ -297,8 +281,10 @@ void nf_conntrack_ecache_work(struct net *net, enum nf_ct_ecache_state state) ...@@ -297,8 +281,10 @@ void nf_conntrack_ecache_work(struct net *net, enum nf_ct_ecache_state state)
schedule_delayed_work(&cnet->ecache.dwork, HZ); schedule_delayed_work(&cnet->ecache.dwork, HZ);
net->ct.ecache_dwork_pending = true; net->ct.ecache_dwork_pending = true;
} else if (state == NFCT_ECACHE_DESTROY_SENT) { } else if (state == NFCT_ECACHE_DESTROY_SENT) {
net->ct.ecache_dwork_pending = false; if (!hlist_nulls_empty(&cnet->ecache.dying_list))
mod_delayed_work(system_wq, &cnet->ecache.dwork, 0); mod_delayed_work(system_wq, &cnet->ecache.dwork, 0);
else
net->ct.ecache_dwork_pending = false;
} }
} }
...@@ -311,8 +297,9 @@ void nf_conntrack_ecache_pernet_init(struct net *net) ...@@ -311,8 +297,9 @@ void nf_conntrack_ecache_pernet_init(struct net *net)
net->ct.sysctl_events = nf_ct_events; net->ct.sysctl_events = nf_ct_events;
cnet->ecache.ct_net = &net->ct;
INIT_DELAYED_WORK(&cnet->ecache.dwork, ecache_work); INIT_DELAYED_WORK(&cnet->ecache.dwork, ecache_work);
INIT_HLIST_NULLS_HEAD(&cnet->ecache.dying_list, DYING_NULLS_VAL);
spin_lock_init(&cnet->ecache.dying_lock);
BUILD_BUG_ON(__IPCT_MAX >= 16); /* e->ctmask is u16 */ BUILD_BUG_ON(__IPCT_MAX >= 16); /* e->ctmask is u16 */
} }
......
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