Merge gregkh@master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6

[pandora-kernel.git] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 44f6a18..c54f366 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -70,13 +70,6 @@
 static kmem_cache_t *skbuff_head_cache __read_mostly;
 static kmem_cache_t *skbuff_fclone_cache __read_mostly;
 
-/*
- * lockdep: lock class key used by skb_queue_head_init():
- */
-struct lock_class_key skb_queue_lock_key;
-
-EXPORT_SYMBOL(skb_queue_lock_key);
-
 /*
  *     Keep out-of-line to prevent kernel bloat.
  *     __builtin_return_address is not used because it is not always
@@ -256,12 +249,37 @@ nodata:
        goto out;
 }
 
+/**
+ *     __netdev_alloc_skb - allocate an skbuff for rx on a specific device
+ *     @dev: network device to receive on
+ *     @length: length to allocate
+ *     @gfp_mask: get_free_pages mask, passed to alloc_skb
+ *
+ *     Allocate a new &sk_buff and assign it a usage count of one. The
+ *     buffer has unspecified headroom built in. Users should allocate
+ *     the headroom they think they need without accounting for the
+ *     built in space. The built in space is used for optimisations.
+ *
+ *     %NULL is returned if there is no free memory.
+ */
+struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
+               unsigned int length, gfp_t gfp_mask)
+{
+       struct sk_buff *skb;
 
-static void skb_drop_fraglist(struct sk_buff *skb)
+       skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
+       if (likely(skb)) {
+               skb_reserve(skb, NET_SKB_PAD);
+               skb->dev = dev;
+       }
+       return skb;
+}
+
+static void skb_drop_list(struct sk_buff **listp)
 {
-       struct sk_buff *list = skb_shinfo(skb)->frag_list;
+       struct sk_buff *list = *listp;
 
-       skb_shinfo(skb)->frag_list = NULL;
+       *listp = NULL;
 
        do {
                struct sk_buff *this = list;
@@ -270,6 +288,11 @@ static void skb_drop_fraglist(struct sk_buff *skb)
        } while (list);
 }
 
+static inline void skb_drop_fraglist(struct sk_buff *skb)
+{
+       skb_drop_list(&skb_shinfo(skb)->frag_list);
+}
+
 static void skb_clone_fraglist(struct sk_buff *skb)
 {
        struct sk_buff *list;
@@ -830,41 +853,81 @@ free_skb:
 
 int ___pskb_trim(struct sk_buff *skb, unsigned int len)
 {
+       struct sk_buff **fragp;
+       struct sk_buff *frag;
        int offset = skb_headlen(skb);
        int nfrags = skb_shinfo(skb)->nr_frags;
        int i;
+       int err;
 
-       for (i = 0; i < nfrags; i++) {
+       if (skb_cloned(skb) &&
+           unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))))
+               return err;
+
+       i = 0;
+       if (offset >= len)
+               goto drop_pages;
+
+       for (; i < nfrags; i++) {
                int end = offset + skb_shinfo(skb)->frags[i].size;
-               if (end > len) {
-                       if (skb_cloned(skb)) {
-                               if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
-                                       return -ENOMEM;
-                       }
-                       if (len <= offset) {
-                               put_page(skb_shinfo(skb)->frags[i].page);
-                               skb_shinfo(skb)->nr_frags--;
-                       } else {
-                               skb_shinfo(skb)->frags[i].size = len - offset;
-                       }
+
+               if (end < len) {
+                       offset = end;
+                       continue;
                }
-               offset = end;
+
+               skb_shinfo(skb)->frags[i++].size = len - offset;
+
+drop_pages:
+               skb_shinfo(skb)->nr_frags = i;
+
+               for (; i < nfrags; i++)
+                       put_page(skb_shinfo(skb)->frags[i].page);
+
+               if (skb_shinfo(skb)->frag_list)
+                       skb_drop_fraglist(skb);
+               goto done;
        }
 
-       if (offset < len) {
+       for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp);
+            fragp = &frag->next) {
+               int end = offset + frag->len;
+
+               if (skb_shared(frag)) {
+                       struct sk_buff *nfrag;
+
+                       nfrag = skb_clone(frag, GFP_ATOMIC);
+                       if (unlikely(!nfrag))
+                               return -ENOMEM;
+
+                       nfrag->next = frag->next;
+                       kfree_skb(frag);
+                       frag = nfrag;
+                       *fragp = frag;
+               }
+
+               if (end < len) {
+                       offset = end;
+                       continue;
+               }
+
+               if (end > len &&
+                   unlikely((err = pskb_trim(frag, len - offset))))
+                       return err;
+
+               if (frag->next)
+                       skb_drop_list(&frag->next);
+               break;
+       }
+
+done:
+       if (len > skb_headlen(skb)) {
                skb->data_len -= skb->len - len;
                skb->len       = len;
        } else {
-               if (len <= skb_headlen(skb)) {
-                       skb->len      = len;
-                       skb->data_len = 0;
-                       skb->tail     = skb->data + len;
-                       if (skb_shinfo(skb)->frag_list && !skb_cloned(skb))
-                               skb_drop_fraglist(skb);
-               } else {
-                       skb->data_len -= skb->len - len;
-                       skb->len       = len;
-               }
+               skb->len       = len;
+               skb->data_len  = 0;
+               skb->tail      = skb->data + len;
        }
 
        return 0;
@@ -2003,6 +2066,7 @@ EXPORT_SYMBOL(__kfree_skb);
 EXPORT_SYMBOL(kfree_skb);
 EXPORT_SYMBOL(__pskb_pull_tail);
 EXPORT_SYMBOL(__alloc_skb);
+EXPORT_SYMBOL(__netdev_alloc_skb);
 EXPORT_SYMBOL(pskb_copy);
 EXPORT_SYMBOL(pskb_expand_head);
 EXPORT_SYMBOL(skb_checksum);