Merge branch 'writeback-for-linus' of git://github.com/fengguang/linux

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

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 27002df..387703f 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -611,8 +611,21 @@ struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src)
 }
 EXPORT_SYMBOL_GPL(skb_morph);
 
-/* skb frags copy userspace buffers to kernel */
-static int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
+/*     skb_copy_ubufs  -       copy userspace skb frags buffers to kernel
+ *     @skb: the skb to modify
+ *     @gfp_mask: allocation priority
+ *
+ *     This must be called on SKBTX_DEV_ZEROCOPY skb.
+ *     It will copy all frags into kernel and drop the reference
+ *     to userspace pages.
+ *
+ *     If this function is called from an interrupt gfp_mask() must be
+ *     %GFP_ATOMIC.
+ *
+ *     Returns 0 on success or a negative error code on failure
+ *     to allocate kernel memory to copy to.
+ */
+int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 {
        int i;
        int num_frags = skb_shinfo(skb)->nr_frags;
@@ -652,6 +665,8 @@ static int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
                skb_shinfo(skb)->frags[i - 1].page = head;
                head = (struct page *)head->private;
        }
+
+       skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
        return 0;
 }
 
@@ -677,7 +692,6 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
        if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
                if (skb_copy_ubufs(skb, gfp_mask))
                        return NULL;
-               skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
        }
 
        n = skb + 1;
@@ -803,7 +817,6 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
                                n = NULL;
                                goto out;
                        }
-                       skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
                }
                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
                        skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i];
@@ -896,7 +909,6 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
                if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
                        if (skb_copy_ubufs(skb, gfp_mask))
                                goto nofrags;
-                       skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
                }
                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
                        get_page(skb_shinfo(skb)->frags[i].page);