1 files changed, 44 insertions, 48 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c83b421341c..752c1972b3a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -202,8 +202,6 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
         skb->data = data;
         skb_reset_tail_pointer(skb);
         skb->end = skb->tail + size;
-        kmemcheck_annotate_bitfield(skb, flags1);
-        kmemcheck_annotate_bitfield(skb, flags2);
 #ifdef NET_SKBUFF_DATA_USES_OFFSET
         skb->mac_header = ~0U;
 #endif
@@ -340,7 +338,7 @@ static void skb_release_data(struct sk_buff *skb)
                                 put_page(skb_shinfo(skb)->frags[i].page);
                 }
 
-                if (skb_has_frags(skb))
+                if (skb_has_frag_list(skb))
                         skb_drop_fraglist(skb);
 
                 kfree(skb->head);
@@ -685,16 +683,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
 
 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
 {
-        int headerlen = skb->data - skb->head;
-        /*
-         *      Allocate the copy buffer
-         */
-        struct sk_buff *n;
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        n = alloc_skb(skb->end + skb->data_len, gfp_mask);
-#else
-        n = alloc_skb(skb->end - skb->head + skb->data_len, gfp_mask);
-#endif
+        int headerlen = skb_headroom(skb);
+        unsigned int size = (skb_end_pointer(skb) - skb->head) + skb->data_len;
+        struct sk_buff *n = alloc_skb(size, gfp_mask);
+
         if (!n)
                 return NULL;
 
@@ -726,20 +718,14 @@ EXPORT_SYMBOL(skb_copy);
 
 struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
 {
-        /*
-         *      Allocate the copy buffer
-         */
-        struct sk_buff *n;
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        n = alloc_skb(skb->end, gfp_mask);
-#else
-        n = alloc_skb(skb->end - skb->head, gfp_mask);
-#endif
+        unsigned int size = skb_end_pointer(skb) - skb->head;
+        struct sk_buff *n = alloc_skb(size, gfp_mask);
+
         if (!n)
                 goto out;
 
         /* Set the data pointer */
-        skb_reserve(n, skb->data - skb->head);
+        skb_reserve(n, skb_headroom(skb));
         /* Set the tail pointer and length */
         skb_put(n, skb_headlen(skb));
         /* Copy the bytes */
@@ -759,7 +745,7 @@ struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask)
                 skb_shinfo(n)->nr_frags = i;
         }
 
-        if (skb_has_frags(skb)) {
+        if (skb_has_frag_list(skb)) {
                 skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list;
                 skb_clone_fraglist(n);
         }
@@ -791,12 +777,9 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
 {
         int i;
         u8 *data;
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        int size = nhead + skb->end + ntail;
-#else
-        int size = nhead + (skb->end - skb->head) + ntail;
-#endif
+        int size = nhead + (skb_end_pointer(skb) - skb->head) + ntail;
         long off;
+        bool fastpath;
 
         BUG_ON(nhead < 0);
 
@@ -810,23 +793,36 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
                 goto nodata;
 
         /* Copy only real data... and, alas, header. This should be
-         * optimized for the cases when header is void. */
-#ifdef NET_SKBUFF_DATA_USES_OFFSET
-        memcpy(data + nhead, skb->head, skb->tail);
-#else
-        memcpy(data + nhead, skb->head, skb->tail - skb->head);
-#endif
-        memcpy(data + size, skb_end_pointer(skb),
+         * optimized for the cases when header is void.
+         */
+        memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);
+
+        memcpy((struct skb_shared_info *)(data + size),
+               skb_shinfo(skb),
                offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags]));
 
-        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
-                get_page(skb_shinfo(skb)->frags[i].page);
+        /* Check if we can avoid taking references on fragments if we own
+         * the last reference on skb->head. (see skb_release_data())
+         */
+        if (!skb->cloned)
+                fastpath = true;
+        else {
+                int delta = skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1;
 
-        if (skb_has_frags(skb))
-                skb_clone_fraglist(skb);
+                fastpath = atomic_read(&skb_shinfo(skb)->dataref) == delta;
+        }
 
-        skb_release_data(skb);
+        if (fastpath) {
+                kfree(skb->head);
+        } else {
+                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+                        get_page(skb_shinfo(skb)->frags[i].page);
 
+                if (skb_has_frag_list(skb))
+                        skb_clone_fraglist(skb);
+
+                skb_release_data(skb);
+        }
         off = (data + nhead) - skb->head;
 
         skb->head     = data;
@@ -1099,7 +1095,7 @@ drop_pages:
                 for (; i < nfrags; i++)
                         put_page(skb_shinfo(skb)->frags[i].page);
 
-                if (skb_has_frags(skb))
+                if (skb_has_frag_list(skb))
                         skb_drop_fraglist(skb);
                 goto done;
         }
@@ -1194,7 +1190,7 @@ unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta)
         /* Optimization: no fragments, no reasons to preestimate
          * size of pulled pages. Superb.
          */
-        if (!skb_has_frags(skb))
+        if (!skb_has_frag_list(skb))
                 goto pull_pages;
 
         /* Estimate size of pulled pages. */
@@ -2323,7 +2319,7 @@ next_skb:
                 st->frag_data = NULL;
         }
 
-        if (st->root_skb == st->cur_skb && skb_has_frags(st->root_skb)) {
+        if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) {
                 st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
                 st->frag_idx = 0;
                 goto next_skb;
@@ -2893,7 +2889,7 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
                 return -ENOMEM;
 
         /* Easy case. Most of packets will go this way. */
-        if (!skb_has_frags(skb)) {
+        if (!skb_has_frag_list(skb)) {
                 /* A little of trouble, not enough of space for trailer.
                  * This should not happen, when stack is tuned to generate
                  * good frames. OK, on miss we reallocate and reserve even more
@@ -2928,7 +2924,7 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
 
                 if (skb1->next == NULL && tailbits) {
                         if (skb_shinfo(skb1)->nr_frags ||
-                            skb_has_frags(skb1) ||
+                            skb_has_frag_list(skb1) ||
                             skb_tailroom(skb1) < tailbits)
                                 ntail = tailbits + 128;
                 }
@@ -2937,7 +2933,7 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
                     skb_cloned(skb1) ||
                     ntail ||
                     skb_shinfo(skb1)->nr_frags ||
-                    skb_has_frags(skb1)) {
+                    skb_has_frag_list(skb1)) {
                         struct sk_buff *skb2;
 
                         /* Fuck, we are miserable poor guys... */
@@ -3020,7 +3016,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
         } else {
                 /*
                  * no hardware time stamps available,
-                 * so keep the skb_shared_tx and only
+                 * so keep the shared tx_flags and only
                  * store software time stamp
                  */
                 skb->tstamp = ktime_get_real();