[INET]: Collect frag queues management objects together

There are some objects that are common in all the places
which are used to keep track of frag queues, they are:

 * hash table
 * LRU list
 * rw lock
 * rnd number for hash function
 * the number of queues
 * the amount of memory occupied by queues
 * secret timer

Move all this stuff into one structure (struct inet_frags)
to make it possible use them uniformly in the future. Like
with the previous patch this mostly consists of hunks like

-    write_lock(&ipfrag_lock);
+    write_lock(&ip4_frags.lock);

To address the issue with exporting the number of queues and
the amount of memory occupied by queues outside the .c file
they are declared in, I introduce a couple of helpers.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 54 insertions, 56 deletions

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index aef5dd1ebc8a..ecf340047cde 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -87,15 +87,17 @@ struct frag_queue
         __u16                   nhoffset;
 };
 
-/* Hash table. */
+static struct inet_frags ip6_frags;
 
-#define IP6Q_HASHSZ     64
+int ip6_frag_nqueues(void)
+{
+        return ip6_frags.nqueues;
+}
 
-static struct hlist_head ip6_frag_hash[IP6Q_HASHSZ];
-static DEFINE_RWLOCK(ip6_frag_lock);
-static u32 ip6_frag_hash_rnd;
-static LIST_HEAD(ip6_frag_lru_list);
-int ip6_frag_nqueues = 0;
+int ip6_frag_mem(void)
+{
+        return atomic_read(&ip6_frags.mem);
+}
 
 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
                           struct net_device *dev);
@@ -104,14 +106,14 @@ static __inline__ void __fq_unlink(struct frag_queue *fq)
 {
         hlist_del(&fq->q.list);
         list_del(&fq->q.lru_list);
-        ip6_frag_nqueues--;
+        ip6_frags.nqueues--;
 }
 
 static __inline__ void fq_unlink(struct frag_queue *fq)
 {
-        write_lock(&ip6_frag_lock);
+        write_lock(&ip6_frags.lock);
         __fq_unlink(fq);
-        write_unlock(&ip6_frag_lock);
+        write_unlock(&ip6_frags.lock);
 }
 
 /*
@@ -129,7 +131,7 @@ static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
 
         a += JHASH_GOLDEN_RATIO;
         b += JHASH_GOLDEN_RATIO;
-        c += ip6_frag_hash_rnd;
+        c += ip6_frags.rnd;
         __jhash_mix(a, b, c);
 
         a += (__force u32)saddr->s6_addr32[3];
@@ -142,10 +144,9 @@ static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
         c += (__force u32)id;
         __jhash_mix(a, b, c);
 
-        return c & (IP6Q_HASHSZ - 1);
+        return c & (INETFRAGS_HASHSZ - 1);
 }
 
-static struct timer_list ip6_frag_secret_timer;
 int sysctl_ip6frag_secret_interval __read_mostly = 10 * 60 * HZ;
 
 static void ip6_frag_secret_rebuild(unsigned long dummy)
@@ -153,13 +154,13 @@ static void ip6_frag_secret_rebuild(unsigned long dummy)
         unsigned long now = jiffies;
         int i;
 
-        write_lock(&ip6_frag_lock);
-        get_random_bytes(&ip6_frag_hash_rnd, sizeof(u32));
-        for (i = 0; i < IP6Q_HASHSZ; i++) {
+        write_lock(&ip6_frags.lock);
+        get_random_bytes(&ip6_frags.rnd, sizeof(u32));
+        for (i = 0; i < INETFRAGS_HASHSZ; i++) {
                 struct frag_queue *q;
                 struct hlist_node *p, *n;
 
-                hlist_for_each_entry_safe(q, p, n, &ip6_frag_hash[i], q.list) {
+                hlist_for_each_entry_safe(q, p, n, &ip6_frags.hash[i], q.list) {
                         unsigned int hval = ip6qhashfn(q->id,
                                                        &q->saddr,
                                                        &q->daddr);
@@ -169,24 +170,22 @@ static void ip6_frag_secret_rebuild(unsigned long dummy)
 
                                 /* Relink to new hash chain. */
                                 hlist_add_head(&q->q.list,
-                                               &ip6_frag_hash[hval]);
+                                               &ip6_frags.hash[hval]);
 
                         }
                 }
         }
-        write_unlock(&ip6_frag_lock);
+        write_unlock(&ip6_frags.lock);
 
-        mod_timer(&ip6_frag_secret_timer, now + sysctl_ip6frag_secret_interval);
+        mod_timer(&ip6_frags.secret_timer, now + sysctl_ip6frag_secret_interval);
 }
 
-atomic_t ip6_frag_mem = ATOMIC_INIT(0);
-
 /* Memory Tracking Functions. */
 static inline void frag_kfree_skb(struct sk_buff *skb, int *work)
 {
         if (work)
                 *work -= skb->truesize;
-        atomic_sub(skb->truesize, &ip6_frag_mem);
+        atomic_sub(skb->truesize, &ip6_frags.mem);
         kfree_skb(skb);
 }
 
@@ -194,7 +193,7 @@ static inline void frag_free_queue(struct frag_queue *fq, int *work)
 {
         if (work)
                 *work -= sizeof(struct frag_queue);
-        atomic_sub(sizeof(struct frag_queue), &ip6_frag_mem);
+        atomic_sub(sizeof(struct frag_queue), &ip6_frags.mem);
         kfree(fq);
 }
 
@@ -204,7 +203,7 @@ static inline struct frag_queue *frag_alloc_queue(void)
 
         if(!fq)
                 return NULL;
-        atomic_add(sizeof(struct frag_queue), &ip6_frag_mem);
+        atomic_add(sizeof(struct frag_queue), &ip6_frags.mem);
         return fq;
 }
 
@@ -257,20 +256,20 @@ static void ip6_evictor(struct inet6_dev *idev)
         struct list_head *tmp;
         int work;
 
-        work = atomic_read(&ip6_frag_mem) - sysctl_ip6frag_low_thresh;
+        work = atomic_read(&ip6_frags.mem) - sysctl_ip6frag_low_thresh;
         if (work <= 0)
                 return;
 
         while(work > 0) {
-                read_lock(&ip6_frag_lock);
-                if (list_empty(&ip6_frag_lru_list)) {
-                        read_unlock(&ip6_frag_lock);
+                read_lock(&ip6_frags.lock);
+                if (list_empty(&ip6_frags.lru_list)) {
+                        read_unlock(&ip6_frags.lock);
                         return;
                 }
-                tmp = ip6_frag_lru_list.next;
+                tmp = ip6_frags.lru_list.next;
                 fq = list_entry(tmp, struct frag_queue, q.lru_list);
                 atomic_inc(&fq->q.refcnt);
-                read_unlock(&ip6_frag_lock);
+                read_unlock(&ip6_frags.lock);
 
                 spin_lock(&fq->q.lock);
                 if (!(fq->q.last_in&COMPLETE))
@@ -332,15 +331,15 @@ static struct frag_queue *ip6_frag_intern(struct frag_queue *fq_in)
         struct hlist_node *n;
 #endif
 
-        write_lock(&ip6_frag_lock);
+        write_lock(&ip6_frags.lock);
         hash = ip6qhashfn(fq_in->id, &fq_in->saddr, &fq_in->daddr);
 #ifdef CONFIG_SMP
-        hlist_for_each_entry(fq, n, &ip6_frag_hash[hash], q.list) {
+        hlist_for_each_entry(fq, n, &ip6_frags.hash[hash], q.list) {
                 if (fq->id == fq_in->id &&
                     ipv6_addr_equal(&fq_in->saddr, &fq->saddr) &&
                     ipv6_addr_equal(&fq_in->daddr, &fq->daddr)) {
                         atomic_inc(&fq->q.refcnt);
-                        write_unlock(&ip6_frag_lock);
+                        write_unlock(&ip6_frags.lock);
                         fq_in->q.last_in |= COMPLETE;
                         fq_put(fq_in, NULL);
                         return fq;
@@ -353,11 +352,11 @@ static struct frag_queue *ip6_frag_intern(struct frag_queue *fq_in)
                 atomic_inc(&fq->q.refcnt);
 
         atomic_inc(&fq->q.refcnt);
-        hlist_add_head(&fq->q.list, &ip6_frag_hash[hash]);
+        hlist_add_head(&fq->q.list, &ip6_frags.hash[hash]);
         INIT_LIST_HEAD(&fq->q.lru_list);
-        list_add_tail(&fq->q.lru_list, &ip6_frag_lru_list);
-        ip6_frag_nqueues++;
-        write_unlock(&ip6_frag_lock);
+        list_add_tail(&fq->q.lru_list, &ip6_frags.lru_list);
+        ip6_frags.nqueues++;
+        write_unlock(&ip6_frags.lock);
         return fq;
 }
 
@@ -396,18 +395,18 @@ fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst,
         struct hlist_node *n;
         unsigned int hash;
 
-        read_lock(&ip6_frag_lock);
+        read_lock(&ip6_frags.lock);
         hash = ip6qhashfn(id, src, dst);
-        hlist_for_each_entry(fq, n, &ip6_frag_hash[hash], q.list) {
+        hlist_for_each_entry(fq, n, &ip6_frags.hash[hash], q.list) {
                 if (fq->id == id &&
                     ipv6_addr_equal(src, &fq->saddr) &&
                     ipv6_addr_equal(dst, &fq->daddr)) {
                         atomic_inc(&fq->q.refcnt);
-                        read_unlock(&ip6_frag_lock);
+                        read_unlock(&ip6_frags.lock);
                         return fq;
                 }
         }
-        read_unlock(&ip6_frag_lock);
+        read_unlock(&ip6_frags.lock);
 
         return ip6_frag_create(id, src, dst, idev);
 }
@@ -565,7 +564,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
         }
         fq->q.stamp = skb->tstamp;
         fq->q.meat += skb->len;
-        atomic_add(skb->truesize, &ip6_frag_mem);
+        atomic_add(skb->truesize, &ip6_frags.mem);
 
         /* The first fragment.
          * nhoffset is obtained from the first fragment, of course.
@@ -578,9 +577,9 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
         if (fq->q.last_in == (FIRST_IN | LAST_IN) && fq->q.meat == fq->q.len)
                 return ip6_frag_reasm(fq, prev, dev);
 
-        write_lock(&ip6_frag_lock);
-        list_move_tail(&fq->q.lru_list, &ip6_frag_lru_list);
-        write_unlock(&ip6_frag_lock);
+        write_lock(&ip6_frags.lock);
+        list_move_tail(&fq->q.lru_list, &ip6_frags.lru_list);
+        write_unlock(&ip6_frags.lock);
         return -1;
 
 err:
@@ -659,7 +658,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
                 head->len -= clone->len;
                 clone->csum = 0;
                 clone->ip_summed = head->ip_summed;
-                atomic_add(clone->truesize, &ip6_frag_mem);
+                atomic_add(clone->truesize, &ip6_frags.mem);
         }
 
         /* We have to remove fragment header from datagram and to relocate
@@ -674,7 +673,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
         skb_shinfo(head)->frag_list = head->next;
         skb_reset_transport_header(head);
         skb_push(head, head->data - skb_network_header(head));
-        atomic_sub(head->truesize, &ip6_frag_mem);
+        atomic_sub(head->truesize, &ip6_frags.mem);
 
         for (fp=head->next; fp; fp = fp->next) {
                 head->data_len += fp->len;
@@ -684,7 +683,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
                 else if (head->ip_summed == CHECKSUM_COMPLETE)
                         head->csum = csum_add(head->csum, fp->csum);
                 head->truesize += fp->truesize;
-                atomic_sub(fp->truesize, &ip6_frag_mem);
+                atomic_sub(fp->truesize, &ip6_frags.mem);
         }
 
         head->next = NULL;
@@ -755,7 +754,7 @@ static int ipv6_frag_rcv(struct sk_buff **skbp)
                 return 1;
         }
 
-        if (atomic_read(&ip6_frag_mem) > sysctl_ip6frag_high_thresh)
+        if (atomic_read(&ip6_frags.mem) > sysctl_ip6frag_high_thresh)
                 ip6_evictor(ip6_dst_idev(skb->dst));
 
         if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr,
@@ -787,11 +786,10 @@ void __init ipv6_frag_init(void)
         if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0)
                 printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n");
 
-        ip6_frag_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
-                                   (jiffies ^ (jiffies >> 6)));
+        init_timer(&ip6_frags.secret_timer);
+        ip6_frags.secret_timer.function = ip6_frag_secret_rebuild;
+        ip6_frags.secret_timer.expires = jiffies + sysctl_ip6frag_secret_interval;
+        add_timer(&ip6_frags.secret_timer);
 
-        init_timer(&ip6_frag_secret_timer);
-        ip6_frag_secret_timer.function = ip6_frag_secret_rebuild;
-        ip6_frag_secret_timer.expires = jiffies + sysctl_ip6frag_secret_interval;
-        add_timer(&ip6_frag_secret_timer);
+        inet_frags_init(&ip6_frags);
 }