Merge tag 'rxrpc-rewrite-20160824-1' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: More fixes

Here are a couple of fix patches:

 (1) Fix the conn-based retransmission patch posted yesterday.  This breaks
     if it actually has to retransmit.  However, it seems the likelihood of
     this happening is really low, despite the server I'm testing against
     being located >3000 miles away, and sometime of the time it's handled
     in the call background processor before we manage to disconnect the
     call - hence why I didn't spot it.

 (2) /proc/net/rxrpc_calls can cause a crash it accessed whilst a call is
     being torn down.  The window of opportunity is pretty small, however,
     as calls don't stay in this state for long.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 28 insertions, 10 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 7296039c537a..5292bf0bce52 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -407,6 +407,7 @@ enum rxrpc_call_state {
 struct rxrpc_call {
         struct rcu_head         rcu;
         struct rxrpc_connection *conn;          /* connection carrying call */
+        struct rxrpc_peer       *peer;          /* Peer record for remote address */
         struct rxrpc_sock       *socket;        /* socket responsible */
         struct timer_list       lifetimer;      /* lifetime remaining on call */
         struct timer_list       deadspan;       /* reap timer for re-ACK'ing, etc  */
@@ -717,9 +718,10 @@ struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *,
                                      struct sockaddr_rxrpc *, gfp_t);
 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t);
 
-static inline void rxrpc_get_peer(struct rxrpc_peer *peer)
+static inline struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
 {
         atomic_inc(&peer->usage);
+        return peer;
 }
 
 static inline
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 4af01805bfc7..f23432591a0f 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -315,6 +315,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
         candidate->socket       = rx;
         candidate->conn         = conn;
+        candidate->peer         = conn->params.peer;
         candidate->cid          = sp->hdr.cid;
         candidate->call_id      = sp->hdr.callNumber;
         candidate->rx_data_post = 0;
@@ -384,6 +385,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
         rcu_assign_pointer(conn->channels[chan].call, call);
         sock_hold(&rx->sk);
         rxrpc_get_connection(conn);
+        rxrpc_get_peer(call->peer);
         spin_unlock(&conn->channel_lock);
 
         spin_lock(&conn->params.peer->lock);
@@ -610,6 +612,7 @@ static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 
         rxrpc_purge_queue(&call->rx_queue);
+        rxrpc_put_peer(call->peer);
         kmem_cache_free(rxrpc_call_jar, call);
 }
 
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index fc32cc67c2de..2d43c99e5360 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -280,6 +280,7 @@ attached:
 found_channel:
         _debug("found chan");
         call->conn      = conn;
+        call->peer      = rxrpc_get_peer(conn->params.peer);
         call->cid       = conn->proto.cid | chan;
         call->call_id   = ++conn->channels[chan].call_counter;
         conn->channels[chan].call_id = call->call_id;
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index c1c6b7f305d1..6296374df840 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -42,6 +42,7 @@ static void rxrpc_conn_retransmit(struct rxrpc_connection *conn,
                         } abort;
                         struct {
                                 struct rxrpc_ackpacket ack;
+                                u8 padding[3];
                                 struct rxrpc_ackinfo info;
                         };
                 };
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 66cdeb56f44f..5e683dd21ab9 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -732,7 +732,7 @@ void rxrpc_data_ready(struct sock *sk)
                         /* For the previous service call, if completed
                          * successfully, we discard all further packets.
                          */
-                        if (rxrpc_conn_is_service(call->conn) &&
+                        if (rxrpc_conn_is_service(conn) &&
                             (chan->last_type == RXRPC_PACKET_TYPE_ACK ||
                              sp->hdr.type == RXRPC_PACKET_TYPE_ABORT))
                                 goto discard_unlock;
diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c
index 31b7f36a39cb..53872631a66d 100644
--- a/net/rxrpc/proc.c
+++ b/net/rxrpc/proc.c
@@ -46,7 +46,9 @@ static void rxrpc_call_seq_stop(struct seq_file *seq, void *v)
 
 static int rxrpc_call_seq_show(struct seq_file *seq, void *v)
 {
-        struct rxrpc_connection *conn;
+        struct rxrpc_local *local;
+        struct rxrpc_sock *rx;
+        struct rxrpc_peer *peer;
         struct rxrpc_call *call;
         char lbuff[4 + 4 + 4 + 4 + 5 + 1], rbuff[4 + 4 + 4 + 4 + 5 + 1];
 
@@ -60,15 +62,24 @@ static int rxrpc_call_seq_show(struct seq_file *seq, void *v)
 
         call = list_entry(v, struct rxrpc_call, link);
 
-        sprintf(lbuff, "%pI4:%u",
-                &call->socket->local->srx.transport.sin.sin_addr,
-                ntohs(call->socket->local->srx.transport.sin.sin_port));
+        rx = READ_ONCE(call->socket);
+        if (rx) {
+                local = READ_ONCE(rx->local);
+                if (local)
+                        sprintf(lbuff, "%pI4:%u",
+                                &local->srx.transport.sin.sin_addr,
+                                ntohs(local->srx.transport.sin.sin_port));
+                else
+                        strcpy(lbuff, "no_local");
+        } else {
+                strcpy(lbuff, "no_socket");
+        }
 
-        conn = call->conn;
-        if (conn)
+        peer = call->peer;
+        if (peer)
                 sprintf(rbuff, "%pI4:%u",
-                        &conn->params.peer->srx.transport.sin.sin_addr,
-                        ntohs(conn->params.peer->srx.transport.sin.sin_port));
+                        &peer->srx.transport.sin.sin_addr,
+                        ntohs(peer->srx.transport.sin.sin_port));
         else
                 strcpy(rbuff, "no_connection");