This patch adds a new member info_sent in struct mptcp_data_frag, save
info->sent in it, to support delay updating already_sent of dfrag until
all data are sent.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/protocol.c | 29 ++++++++++++++++++++++++-----
 net/mptcp/protocol.h |  1 +
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 262853d51e40..54863644e3ea 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1108,6 +1108,7 @@ mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag,
 	dfrag->data_seq = msk->write_seq;
 	dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag);
 	dfrag->offset = offset + sizeof(struct mptcp_data_frag);
+	dfrag->sent = 0;
 	dfrag->already_sent = 0;
 	dfrag->page = pfrag->page;
 
@@ -1493,11 +1494,11 @@ static void mptcp_update_post_push(struct mptcp_sock *msk,
 {
 	u64 snd_nxt_new = dfrag->data_seq;
 
-	dfrag->already_sent += sent;
+	dfrag->sent += sent;
 
 	msk->snd_burst -= sent;
 
-	snd_nxt_new += dfrag->already_sent;
+	snd_nxt_new += dfrag->sent;
 
 	/* snd_nxt_new can be smaller than snd_nxt in case mptcp
 	 * is recovering after a failover. In that event, this re-sends
@@ -1520,6 +1521,23 @@ static void mptcp_update_first_pending(struct sock *sk, struct mptcp_sendmsg_inf
 		WRITE_ONCE(msk->first_pending, mptcp_next_frag(sk, info->last_frag));
 }
 
+static void mptcp_update_dfrags(struct sock *sk, struct mptcp_sendmsg_info *info)
+{
+	struct mptcp_data_frag *dfrag = mptcp_send_head(sk);
+
+	if (!dfrag)
+		return;
+
+	do {
+		if (dfrag->sent) {
+			dfrag->already_sent = max(dfrag->already_sent, dfrag->sent);
+			dfrag->sent = 0;
+		}
+	} while ((dfrag = mptcp_next_frag(sk, dfrag)));
+
+	mptcp_update_first_pending(sk, info);
+}
+
 void mptcp_check_and_set_pending(struct sock *sk)
 {
 	if (mptcp_send_head(sk))
@@ -1543,6 +1561,7 @@ static int __subflow_push_pending(struct sock *sk, struct sock *ssk,
 		info->sent = dfrag->already_sent;
 		info->limit = dfrag->data_len;
 		len = dfrag->data_len - dfrag->already_sent;
+		dfrag->sent = info->sent;
 		while (len > 0) {
 			int ret = 0;
 
@@ -1617,7 +1636,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 				mptcp_subflow_set_scheduled(subflow, false);
 			}
 		}
-		mptcp_update_first_pending(sk, &info);
+		mptcp_update_dfrags(sk, &info);
 	}
 
 	/* at this point we held the socket lock for the last subflow we used */
@@ -1657,7 +1676,7 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool
 				break;
 			}
 			msk->last_snd = ssk;
-			mptcp_update_first_pending(sk, &info);
+			mptcp_update_dfrags(sk, &info);
 			continue;
 		}
 
@@ -1687,7 +1706,7 @@ static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool
 				mptcp_subflow_set_scheduled(subflow, false);
 			}
 		}
-		mptcp_update_first_pending(sk, &info);
+		mptcp_update_dfrags(sk, &info);
 	}
 
 out:
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index b2b5110a2aba..93932488f70b 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -241,6 +241,7 @@ struct mptcp_data_frag {
 	u16 data_len;
 	u16 offset;
 	u16 overhead;
+	u16 sent;
 	u16 already_sent;
 	struct page *page;
 };
-- 
2.35.3