1 files changed, 63 insertions, 7 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 15d47d5e7951..ecbba0abd3e5 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1742,14 +1742,48 @@ int tcp_mmap(struct file *file, struct socket *sock,
 }
 EXPORT_SYMBOL(tcp_mmap);
 
+static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
+					struct page **pages,
+					unsigned long pages_to_map,
+					unsigned long *insert_addr,
+					u32 *length_with_pending,
+					u32 *seq,
+					struct tcp_zerocopy_receive *zc)
+{
+	unsigned long pages_remaining = pages_to_map;
+	int bytes_mapped;
+	int ret;
+
+	ret = vm_insert_pages(vma, *insert_addr, pages, &pages_remaining);
+	bytes_mapped = PAGE_SIZE * (pages_to_map - pages_remaining);
+	/* Even if vm_insert_pages fails, it may have partially succeeded in
+	 * mapping (some but not all of the pages).
+	 */
+	*seq += bytes_mapped;
+	*insert_addr += bytes_mapped;
+	if (ret) {
+		/* But if vm_insert_pages did fail, we have to unroll some state
+		 * we speculatively touched before.
+		 */
+		const int bytes_not_mapped = PAGE_SIZE * pages_remaining;
+		*length_with_pending -= bytes_not_mapped;
+		zc->recv_skip_hint += bytes_not_mapped;
+	}
+	return ret;
+}
+
 static int tcp_zerocopy_receive(struct sock *sk,
 				struct tcp_zerocopy_receive *zc)
 {
 	unsigned long address = (unsigned long)zc->address;
 	u32 length = 0, seq, offset, zap_len;
+	#define PAGE_BATCH_SIZE 8
+	struct page *pages[PAGE_BATCH_SIZE];
 	const skb_frag_t *frags = NULL;
 	struct vm_area_struct *vma;
 	struct sk_buff *skb = NULL;
+	unsigned long pg_idx = 0;
+	unsigned long curr_addr;
 	struct tcp_sock *tp;
 	int inq;
 	int ret;
@@ -1762,6 +1796,8 @@ static int tcp_zerocopy_receive(struct sock *sk,
 
 	sock_rps_record_flow(sk);
 
+	tp = tcp_sk(sk);
+
 	down_read(&current->mm->mmap_sem);
 
 	vma = find_vma(current->mm, address);
@@ -1771,7 +1807,6 @@ static int tcp_zerocopy_receive(struct sock *sk,
 	}
 	zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);
 
-	tp = tcp_sk(sk);
 	seq = tp->copied_seq;
 	inq = tcp_inq(sk);
 	zc->length = min_t(u32, zc->length, inq);
@@ -1783,8 +1818,20 @@ static int tcp_zerocopy_receive(struct sock *sk,
 		zc->recv_skip_hint = zc->length;
 	}
 	ret = 0;
+	curr_addr = address;
 	while (length + PAGE_SIZE <= zc->length) {
 		if (zc->recv_skip_hint < PAGE_SIZE) {
+			/* If we're here, finish the current batch. */
+			if (pg_idx) {
+				ret = tcp_zerocopy_vm_insert_batch(vma, pages,
+								   pg_idx,
+								   &curr_addr,
+								   &length,
+								   &seq, zc);
+				if (ret)
+					goto out;
+				pg_idx = 0;
+			}
 			if (skb) {
 				if (zc->recv_skip_hint > 0)
 					break;
@@ -1793,7 +1840,6 @@ static int tcp_zerocopy_receive(struct sock *sk,
 			} else {
 				skb = tcp_recv_skb(sk, seq, &offset);
 			}
-
 			zc->recv_skip_hint = skb->len - offset;
 			offset -= skb_headlen(skb);
 			if ((int)offset < 0 || skb_has_frag_list(skb))
@@ -1817,14 +1863,24 @@ static int tcp_zerocopy_receive(struct sock *sk,
 			zc->recv_skip_hint -= remaining;
 			break;
 		}
-		ret = vm_insert_page(vma, address + length,
-				     skb_frag_page(frags));
-		if (ret)
-			break;
+		pages[pg_idx] = skb_frag_page(frags);
+		pg_idx++;
 		length += PAGE_SIZE;
-		seq += PAGE_SIZE;
 		zc->recv_skip_hint -= PAGE_SIZE;
 		frags++;
+		if (pg_idx == PAGE_BATCH_SIZE) {
+			ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx,
+							   &curr_addr, &length,
+							   &seq, zc);
+			if (ret)
+				goto out;
+			pg_idx = 0;
+		}
+	}
+	if (pg_idx) {
+		ret = tcp_zerocopy_vm_insert_batch(vma, pages, pg_idx,
+						   &curr_addr, &length, &seq,
+						   zc);
 	}
 out:
 	up_read(&current->mm->mmap_sem);