@@ -569,15 +569,13 @@ static void mptcp_dss_corruption(struct mptcp_sock *msk, struct sock *ssk)
}
static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
- struct sock *ssk,
- unsigned int *bytes)
+ struct sock *ssk)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
struct sock *sk = (struct sock *)msk;
- unsigned int moved = 0;
bool more_data_avail;
struct tcp_sock *tp;
- bool done = false;
+ bool ret = false;
pr_debug("msk=%p ssk=%p\n", msk, ssk);
tp = tcp_sk(ssk);
@@ -587,20 +585,16 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
struct sk_buff *skb;
bool fin;
+ if (sk_rmem_alloc_get(sk) > sk->sk_rcvbuf)
+ break;
+
/* try to move as much data as available */
map_remaining = subflow->map_data_len -
mptcp_subflow_get_map_offset(subflow);
skb = skb_peek(&ssk->sk_receive_queue);
- if (!skb) {
- /* With racing move_skbs_to_msk() and __mptcp_move_skbs(),
- * a different CPU can have already processed the pending
- * data, stop here or we can enter an infinite loop
- */
- if (!moved)
- done = true;
+ if (unlikely(!skb))
break;
- }
if (__mptcp_check_fallback(msk)) {
/* Under fallback skbs have no MPTCP extension and TCP could
@@ -613,19 +607,13 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
offset = seq - TCP_SKB_CB(skb)->seq;
fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
- if (fin) {
- done = true;
+ if (fin)
seq++;
- }
if (offset < skb->len) {
size_t len = skb->len - offset;
- if (tp->urg_data)
- done = true;
-
- if (__mptcp_move_skb(msk, ssk, skb, offset, len))
- moved += len;
+ ret = __mptcp_move_skb(msk, ssk, skb, offset, len) || ret;
seq += len;
if (unlikely(map_remaining < len)) {
@@ -639,22 +627,16 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
}
sk_eat_skb(ssk, skb);
- done = true;
}
WRITE_ONCE(tp->copied_seq, seq);
more_data_avail = mptcp_subflow_data_available(ssk);
- if (sk_rmem_alloc_get(sk) > sk->sk_rcvbuf) {
- done = true;
- break;
- }
} while (more_data_avail);
- if (moved > 0)
+ if (ret)
msk->last_data_recv = tcp_jiffies32;
- *bytes += moved;
- return done;
+ return ret;
}
static bool __mptcp_ofo_queue(struct mptcp_sock *msk)
@@ -748,9 +730,9 @@ void __mptcp_error_report(struct sock *sk)
static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
{
struct sock *sk = (struct sock *)msk;
- unsigned int moved = 0;
+ bool moved;
- __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
+ moved = __mptcp_move_skbs_from_subflow(msk, ssk);
__mptcp_ofo_queue(msk);
if (unlikely(ssk->sk_err)) {
if (!sock_owned_by_user(sk))
@@ -766,7 +748,7 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk)
*/
if (mptcp_pending_data_fin(sk, NULL))
mptcp_schedule_work(sk);
- return moved > 0;
+ return moved;
}
static void __mptcp_rcvbuf_update(struct sock *sk, struct sock *ssk)
@@ -781,10 +763,6 @@ static void __mptcp_data_ready(struct sock *sk, struct sock *ssk)
__mptcp_rcvbuf_update(sk, ssk);
- /* over limit? can't append more skbs to msk, Also, no need to wake-up*/
- if (sk_rmem_alloc_get(sk) > sk->sk_rcvbuf)
- return;
-
/* 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);
@@ -884,20 +862,6 @@ bool mptcp_schedule_work(struct sock *sk)
return false;
}
-static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
-{
- struct mptcp_subflow_context *subflow;
-
- msk_owned_by_me(msk);
-
- mptcp_for_each_subflow(msk, subflow) {
- if (READ_ONCE(subflow->data_avail))
- return mptcp_subflow_tcp_sock(subflow);
- }
-
- return NULL;
-}
-
static bool mptcp_skb_can_collapse_to(u64 write_seq,
const struct sk_buff *skb,
const struct mptcp_ext *mpext)
@@ -2037,37 +2001,62 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
msk->rcvq_space.time = mstamp;
}
+static struct mptcp_subflow_context *
+__mptcp_first_ready_from(struct mptcp_sock *msk,
+ struct mptcp_subflow_context *subflow)
+{
+ struct mptcp_subflow_context *start_subflow = subflow;
+
+ while (!READ_ONCE(subflow->data_avail)) {
+ subflow = mptcp_next_subflow(msk, subflow);
+ if (subflow == start_subflow)
+ return NULL;
+ }
+ return subflow;
+}
+
static bool __mptcp_move_skbs(struct sock *sk)
{
struct mptcp_subflow_context *subflow;
struct mptcp_sock *msk = mptcp_sk(sk);
- unsigned int moved = 0;
- bool ret, done;
+ bool ret = false;
+
+ 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);
- if (sk_rmem_alloc_get(sk) > sk->sk_rcvbuf)
- return false;
-
- do {
- struct sock *ssk = mptcp_subflow_recv_lookup(msk);
+ subflow = list_first_entry(&msk->conn_list,
+ struct mptcp_subflow_context, node);
+ for (;;) {
+ struct sock *ssk;
bool slowpath;
- if (unlikely(!ssk))
+ /*
+ * As an optimization avoid traversing the subflows list
+ * and ev. acquiring the subflow socket lock before baling out
+ */
+ if (sk_rmem_alloc_get(sk) > sk->sk_rcvbuf)
break;
- slowpath = lock_sock_fast(ssk);
- done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved);
+ subflow = __mptcp_first_ready_from(msk, subflow);
+ if (!subflow)
+ break;
+ ssk = mptcp_subflow_tcp_sock(subflow);
+ slowpath = lock_sock_fast(ssk);
+ ret = __mptcp_move_skbs_from_subflow(msk, ssk) || ret;
if (unlikely(ssk->sk_err))
__mptcp_error_report(sk);
unlock_sock_fast(ssk, slowpath);
- } while (!done);
- ret = moved > 0 || __mptcp_ofo_queue(msk);
+ subflow = mptcp_next_subflow(msk, subflow);
+ }
+
+ __mptcp_ofo_queue(msk);
if (ret)
mptcp_check_data_fin((struct sock *)msk);
return ret;
@@ -354,6 +354,8 @@ struct mptcp_sock {
list_for_each_entry(__subflow, &((__msk)->conn_list), node)
#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp) \
list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
+#define mptcp_next_subflow(__msk, __subflow) \
+ list_next_entry_circular(__subflow, &((__msk)->conn_list), node)
extern struct genl_family mptcp_genl_family;