1 files changed, 69 insertions, 31 deletions

diff --git a/net/core/flow.c b/net/core/flow.c
index 521df52a77d2..161900674009 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -26,7 +26,10 @@
 #include <linux/security.h>
 
 struct flow_cache_entry {
-        struct flow_cache_entry         *next;
+        union {
+                struct hlist_node       hlist;
+                struct list_head        gc_list;
+        } u;
         u16                             family;
         u8                              dir;
         u32                             genid;
@@ -35,7 +38,7 @@ struct flow_cache_entry {
 };
 
 struct flow_cache_percpu {
-        struct flow_cache_entry         **hash_table;
+        struct hlist_head               *hash_table;
         int                             hash_count;
         u32                             hash_rnd;
         int                             hash_rnd_recalc;
@@ -62,6 +65,9 @@ atomic_t flow_cache_genid = ATOMIC_INIT(0);
 static struct flow_cache flow_cache_global;
 static struct kmem_cache *flow_cachep;
 
+static DEFINE_SPINLOCK(flow_cache_gc_lock);
+static LIST_HEAD(flow_cache_gc_list);
+
 #define flow_cache_hash_size(cache)     (1 << (cache)->hash_shift)
 #define FLOW_HASH_RND_PERIOD            (10 * 60 * HZ)
 
@@ -86,38 +92,66 @@ static int flow_entry_valid(struct flow_cache_entry *fle)
         return 1;
 }
 
-static void flow_entry_kill(struct flow_cache *fc,
-                            struct flow_cache_percpu *fcp,
-                            struct flow_cache_entry *fle)
+static void flow_entry_kill(struct flow_cache_entry *fle)
 {
         if (fle->object)
                 fle->object->ops->delete(fle->object);
         kmem_cache_free(flow_cachep, fle);
-        fcp->hash_count--;
+}
+
+static void flow_cache_gc_task(struct work_struct *work)
+{
+        struct list_head gc_list;
+        struct flow_cache_entry *fce, *n;
+
+        INIT_LIST_HEAD(&gc_list);
+        spin_lock_bh(&flow_cache_gc_lock);
+        list_splice_tail_init(&flow_cache_gc_list, &gc_list);
+        spin_unlock_bh(&flow_cache_gc_lock);
+
+        list_for_each_entry_safe(fce, n, &gc_list, u.gc_list)
+                flow_entry_kill(fce);
+}
+static DECLARE_WORK(flow_cache_gc_work, flow_cache_gc_task);
+
+static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp,
+                                     int deleted, struct list_head *gc_list)
+{
+        if (deleted) {
+                fcp->hash_count -= deleted;
+                spin_lock_bh(&flow_cache_gc_lock);
+                list_splice_tail(gc_list, &flow_cache_gc_list);
+                spin_unlock_bh(&flow_cache_gc_lock);
+                schedule_work(&flow_cache_gc_work);
+        }
 }
 
 static void __flow_cache_shrink(struct flow_cache *fc,
                                 struct flow_cache_percpu *fcp,
                                 int shrink_to)
 {
-        struct flow_cache_entry *fle, **flp;
-        int i;
+        struct flow_cache_entry *fle;
+        struct hlist_node *entry, *tmp;
+        LIST_HEAD(gc_list);
+        int i, deleted = 0;
 
         for (i = 0; i < flow_cache_hash_size(fc); i++) {
                 int saved = 0;
 
-                flp = &fcp->hash_table[i];
-                while ((fle = *flp) != NULL) {
+                hlist_for_each_entry_safe(fle, entry, tmp,
+                                          &fcp->hash_table[i], u.hlist) {
                         if (saved < shrink_to &&
                             flow_entry_valid(fle)) {
                                 saved++;
-                                flp = &fle->next;
                         } else {
-                                *flp = fle->next;
-                                flow_entry_kill(fc, fcp, fle);
+                                deleted++;
+                                hlist_del(&fle->u.hlist);
+                                list_add_tail(&fle->u.gc_list, &gc_list);
                         }
                 }
         }
+
+        flow_cache_queue_garbage(fcp, deleted, &gc_list);
 }
 
 static void flow_cache_shrink(struct flow_cache *fc,
@@ -182,7 +216,8 @@ flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
 {
         struct flow_cache *fc = &flow_cache_global;
         struct flow_cache_percpu *fcp;
-        struct flow_cache_entry *fle, **head;
+        struct flow_cache_entry *fle, *tfle;
+        struct hlist_node *entry;
         struct flow_cache_object *flo;
         unsigned int hash;
 
@@ -200,12 +235,13 @@ flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
                 flow_new_hash_rnd(fc, fcp);
 
         hash = flow_hash_code(fc, fcp, key);
-        head = &fcp->hash_table[hash];
-        for (fle = *head; fle; fle = fle->next) {
-                if (fle->family == family &&
-                    fle->dir == dir &&
-                    flow_key_compare(key, &fle->key) == 0)
+        hlist_for_each_entry(tfle, entry, &fcp->hash_table[hash], u.hlist) {
+                if (tfle->family == family &&
+                    tfle->dir == dir &&
+                    flow_key_compare(key, &tfle->key) == 0) {
+                        fle = tfle;
                         break;
+                }
         }
 
         if (unlikely(!fle)) {
@@ -214,12 +250,11 @@ flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
 
                 fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
                 if (fle) {
-                        fle->next = *head;
-                        *head = fle;
                         fle->family = family;
                         fle->dir = dir;
                         memcpy(&fle->key, key, sizeof(*key));
                         fle->object = NULL;
+                        hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]);
                         fcp->hash_count++;
                 }
         } else if (likely(fle->genid == atomic_read(&flow_cache_genid))) {
@@ -262,23 +297,26 @@ static void flow_cache_flush_tasklet(unsigned long data)
         struct flow_flush_info *info = (void *)data;
         struct flow_cache *fc = info->cache;
         struct flow_cache_percpu *fcp;
-        int i;
+        struct flow_cache_entry *fle;
+        struct hlist_node *entry, *tmp;
+        LIST_HEAD(gc_list);
+        int i, deleted = 0;
 
         fcp = per_cpu_ptr(fc->percpu, smp_processor_id());
         for (i = 0; i < flow_cache_hash_size(fc); i++) {
-                struct flow_cache_entry *fle;
-
-                fle = fcp->hash_table[i];
-                for (; fle; fle = fle->next) {
+                hlist_for_each_entry_safe(fle, entry, tmp,
+                                          &fcp->hash_table[i], u.hlist) {
                         if (flow_entry_valid(fle))
                                 continue;
 
-                        if (fle->object)
-                                fle->object->ops->delete(fle->object);
-                        fle->object = NULL;
+                        deleted++;
+                        hlist_del(&fle->u.hlist);
+                        list_add_tail(&fle->u.gc_list, &gc_list);
                 }
         }
 
+        flow_cache_queue_garbage(fcp, deleted, &gc_list);
+
         if (atomic_dec_and_test(&info->cpuleft))
                 complete(&info->completion);
 }
@@ -320,7 +358,7 @@ void flow_cache_flush(void)
 static void __init flow_cache_cpu_prepare(struct flow_cache *fc,
                                           struct flow_cache_percpu *fcp)
 {
-        fcp->hash_table = (struct flow_cache_entry **)
+        fcp->hash_table = (struct hlist_head *)
                 __get_free_pages(GFP_KERNEL|__GFP_ZERO, fc->order);
         if (!fcp->hash_table)
                 panic("NET: failed to allocate flow cache order %lu\n", fc->order);
@@ -354,7 +392,7 @@ static int flow_cache_init(struct flow_cache *fc)
 
         for (order = 0;
              (PAGE_SIZE << order) <
-                     (sizeof(struct flow_cache_entry *)*flow_cache_hash_size(fc));
+                     (sizeof(struct hlist_head)*flow_cache_hash_size(fc));
              order++)
                 /* NOTHING */;
         fc->order = order;