mptcp: implement memory accounting for mptcp rtx queue

Charge the data on the rtx queue to the master MPTCP socket, too.
Such memory in uncharged when the data is acked/dequeued.

Also account mptcp sockets inuse via a protocol specific pcpu
counter.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 002c6311357a53266b77aae70137ed4bd64a8464..19038c260f1f1c6df85829dea24e7c3913bff47d 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -37,6 +37,8 @@ struct mptcp_skb_cb {
 
 #define MPTCP_SKB_CB(__skb)    ((struct mptcp_skb_cb *)&((__skb)->cb[0]))
 
+static struct percpu_counter mptcp_sockets_allocated;
+
 /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
  * completed yet or has failed, return the subflow socket.
  * Otherwise return NULL.
@@ -333,9 +335,17 @@ static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
                df->data_seq + df->data_len == msk->write_seq;
 }
 
-static void dfrag_clear(struct mptcp_data_frag *dfrag)
+static void dfrag_uncharge(struct sock *sk, int len)
+{
+       sk_mem_uncharge(sk, len);
+}
+
+static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag)
 {
+       int len = dfrag->data_len + dfrag->overhead;
+
        list_del(&dfrag->list);
+       dfrag_uncharge(sk, len);
        put_page(dfrag->page);
 }
 
@@ -344,12 +354,18 @@ static void mptcp_clean_una(struct sock *sk)
        struct mptcp_sock *msk = mptcp_sk(sk);
        struct mptcp_data_frag *dtmp, *dfrag;
        u64 snd_una = atomic64_read(&msk->snd_una);
+       bool cleaned = false;
 
        list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) {
                if (after64(dfrag->data_seq + dfrag->data_len, snd_una))
                        break;
 
-               dfrag_clear(dfrag);
+               dfrag_clear(sk, dfrag);
+               cleaned = true;
+       }
+
+       if (cleaned) {
+               sk_mem_reclaim_partial(sk);
        }
 }
 
@@ -461,6 +477,9 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
        if (!psize)
                return -EINVAL;
 
+       if (!sk_wmem_schedule(sk, psize + dfrag->overhead))
+               return -ENOMEM;
+
        /* tell the TCP stack to delay the push so that we can safely
         * access the skb after the sendpages call
         */
@@ -482,6 +501,11 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
                list_add_tail(&dfrag->list, &msk->rtx_queue);
        }
 
+       /* charge data on mptcp rtx queue to the master socket
+        * Note: we charge such data both to sk and ssk
+        */
+       sk->sk_forward_alloc -= frag_truesize;
+
        /* if the tail skb extension is still the cached one, collapsing
         * really happened. Note: we can't check for 'same skb' as the sk_buff
         * hdr on tail can be transmitted, freed and re-allocated by the
@@ -933,6 +957,8 @@ static int mptcp_init_sock(struct sock *sk)
        if (ret)
                return ret;
 
+       sk_sockets_allocated_inc(sk);
+
        if (!mptcp_is_enabled(sock_net(sk)))
                return -ENOPROTOOPT;
 
@@ -947,7 +973,7 @@ static void __mptcp_clear_xmit(struct sock *sk)
        sk_stop_timer(sk, &msk->sk.icsk_retransmit_timer);
 
        list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list)
-               dfrag_clear(dfrag);
+               dfrag_clear(sk, dfrag);
 }
 
 static void mptcp_cancel_work(struct sock *sk)
@@ -1182,6 +1208,8 @@ static void mptcp_destroy(struct sock *sk)
 
        if (msk->cached_ext)
                __skb_ext_put(msk->cached_ext);
+
+       sk_sockets_allocated_dec(sk);
 }
 
 static int mptcp_setsockopt(struct sock *sk, int level, int optname,
@@ -1391,7 +1419,12 @@ static struct proto mptcp_prot = {
        .hash           = inet_hash,
        .unhash         = inet_unhash,
        .get_port       = mptcp_get_port,
+       .sockets_allocated      = &mptcp_sockets_allocated,
+       .memory_allocated       = &tcp_memory_allocated,
+       .memory_pressure        = &tcp_memory_pressure,
        .stream_memory_free     = mptcp_memory_free,
+       .sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_tcp_wmem),
+       .sysctl_mem     = sysctl_tcp_mem,
        .obj_size       = sizeof(struct mptcp_sock),
        .no_autobind    = true,
 };
@@ -1680,6 +1713,9 @@ void mptcp_proto_init(void)
 {
        mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;
 
+       if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL))
+               panic("Failed to allocate MPTCP pcpu counter\n");
+
        mptcp_subflow_init();
        mptcp_pm_init();