1 files changed, 95 insertions, 92 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 735a209d4072..0292162a14ee 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -142,22 +142,33 @@ static void mptcp_drop(struct sock *sk, struct sk_buff *skb)
 	__kfree_skb(skb);
 }
 
-static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
-			       struct sk_buff *from)
+static bool __mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
+				 struct sk_buff *from, bool *fragstolen,
+				 int *delta)
 {
-	bool fragstolen;
-	int delta;
+	int limit = READ_ONCE(sk->sk_rcvbuf);
 
 	if (unlikely(MPTCP_SKB_CB(to)->cant_coalesce) ||
 	    MPTCP_SKB_CB(from)->offset ||
-	    ((to->len + from->len) > (sk->sk_rcvbuf >> 3)) ||
-	    !skb_try_coalesce(to, from, &fragstolen, &delta))
+	    ((to->len + from->len) > (limit >> 3)) ||
+	    !skb_try_coalesce(to, from, fragstolen, delta))
 		return false;
 
 	pr_debug("colesced seq %llx into %llx new len %d new end seq %llx\n",
 		 MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq,
 		 to->len, MPTCP_SKB_CB(from)->end_seq);
 	MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq;
+	return true;
+}
+
+static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to,
+			       struct sk_buff *from)
+{
+	bool fragstolen;
+	int delta;
+
+	if (!__mptcp_try_coalesce(sk, to, from, &fragstolen, &delta))
+		return false;
 
 	/* note the fwd memory can reach a negative value after accounting
 	 * for the delta, but the later skb free will restore a non
@@ -179,6 +190,35 @@ static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to,
 	return mptcp_try_coalesce((struct sock *)msk, to, from);
 }
 
+/* "inspired" by tcp_rcvbuf_grow(), main difference:
+ * - mptcp does not maintain a msk-level window clamp
+ * - returns true when  the receive buffer is actually updated
+ */
+static bool mptcp_rcvbuf_grow(struct sock *sk)
+{
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	const struct net *net = sock_net(sk);
+	int rcvwin, rcvbuf, cap;
+
+	if (!READ_ONCE(net->ipv4.sysctl_tcp_moderate_rcvbuf) ||
+	    (sk->sk_userlocks & SOCK_RCVBUF_LOCK))
+		return false;
+
+	rcvwin = msk->rcvq_space.space << 1;
+
+	if (!RB_EMPTY_ROOT(&msk->out_of_order_queue))
+		rcvwin += MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq - msk->ack_seq;
+
+	cap = READ_ONCE(net->ipv4.sysctl_tcp_rmem[2]);
+
+	rcvbuf = min_t(u32, mptcp_space_from_win(sk, rcvwin), cap);
+	if (rcvbuf > sk->sk_rcvbuf) {
+		WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
+		return true;
+	}
+	return false;
+}
+
 /* "inspired" by tcp_data_queue_ofo(), main differences:
  * - use mptcp seqs
  * - don't cope with sacks
@@ -292,29 +332,16 @@ merge_right:
 end:
 	skb_condense(skb);
 	skb_set_owner_r(skb, sk);
+	/* do not grow rcvbuf for not-yet-accepted or orphaned sockets. */
+	if (sk->sk_socket)
+		mptcp_rcvbuf_grow(sk);
 }
 
-static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
-			     struct sk_buff *skb, unsigned int offset,
-			     size_t copy_len)
+static void mptcp_init_skb(struct sock *ssk, struct sk_buff *skb, int offset,
+			   int copy_len)
 {
-	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
-	struct sock *sk = (struct sock *)msk;
-	struct sk_buff *tail;
-	bool has_rxtstamp;
-
-	__skb_unlink(skb, &ssk->sk_receive_queue);
-
-	skb_ext_reset(skb);
-	skb_orphan(skb);
-
-	/* try to fetch required memory from subflow */
-	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
-		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
-		goto drop;
-	}
-
-	has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
+	const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
+	bool has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp;
 
 	/* the skb map_seq accounts for the skb offset:
 	 * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq
@@ -326,6 +353,24 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
 	MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp;
 	MPTCP_SKB_CB(skb)->cant_coalesce = 0;
 
+	__skb_unlink(skb, &ssk->sk_receive_queue);
+
+	skb_ext_reset(skb);
+	skb_dst_drop(skb);
+}
+
+static bool __mptcp_move_skb(struct sock *sk, struct sk_buff *skb)
+{
+	u64 copy_len = MPTCP_SKB_CB(skb)->end_seq - MPTCP_SKB_CB(skb)->map_seq;
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct sk_buff *tail;
+
+	/* try to fetch required memory from subflow */
+	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
+		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED);
+		goto drop;
+	}
+
 	if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) {
 		/* in sequence */
 		msk->bytes_received += copy_len;
@@ -646,7 +691,9 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
 		if (offset < skb->len) {
 			size_t len = skb->len - offset;
 
-			ret = __mptcp_move_skb(msk, ssk, skb, offset, len) || ret;
+			mptcp_init_skb(ssk, skb, offset, len);
+			skb_orphan(skb);
+			ret = __mptcp_move_skb(sk, skb) || ret;
 			seq += len;
 
 			if (unlikely(map_remaining < len)) {
@@ -767,12 +814,8 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
 
 	moved = __mptcp_move_skbs_from_subflow(msk, ssk);
 	__mptcp_ofo_queue(msk);
-	if (unlikely(ssk->sk_err)) {
-		if (!sock_owned_by_user(sk))
-			__mptcp_error_report(sk);
-		else
-			__set_bit(MPTCP_ERROR_REPORT,  &msk->cb_flags);
-	}
+	if (unlikely(ssk->sk_err))
+		__mptcp_subflow_error_report(sk, ssk);
 
 	/* If the moves have caught up with the DATA_FIN sequence number
 	 * it's time to ack the DATA_FIN and change socket state, but
@@ -784,18 +827,10 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
 	return moved;
 }
 
-static void __mptcp_rcvbuf_update(struct sock *sk, struct sock *ssk)
-{
-	if (unlikely(ssk->sk_rcvbuf > sk->sk_rcvbuf))
-		WRITE_ONCE(sk->sk_rcvbuf, ssk->sk_rcvbuf);
-}
-
 static void __mptcp_data_ready(struct sock *sk, struct sock *ssk)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
-	__mptcp_rcvbuf_update(sk, ssk);
-
 	/* Wake-up the reader only for in-sequence data */
 	if (move_skbs_to_msk(msk, ssk) && mptcp_epollin_ready(sk))
 		sk->sk_data_ready(sk);
@@ -1943,12 +1978,13 @@ static int __mptcp_recvmsg_mskq(struct sock *sk,
 		}
 
 		if (!(flags & MSG_PEEK)) {
-			/* avoid the indirect call, we know the destructor is sock_wfree */
+			/* avoid the indirect call, we know the destructor is sock_rfree */
 			skb->destructor = NULL;
+			skb->sk = NULL;
 			atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
 			sk_mem_uncharge(sk, skb->truesize);
 			__skb_unlink(skb, &sk->sk_receive_queue);
-			__kfree_skb(skb);
+			skb_attempt_defer_free(skb);
 			msk->bytes_consumed += count;
 		}
 
@@ -2013,48 +2049,26 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
 	if (msk->rcvq_space.copied <= msk->rcvq_space.space)
 		goto new_measure;
 
-	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) &&
-	    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
-		u64 rcvwin, grow;
-		int rcvbuf;
-
-		rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss;
-
-		grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space);
-
-		do_div(grow, msk->rcvq_space.space);
-		rcvwin += (grow << 1);
-
-		rcvbuf = min_t(u64, mptcp_space_from_win(sk, rcvwin),
-			       READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[2]));
-
-		if (rcvbuf > sk->sk_rcvbuf) {
-			u32 window_clamp;
-
-			window_clamp = mptcp_win_from_space(sk, rcvbuf);
-			WRITE_ONCE(sk->sk_rcvbuf, rcvbuf);
+	msk->rcvq_space.space = msk->rcvq_space.copied;
+	if (mptcp_rcvbuf_grow(sk)) {
 
-			/* Make subflows follow along.  If we do not do this, we
-			 * get drops at subflow level if skbs can't be moved to
-			 * the mptcp rx queue fast enough (announced rcv_win can
-			 * exceed ssk->sk_rcvbuf).
-			 */
-			mptcp_for_each_subflow(msk, subflow) {
-				struct sock *ssk;
-				bool slow;
+		/* Make subflows follow along.  If we do not do this, we
+		 * get drops at subflow level if skbs can't be moved to
+		 * the mptcp rx queue fast enough (announced rcv_win can
+		 * exceed ssk->sk_rcvbuf).
+		 */
+		mptcp_for_each_subflow(msk, subflow) {
+			struct sock *ssk;
+			bool slow;
 
-				ssk = mptcp_subflow_tcp_sock(subflow);
-				slow = lock_sock_fast(ssk);
-				WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf);
-				WRITE_ONCE(tcp_sk(ssk)->window_clamp, window_clamp);
-				if (tcp_can_send_ack(ssk))
-					tcp_cleanup_rbuf(ssk, 1);
-				unlock_sock_fast(ssk, slow);
-			}
+			ssk = mptcp_subflow_tcp_sock(subflow);
+			slow = lock_sock_fast(ssk);
+			tcp_sk(ssk)->rcvq_space.space = msk->rcvq_space.copied;
+			tcp_rcvbuf_grow(ssk);
+			unlock_sock_fast(ssk, slow);
 		}
 	}
 
-	msk->rcvq_space.space = msk->rcvq_space.copied;
 new_measure:
 	msk->rcvq_space.copied = 0;
 	msk->rcvq_space.time = mstamp;
@@ -2083,11 +2097,6 @@ static bool __mptcp_move_skbs(struct sock *sk)
 	if (list_empty(&msk->conn_list))
 		return false;
 
-	/* verify we can move any data from the subflow, eventually updating */
-	if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK))
-		mptcp_for_each_subflow(msk, subflow)
-			__mptcp_rcvbuf_update(sk, subflow->tcp_sock);
-
 	subflow = list_first_entry(&msk->conn_list,
 				   struct mptcp_subflow_context, node);
 	for (;;) {
@@ -2205,14 +2214,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 				break;
 			}
 
-			if (sk->sk_shutdown & RCV_SHUTDOWN) {
-				/* race breaker: the shutdown could be after the
-				 * previous receive queue check
-				 */
-				if (__mptcp_move_skbs(sk))
-					continue;
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
 				break;
-			}
 
 			if (sk->sk_state == TCP_CLOSE) {
 				copied = -ENOTCONN;