net: Use skb accessors in network core

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Matthew Wilcox (Oracle)

include/linux/skbuff.h

@@ -3166,7 +3166,7 @@ static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
 	if (skb_zcopy(skb))
 		return false;
 	if (i) {
-		const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
+		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
 
 		return page == skb_frag_page(frag) &&
 		       off == frag->page_offset + skb_frag_size(frag);

net/core/skbuff.c

@@ -2485,19 +2485,19 @@ int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
 	for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
 		skb_frag_t *frag  = &skb_shinfo(skb)->frags[fragidx];
 
-		if (offset < frag->size)
+		if (offset < skb_frag_size(frag))
 			break;
 
-		offset -= frag->size;
+		offset -= skb_frag_size(frag);
 	}
 
 	for (; len && fragidx < skb_shinfo(skb)->nr_frags; fragidx++) {
 		skb_frag_t *frag  = &skb_shinfo(skb)->frags[fragidx];
 
-		slen = min_t(size_t, len, frag->size - offset);
+		slen = min_t(size_t, len, skb_frag_size(frag) - offset);
 
 		while (slen) {
-			ret = kernel_sendpage_locked(sk, frag->page.p,
+			ret = kernel_sendpage_locked(sk, skb_frag_page(frag),
 						     frag->page_offset + offset,
 						     slen, MSG_DONTWAIT);
 			if (ret <= 0)
@@ -2975,11 +2975,15 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
 	skb_zerocopy_clone(to, from, GFP_ATOMIC);
 
 	for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
+		int size;
+
 		if (!len)
 			break;
 		skb_shinfo(to)->frags[j] = skb_shinfo(from)->frags[i];
-		skb_shinfo(to)->frags[j].size = min_t(int, skb_shinfo(to)->frags[j].size, len);
-		len -= skb_shinfo(to)->frags[j].size;
+		size = min_t(int, skb_frag_size(&skb_shinfo(to)->frags[j]),
+					len);
+		skb_frag_size_set(&skb_shinfo(to)->frags[j], size);
+		len -= size;
 		skb_frag_ref(to, j);
 		j++;
 	}
@@ -3293,7 +3297,7 @@ static int skb_prepare_for_shift(struct sk_buff *skb)
 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen)
 {
 	int from, to, merge, todo;
-	struct skb_frag_struct *fragfrom, *fragto;
+	skb_frag_t *fragfrom, *fragto;
 
 	BUG_ON(shiftlen > skb->len);
 
@@ -3625,10 +3629,10 @@ static inline skb_frag_t skb_head_frag_to_page_desc(struct sk_buff *frag_skb)
 	struct page *page;
 
 	page = virt_to_head_page(frag_skb->head);
-	head_frag.page.p = page;
+	__skb_frag_set_page(&head_frag, page);
 	head_frag.page_offset = frag_skb->data -
 		(unsigned char *)page_address(page);
-	head_frag.size = skb_headlen(frag_skb);
+	skb_frag_size_set(&head_frag, skb_headlen(frag_skb));
 	return head_frag;
 }
 
@@ -4021,7 +4025,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
 
 		pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags;
 
-		frag->page.p	  = page;
+		__skb_frag_set_page(frag, page);
 		frag->page_offset = first_offset;
 		skb_frag_size_set(frag, first_size);
 

net/core/tso.c

@@ -55,8 +55,8 @@ void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size)
 		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
 
 		/* Move to next segment */
-		tso->size = frag->size;
-		tso->data = page_address(frag->page.p) + frag->page_offset;
+		tso->size = skb_frag_size(frag);
+		tso->data = skb_frag_address(frag);
 		tso->next_frag_idx++;
 	}
 }
@@ -79,8 +79,8 @@ void tso_start(struct sk_buff *skb, struct tso_t *tso)
 		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
 
 		/* Move to next segment */
-		tso->size = frag->size;
-		tso->data = page_address(frag->page.p) + frag->page_offset;
+		tso->size = skb_frag_size(frag);
+		tso->data = skb_frag_address(frag);
 		tso->next_frag_idx++;
 	}
 }

net/ipv4/tcp.c

@@ -1776,19 +1776,21 @@ static int tcp_zerocopy_receive(struct sock *sk,
 				break;
 			frags = skb_shinfo(skb)->frags;
 			while (offset) {
-				if (frags->size > offset)
+				if (skb_frag_size(frags) > offset)
 					goto out;
-				offset -= frags->size;
+				offset -= skb_frag_size(frags);
 				frags++;
 			}
 		}
-		if (frags->size != PAGE_SIZE || frags->page_offset) {
+		if (skb_frag_size(frags) != PAGE_SIZE || frags->page_offset) {
 			int remaining = zc->recv_skip_hint;
+			int size = skb_frag_size(frags);
 
-			while (remaining && (frags->size != PAGE_SIZE ||
+			while (remaining && (size != PAGE_SIZE ||
 					     frags->page_offset)) {
-				remaining -= frags->size;
+				remaining -= size;
 				frags++;
+				size = skb_frag_size(frags);
 			}
 			zc->recv_skip_hint -= remaining;
 			break;
@@ -3781,7 +3783,7 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
 		return 1;
 
 	for (i = 0; i < shi->nr_frags; ++i) {
-		const struct skb_frag_struct *f = &shi->frags[i];
+		const skb_frag_t *f = &shi->frags[i];
 		unsigned int offset = f->page_offset;
 		struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
 

net/kcm/kcmsock.c

@@ -635,15 +635,15 @@ static int kcm_write_msgs(struct kcm_sock *kcm)
 			frag_offset = 0;
 do_frag:
 			frag = &skb_shinfo(skb)->frags[fragidx];
-			if (WARN_ON(!frag->size)) {
+			if (WARN_ON(!skb_frag_size(frag))) {
 				ret = -EINVAL;
 				goto out;
 			}
 
 			ret = kernel_sendpage(psock->sk->sk_socket,
-					      frag->page.p,
+					      skb_frag_page(frag),
 					      frag->page_offset + frag_offset,
-					      frag->size - frag_offset,
+					      skb_frag_size(frag) - frag_offset,
 					      MSG_DONTWAIT);
 			if (ret <= 0) {
 				if (ret == -EAGAIN) {
@@ -678,7 +678,7 @@ static int kcm_write_msgs(struct kcm_sock *kcm)
 			sent += ret;
 			frag_offset += ret;
 			KCM_STATS_ADD(psock->stats.tx_bytes, ret);
-			if (frag_offset < frag->size) {
+			if (frag_offset < skb_frag_size(frag)) {
 				/* Not finished with this frag */
 				goto do_frag;
 			}

net/tls/tls_device.c

@@ -243,14 +243,14 @@ static void tls_append_frag(struct tls_record_info *record,
 	skb_frag_t *frag;
 
 	frag = &record->frags[record->num_frags - 1];
-	if (frag->page.p == pfrag->page &&
-	    frag->page_offset + frag->size == pfrag->offset) {
-		frag->size += size;
+	if (skb_frag_page(frag) == pfrag->page &&
+	    frag->page_offset + skb_frag_size(frag) == pfrag->offset) {
+		skb_frag_size_add(frag, size);
 	} else {
 		++frag;
-		frag->page.p = pfrag->page;
+		__skb_frag_set_page(frag, pfrag->page);
 		frag->page_offset = pfrag->offset;
-		frag->size = size;
+		skb_frag_size_set(frag, size);
 		++record->num_frags;
 		get_page(pfrag->page);
 	}
@@ -301,8 +301,8 @@ static int tls_push_record(struct sock *sk,
 		frag = &record->frags[i];
 		sg_unmark_end(&offload_ctx->sg_tx_data[i]);
 		sg_set_page(&offload_ctx->sg_tx_data[i], skb_frag_page(frag),
-			    frag->size, frag->page_offset);
-		sk_mem_charge(sk, frag->size);
+			    skb_frag_size(frag), frag->page_offset);
+		sk_mem_charge(sk, skb_frag_size(frag));
 		get_page(skb_frag_page(frag));
 	}
 	sg_mark_end(&offload_ctx->sg_tx_data[record->num_frags - 1]);