On Sun, Jun 08, 2003 at 01:54:26AM -0700, David S. Miller wrote:
>
> I'll be more than happy to review and fixup whatever you
> come up with.
OK, here is a patch based on my previous way with the destroyer element.
Please let me know what you think.
Thanks,
--
Debian GNU/Linux 3.0 is out! ( http://www.debian.org/ )
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
Index: kernel-source-2.5/include/net/flow.h
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/include/net/flow.h,v
retrieving revision 1.1.1.3
diff -u -r1.1.1.3 flow.h
--- kernel-source-2.5/include/net/flow.h 27 May 2003 08:38:39 -0000 1.1.1.3
+++ kernel-source-2.5/include/net/flow.h 9 Jun 2003 00:21:19 -0000
@@ -82,11 +82,14 @@
#define FLOW_DIR_OUT 1
#define FLOW_DIR_FWD 2
+typedef void (*flow_obj_destroy_t)(void *);
typedef void (*flow_resolve_t)(struct flowi *key, u16 family, u8 dir,
- void **objp, atomic_t **obj_refp);
+ void **objp, atomic_t **obj_refp,
+ flow_obj_destroy_t *destroyer);
extern void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
flow_resolve_t resolver);
+extern void flow_cache_flush(void *object);
extern atomic_t flow_cache_genid;
#endif
Index: kernel-source-2.5/include/net/xfrm.h
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/include/net/xfrm.h,v
retrieving revision 1.3
diff -u -r1.3 xfrm.h
--- kernel-source-2.5/include/net/xfrm.h 7 Jun 2003 09:36:28 -0000 1.3
+++ kernel-source-2.5/include/net/xfrm.h 9 Jun 2003 00:21:19 -0000
@@ -349,7 +349,7 @@
atomic_inc(&policy->refcnt);
}
-extern void __xfrm_policy_destroy(struct xfrm_policy *policy);
+extern void __xfrm_policy_destroy(void *policy);
static inline void xfrm_pol_put(struct xfrm_policy *policy)
{
Index: kernel-source-2.5/net/core/flow.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/net/core/flow.c,v
retrieving revision 1.3
diff -u -r1.3 flow.c
--- kernel-source-2.5/net/core/flow.c 2 Jun 2003 10:55:50 -0000 1.3
+++ kernel-source-2.5/net/core/flow.c 9 Jun 2003 01:10:19 -0000
@@ -12,6 +12,8 @@
#include <linux/random.h>
#include <linux/init.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
#include <net/flow.h>
#include <asm/atomic.h>
@@ -19,10 +21,13 @@
struct flow_cache_entry *next;
u16 family;
u8 dir;
+ u8 dead;
struct flowi key;
u32 genid;
void *object;
atomic_t *object_ref;
+ flow_obj_destroy_t object_destroy;
+ struct rcu_head rcu;
};
atomic_t flow_cache_genid = ATOMIC_INIT(0);
@@ -33,6 +38,7 @@
static kmem_cache_t *flow_cachep;
static int flow_lwm, flow_hwm;
+static spinlock_t flow_cache_lock = SPIN_LOCK_UNLOCKED;
struct flow_percpu_info {
int hash_rnd_recalc;
@@ -75,10 +81,14 @@
}
while ((fle = *flp) != NULL) {
*flp = fle->next;
+ flow_count(cpu)--;
+ if (fle->dead) {
+ fle->dead++;
+ continue;
+ }
if (fle->object)
atomic_dec(fle->object_ref);
kmem_cache_free(flow_cachep, fle);
- flow_count(cpu)--;
}
}
}
@@ -142,18 +152,20 @@
void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
flow_resolve_t resolver)
{
- struct flow_cache_entry *fle, **head;
+ struct flow_cache_entry *fle, **flp, **head;
unsigned int hash;
int cpu;
local_bh_disable();
+ rcu_read_lock();
+
cpu = smp_processor_id();
if (flow_hash_rnd_recalc(cpu))
flow_new_hash_rnd(cpu);
hash = flow_hash_code(key, cpu);
head = &flow_table[(cpu << flow_hash_shift) + hash];
- for (fle = *head; fle; fle = fle->next) {
+ for (flp = head; (fle = *flp) != NULL; flp = &fle->next) {
if (fle->family == family &&
fle->dir == dir &&
flow_key_compare(key, &fle->key) == 0) {
@@ -162,6 +174,8 @@
if (ret)
atomic_inc(fle->object_ref);
+
+ rcu_read_unlock();
local_bh_enable();
return ret;
@@ -173,8 +187,18 @@
{
void *obj;
atomic_t *obj_ref;
+ flow_obj_destroy_t obj_destroy;
+
+ resolver(key, family, dir, &obj, &obj_ref, &obj_destroy);
- resolver(key, family, dir, &obj, &obj_ref);
+ spin_lock(&flow_cache_lock);
+
+ if (fle && fle->dead) {
+ flow_count(cpu)--;
+ *flp = fle->next;
+ fle->dead++;
+ fle = NULL;
+ }
if (fle) {
fle->genid = atomic_read(&flow_cache_genid);
@@ -184,6 +208,8 @@
fle->object = obj;
fle->object_ref = obj_ref;
+ fle->object_destroy = obj_destroy;
+
if (obj)
atomic_inc(fle->object_ref);
} else {
@@ -198,18 +224,65 @@
fle->dir = dir;
memcpy(&fle->key, key, sizeof(*key));
fle->genid = atomic_read(&flow_cache_genid);
+ fle->dead = 0;
fle->object = obj;
fle->object_ref = obj_ref;
+ fle->object_destroy = obj_destroy;
+
if (obj)
atomic_inc(fle->object_ref);
flow_count(cpu)++;
}
}
+
+ spin_unlock(&flow_cache_lock);
+ rcu_read_unlock();
local_bh_enable();
return obj;
}
+}
+
+static void flow_drop_ref(void *data)
+{
+ struct flow_cache_entry *fle = data;
+ unsigned dead;
+
+ if (atomic_dec_and_test(fle->object_ref))
+ fle->object_destroy(fle->object);
+
+ spin_lock_bh(&flow_cache_lock);
+ dead = fle->dead;
+ fle->dead = 0;
+ spin_unlock_bh(&flow_cache_lock);
+
+ if (dead <= 1)
+ return;
+
+ kmem_cache_free(flow_cachep, fle);
+}
+
+void flow_cache_flush(void *object)
+{
+ int i;
+
+ spin_lock_bh(&flow_cache_lock);
+
+ for (i = 0; i < NR_CPUS * flow_hash_size; i++) {
+ struct flow_cache_entry *fle, **flp;
+
+ flp = &flow_table[i];
+ for (; (fle = *flp) != NULL; flp = &fle->next) {
+ if (fle->object != object)
+ continue;
+
+ fle->dead = 1;
+ call_rcu(&fle->rcu, flow_drop_ref, fle);
+ }
+ }
+
+ spin_unlock_bh(&flow_cache_lock);
}
static int __init flow_cache_init(void)
Index: kernel-source-2.5/net/xfrm/xfrm_policy.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/net/xfrm/xfrm_policy.c,v
retrieving revision 1.5
diff -u -r1.5 xfrm_policy.c
--- kernel-source-2.5/net/xfrm/xfrm_policy.c 7 Jun 2003 09:36:28 -0000 1.5
+++ kernel-source-2.5/net/xfrm/xfrm_policy.c 9 Jun 2003 00:21:19 -0000
@@ -180,8 +180,10 @@
/* Destroy xfrm_policy: descendant resources must be released to this moment. */
-void __xfrm_policy_destroy(struct xfrm_policy *policy)
+void __xfrm_policy_destroy(void *data)
{
+ struct xfrm_policy *policy = data;
+
if (!policy->dead)
BUG();
@@ -216,6 +218,8 @@
if (del_timer(&policy->timer))
atomic_dec(&policy->refcnt);
+ flow_cache_flush(policy);
+
out:
write_unlock_bh(&policy->lock);
}
@@ -388,8 +392,9 @@
/* Find policy to apply to this flow. */
-void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
- void **objp, atomic_t **obj_refp)
+static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
+ void **objp, atomic_t **obj_refp,
+ flow_obj_destroy_t *obj_destroyp)
{
struct xfrm_policy *pol;
@@ -408,8 +413,10 @@
}
}
read_unlock_bh(&xfrm_policy_lock);
- if ((*objp = (void *) pol) != NULL)
+ if ((*objp = (void *) pol) != NULL) {
*obj_refp = &pol->refcnt;
+ *obj_destroyp = __xfrm_policy_destroy;
+ }
}
struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl)
