rxrpc: Unlock new call in rxrpc_new_incoming_call() rather than the caller
authorDavid Howells <dhowells@redhat.com>
Wed, 18 Dec 2019 16:38:49 +0000 (16:38 +0000)
committerDavid Howells <dhowells@redhat.com>
Fri, 20 Dec 2019 16:20:48 +0000 (16:20 +0000)
Move the unlock and the ping transmission for a new incoming call into
rxrpc_new_incoming_call() rather than doing it in the caller.  This makes
it clearer to see what's going on.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
cc: Ingo Molnar <mingo@redhat.com>
cc: Will Deacon <will@kernel.org>
cc: Davidlohr Bueso <dave@stgolabs.net>

net/rxrpc/call_accept.c
net/rxrpc/input.c

index 135bf5cd8dd51be0414ebb89975331d3f47d7b4e..3685b1732f65fba7325cf1fb84fe0330c0360243 100644 (file)
@@ -239,6 +239,22 @@ void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
        kfree(b);
 }
 
+/*
+ * Ping the other end to fill our RTT cache and to retrieve the rwind
+ * and MTU parameters.
+ */
+static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb)
+{
+       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+       ktime_t now = skb->tstamp;
+
+       if (call->peer->rtt_usage < 3 ||
+           ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
+               rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
+                                 true, true,
+                                 rxrpc_propose_ack_ping_for_params);
+}
+
 /*
  * Allocate a new incoming call from the prealloc pool, along with a connection
  * and a peer as necessary.
@@ -346,9 +362,7 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
                                  sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
                skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
                skb->priority = RX_INVALID_OPERATION;
-               _leave(" = NULL [close]");
-               call = NULL;
-               goto out;
+               goto no_call;
        }
 
        /* The peer, connection and call may all have sprung into existence due
@@ -361,9 +375,7 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
        call = rxrpc_alloc_incoming_call(rx, local, peer, conn, skb);
        if (!call) {
                skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
-               _leave(" = NULL [busy]");
-               call = NULL;
-               goto out;
+               goto no_call;
        }
 
        trace_rxrpc_receive(call, rxrpc_receive_incoming,
@@ -432,10 +444,18 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
         */
        rxrpc_put_call(call, rxrpc_call_put);
 
-       _leave(" = %p{%d}", call, call->debug_id);
-out:
        spin_unlock(&rx->incoming_lock);
+
+       rxrpc_send_ping(call, skb);
+       mutex_unlock(&call->user_mutex);
+
+       _leave(" = %p{%d}", call, call->debug_id);
        return call;
+
+no_call:
+       spin_unlock(&rx->incoming_lock);
+       _leave(" = NULL [%u]", skb->mark);
+       return NULL;
 }
 
 /*
index 157be1ff8697be438a7ee6636e37671169fff3df..86bd133b4fa0a858595eb2e259d99b31e58c47e7 100644 (file)
@@ -192,22 +192,6 @@ send_extra_data:
        goto out_no_clear_ca;
 }
 
-/*
- * Ping the other end to fill our RTT cache and to retrieve the rwind
- * and MTU parameters.
- */
-static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb)
-{
-       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-       ktime_t now = skb->tstamp;
-
-       if (call->peer->rtt_usage < 3 ||
-           ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
-               rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
-                                 true, true,
-                                 rxrpc_propose_ack_ping_for_params);
-}
-
 /*
  * Apply a hard ACK by advancing the Tx window.
  */
@@ -1396,8 +1380,6 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
                call = rxrpc_new_incoming_call(local, rx, skb);
                if (!call)
                        goto reject_packet;
-               rxrpc_send_ping(call, skb);
-               mutex_unlock(&call->user_mutex);
        }
 
        /* Process a call packet; this either discards or passes on the ref