RDS: TCP: Make rds_tcp_connection track the rds_conn_path

The struct rds_tcp_connection is the transport-specific private
data structure that tracks TCP information per rds_conn_path.
Modify this structure to have a back-pointer to the rds_conn_path
for which it is the ->cp_transport_data.

Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 48 insertions, 42 deletions

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 17c2f2591ac4..1b0c2a783b5e 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -253,9 +253,12 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 
                         for (i = 0; i < RDS_MPATH_WORKERS; i++) {
                                 cp = &conn->c_path[i];
-                                trans->conn_free(cp->cp_transport_data);
-                                if (!trans->t_mp_capable)
-                                        break;
+                                /* The ->conn_alloc invocation may have
+                                 * allocated resource for all paths, so all
+                                 * of them may have to be freed here.
+                                 */
+                                if (cp->cp_transport_data)
+                                        trans->conn_free(cp->cp_transport_data);
                         }
                         kmem_cache_free(rds_conn_slab, conn);
                         conn = found;
@@ -367,6 +370,9 @@ static void rds_conn_path_destroy(struct rds_conn_path *cp)
 {
         struct rds_message *rm, *rtmp;
 
+        if (!cp->cp_transport_data)
+                return;
+
         rds_conn_path_drop(cp);
         flush_work(&cp->cp_down_w);
 
@@ -398,6 +404,8 @@ static void rds_conn_path_destroy(struct rds_conn_path *cp)
 void rds_conn_destroy(struct rds_connection *conn)
 {
         unsigned long flags;
+        int i;
+        struct rds_conn_path *cp;
 
         rdsdebug("freeing conn %p for %pI4 -> "
                  "%pI4\n", conn, &conn->c_laddr,
@@ -410,18 +418,10 @@ void rds_conn_destroy(struct rds_connection *conn)
         synchronize_rcu();
 
         /* shut the connection down */
-        if (!conn->c_trans->t_mp_capable) {
-                rds_conn_path_destroy(&conn->c_path[0]);
-                BUG_ON(!list_empty(&conn->c_path[0].cp_retrans));
-        } else {
-                int i;
-                struct rds_conn_path *cp;
-
-                for (i = 0; i < RDS_MPATH_WORKERS; i++) {
-                        cp = &conn->c_path[i];
-                        rds_conn_path_destroy(cp);
-                        BUG_ON(!list_empty(&cp->cp_retrans));
-                }
+        for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+                cp = &conn->c_path[i];
+                rds_conn_path_destroy(cp);
+                BUG_ON(!list_empty(&cp->cp_retrans));
         }
 
         /*
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index c56fff28084f..c6b47f670990 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -221,7 +221,7 @@ void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
                 sock->sk->sk_data_ready = sock->sk->sk_user_data;
 
         tc->t_sock = sock;
-        tc->conn = conn;
+        tc->t_cpath = &conn->c_path[0];
         tc->t_orig_data_ready = sock->sk->sk_data_ready;
         tc->t_orig_write_space = sock->sk->sk_write_space;
         tc->t_orig_state_change = sock->sk->sk_state_change;
@@ -284,24 +284,29 @@ static int rds_tcp_laddr_check(struct net *net, __be32 addr)
 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 {
         struct rds_tcp_connection *tc;
+        int i;
 
-        tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
-        if (!tc)
-                return -ENOMEM;
+        for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+                tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
+                if (!tc)
+                        return -ENOMEM;
 
-        mutex_init(&tc->t_conn_lock);
-        tc->t_sock = NULL;
-        tc->t_tinc = NULL;
-        tc->t_tinc_hdr_rem = sizeof(struct rds_header);
-        tc->t_tinc_data_rem = 0;
+                mutex_init(&tc->t_conn_path_lock);
+                tc->t_sock = NULL;
+                tc->t_tinc = NULL;
+                tc->t_tinc_hdr_rem = sizeof(struct rds_header);
+                tc->t_tinc_data_rem = 0;
 
-        conn->c_transport_data = tc;
+                conn->c_path[i].cp_transport_data = tc;
+                tc->t_cpath = &conn->c_path[i];
 
-        spin_lock_irq(&rds_tcp_conn_lock);
-        list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
-        spin_unlock_irq(&rds_tcp_conn_lock);
+                spin_lock_irq(&rds_tcp_conn_lock);
+                list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
+                spin_unlock_irq(&rds_tcp_conn_lock);
+                rdsdebug("rds_conn_path [%d] tc %p\n", i,
+                         conn->c_path[i].cp_transport_data);
+        }
 
-        rdsdebug("alloced tc %p\n", conn->c_transport_data);
         return 0;
 }
 
@@ -330,7 +335,7 @@ static void rds_tcp_destroy_conns(void)
         spin_unlock_irq(&rds_tcp_conn_lock);
 
         list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
-                rds_conn_destroy(tc->conn);
+                rds_conn_destroy(tc->t_cpath->cp_conn);
 }
 
 static void rds_tcp_exit(void);
@@ -498,7 +503,7 @@ static void rds_tcp_kill_sock(struct net *net)
         flush_work(&rtn->rds_tcp_accept_w);
         spin_lock_irq(&rds_tcp_conn_lock);
         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
-                struct net *c_net = read_pnet(&tc->conn->c_net);
+                struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
 
                 if (net != c_net || !tc->t_sock)
                         continue;
@@ -509,7 +514,7 @@ static void rds_tcp_kill_sock(struct net *net)
                 sk = tc->t_sock->sk;
                 sk->sk_prot->disconnect(sk, 0);
                 tcp_done(sk);
-                rds_conn_destroy(tc->conn);
+                rds_conn_destroy(tc->t_cpath->cp_conn);
         }
 }
 
@@ -547,12 +552,13 @@ static void rds_tcp_sysctl_reset(struct net *net)
 
         spin_lock_irq(&rds_tcp_conn_lock);
         list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
-                struct net *c_net = read_pnet(&tc->conn->c_net);
+                struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
 
                 if (net != c_net || !tc->t_sock)
                         continue;
 
-                rds_conn_drop(tc->conn); /* reconnect with new parameters */
+                /* reconnect with new parameters */
+                rds_conn_path_drop(tc->t_cpath);
         }
         spin_unlock_irq(&rds_tcp_conn_lock);
 }
diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 728abe22c9a3..e1ff16908c5e 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -11,11 +11,11 @@ struct rds_tcp_incoming {
 struct rds_tcp_connection {
 
         struct list_head        t_tcp_node;
-        struct rds_connection   *conn;
-        /* t_conn_lock synchronizes the connection establishment between
+        struct rds_conn_path    *t_cpath;
+        /* t_conn_path_lock synchronizes the connection establishment between
          * rds_tcp_accept_one and rds_tcp_conn_connect
          */
-        struct mutex            t_conn_lock;
+        struct mutex            t_conn_path_lock;
         struct socket           *t_sock;
         void                    *t_orig_write_space;
         void                    *t_orig_data_ready;
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index aa65c1631c4b..146692c8afac 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -82,10 +82,10 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
         int ret;
         struct rds_tcp_connection *tc = conn->c_transport_data;
 
-        mutex_lock(&tc->t_conn_lock);
+        mutex_lock(&tc->t_conn_path_lock);
 
         if (rds_conn_up(conn)) {
-                mutex_unlock(&tc->t_conn_lock);
+                mutex_unlock(&tc->t_conn_path_lock);
                 return 0;
         }
         ret = sock_create_kern(rds_conn_net(conn), PF_INET,
@@ -129,7 +129,7 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
         }
 
 out:
-        mutex_unlock(&tc->t_conn_lock);
+        mutex_unlock(&tc->t_conn_path_lock);
         if (sock)
                 sock_release(sock);
         return ret;
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index f9cc945a77b3..d8933469ab13 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -121,7 +121,7 @@ int rds_tcp_accept_one(struct socket *sock)
          */
         rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
         rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
-        mutex_lock(&rs_tcp->t_conn_lock);
+        mutex_lock(&rs_tcp->t_conn_path_lock);
         conn_state = rds_conn_state(conn);
         if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_UP)
                 goto rst_nsk;
@@ -156,7 +156,7 @@ rst_nsk:
         ret = 0;
 out:
         if (rs_tcp)
-                mutex_unlock(&rs_tcp->t_conn_lock);
+                mutex_unlock(&rs_tcp->t_conn_path_lock);
         if (new_sock)
                 sock_release(new_sock);
         return ret;