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-rw-r--r--net/rds/rds.h2
-rw-r--r--net/rds/send.c1
-rw-r--r--net/rds/tcp.c78
-rw-r--r--net/rds/tcp.h1
-rw-r--r--net/rds/tcp_connect.c2
-rw-r--r--net/rds/tcp_listen.c20
-rw-r--r--net/rds/threads.c10
7 files changed, 95 insertions, 19 deletions
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 80256b08eac0..387df5f32e49 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -74,6 +74,7 @@ enum {
RDS_CONN_CONNECTING,
RDS_CONN_DISCONNECTING,
RDS_CONN_UP,
+ RDS_CONN_RESETTING,
RDS_CONN_ERROR,
};
@@ -813,6 +814,7 @@ void rds_connect_worker(struct work_struct *);
void rds_shutdown_worker(struct work_struct *);
void rds_send_worker(struct work_struct *);
void rds_recv_worker(struct work_struct *);
+void rds_connect_path_complete(struct rds_connection *conn, int curr);
void rds_connect_complete(struct rds_connection *conn);
/* transport.c */
diff --git a/net/rds/send.c b/net/rds/send.c
index c9cdb358ea88..b1962f8e30f7 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -99,6 +99,7 @@ void rds_send_reset(struct rds_connection *conn)
list_splice_init(&conn->c_retrans, &conn->c_send_queue);
spin_unlock_irqrestore(&conn->c_lock, flags);
}
+EXPORT_SYMBOL_GPL(rds_send_reset);
static int acquire_in_xmit(struct rds_connection *conn)
{
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 86187dad1440..74ee126a6fe6 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -126,9 +126,81 @@ void rds_tcp_restore_callbacks(struct socket *sock,
}
/*
- * This is the only path that sets tc->t_sock. Send and receive trust that
- * it is set. The RDS_CONN_UP bit protects those paths from being
- * called while it isn't set.
+ * rds_tcp_reset_callbacks() switches the to the new sock and
+ * returns the existing tc->t_sock.
+ *
+ * The only functions that set tc->t_sock are rds_tcp_set_callbacks
+ * and rds_tcp_reset_callbacks. Send and receive trust that
+ * it is set. The absence of RDS_CONN_UP bit protects those paths
+ * from being called while it isn't set.
+ */
+void rds_tcp_reset_callbacks(struct socket *sock,
+ struct rds_connection *conn)
+{
+ struct rds_tcp_connection *tc = conn->c_transport_data;
+ struct socket *osock = tc->t_sock;
+
+ if (!osock)
+ goto newsock;
+
+ /* Need to resolve a duelling SYN between peers.
+ * We have an outstanding SYN to this peer, which may
+ * potentially have transitioned to the RDS_CONN_UP state,
+ * so we must quiesce any send threads before resetting
+ * c_transport_data. We quiesce these threads by setting
+ * c_state to something other than RDS_CONN_UP, and then
+ * waiting for any existing threads in rds_send_xmit to
+ * complete release_in_xmit(). (Subsequent threads entering
+ * rds_send_xmit() will bail on !rds_conn_up().
+ *
+ * However an incoming syn-ack at this point would end up
+ * marking the conn as RDS_CONN_UP, and would again permit
+ * rds_send_xmi() threads through, so ideally we would
+ * synchronize on RDS_CONN_UP after lock_sock(), but cannot
+ * do that: waiting on !RDS_IN_XMIT after lock_sock() may
+ * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
+ * would not get set. As a result, we set c_state to
+ * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
+ * cannot mark rds_conn_path_up() in the window before lock_sock()
+ */
+ atomic_set(&conn->c_state, RDS_CONN_RESETTING);
+ wait_event(conn->c_waitq, !test_bit(RDS_IN_XMIT, &conn->c_flags));
+ lock_sock(osock->sk);
+ /* reset receive side state for rds_tcp_data_recv() for osock */
+ if (tc->t_tinc) {
+ rds_inc_put(&tc->t_tinc->ti_inc);
+ tc->t_tinc = NULL;
+ }
+ tc->t_tinc_hdr_rem = sizeof(struct rds_header);
+ tc->t_tinc_data_rem = 0;
+ tc->t_sock = NULL;
+
+ write_lock_bh(&osock->sk->sk_callback_lock);
+
+ osock->sk->sk_user_data = NULL;
+ osock->sk->sk_data_ready = tc->t_orig_data_ready;
+ osock->sk->sk_write_space = tc->t_orig_write_space;
+ osock->sk->sk_state_change = tc->t_orig_state_change;
+ write_unlock_bh(&osock->sk->sk_callback_lock);
+ release_sock(osock->sk);
+ sock_release(osock);
+newsock:
+ rds_send_reset(conn);
+ lock_sock(sock->sk);
+ write_lock_bh(&sock->sk->sk_callback_lock);
+ tc->t_sock = sock;
+ sock->sk->sk_user_data = conn;
+ sock->sk->sk_data_ready = rds_tcp_data_ready;
+ sock->sk->sk_write_space = rds_tcp_write_space;
+ sock->sk->sk_state_change = rds_tcp_state_change;
+
+ write_unlock_bh(&sock->sk->sk_callback_lock);
+ release_sock(sock->sk);
+}
+
+/* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
+ * above rds_tcp_reset_callbacks for notes about synchronization
+ * with data path
*/
void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
{
diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 41c228300525..ec0602b0dc24 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -50,6 +50,7 @@ struct rds_tcp_statistics {
void rds_tcp_tune(struct socket *sock);
void rds_tcp_nonagle(struct socket *sock);
void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn);
+void rds_tcp_reset_callbacks(struct socket *sock, struct rds_connection *conn);
void rds_tcp_restore_callbacks(struct socket *sock,
struct rds_tcp_connection *tc);
u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc);
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index fb82e0a0bf89..fba13d0305fb 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -60,7 +60,7 @@ void rds_tcp_state_change(struct sock *sk)
case TCP_SYN_RECV:
break;
case TCP_ESTABLISHED:
- rds_connect_complete(conn);
+ rds_connect_path_complete(conn, RDS_CONN_CONNECTING);
break;
case TCP_CLOSE_WAIT:
case TCP_CLOSE:
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 4bf4befe5066..686b1d03a558 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -78,7 +78,6 @@ int rds_tcp_accept_one(struct socket *sock)
struct inet_sock *inet;
struct rds_tcp_connection *rs_tcp = NULL;
int conn_state;
- struct sock *nsk;
if (!sock) /* module unload or netns delete in progress */
return -ENETUNREACH;
@@ -136,26 +135,21 @@ int rds_tcp_accept_one(struct socket *sock)
!conn->c_outgoing) {
goto rst_nsk;
} else {
- atomic_set(&conn->c_state, RDS_CONN_CONNECTING);
- wait_event(conn->c_waitq,
- !test_bit(RDS_IN_XMIT, &conn->c_flags));
- rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
+ rds_tcp_reset_callbacks(new_sock, conn);
conn->c_outgoing = 0;
+ /* rds_connect_path_complete() marks RDS_CONN_UP */
+ rds_connect_path_complete(conn, RDS_CONN_DISCONNECTING);
}
+ } else {
+ rds_tcp_set_callbacks(new_sock, conn);
+ rds_connect_path_complete(conn, RDS_CONN_CONNECTING);
}
- rds_tcp_set_callbacks(new_sock, conn);
- rds_connect_complete(conn); /* marks RDS_CONN_UP */
new_sock = NULL;
ret = 0;
goto out;
rst_nsk:
/* reset the newly returned accept sock and bail */
- nsk = new_sock->sk;
- rds_tcp_stats_inc(s_tcp_listen_closed_stale);
- nsk->sk_user_data = NULL;
- nsk->sk_prot->disconnect(nsk, 0);
- tcp_done(nsk);
- new_sock = NULL;
+ kernel_sock_shutdown(new_sock, SHUT_RDWR);
ret = 0;
out:
if (rs_tcp)
diff --git a/net/rds/threads.c b/net/rds/threads.c
index 454aa6d23327..4a323045719b 100644
--- a/net/rds/threads.c
+++ b/net/rds/threads.c
@@ -71,9 +71,9 @@
struct workqueue_struct *rds_wq;
EXPORT_SYMBOL_GPL(rds_wq);
-void rds_connect_complete(struct rds_connection *conn)
+void rds_connect_path_complete(struct rds_connection *conn, int curr)
{
- if (!rds_conn_transition(conn, RDS_CONN_CONNECTING, RDS_CONN_UP)) {
+ if (!rds_conn_transition(conn, curr, RDS_CONN_UP)) {
printk(KERN_WARNING "%s: Cannot transition to state UP, "
"current state is %d\n",
__func__,
@@ -90,6 +90,12 @@ void rds_connect_complete(struct rds_connection *conn)
queue_delayed_work(rds_wq, &conn->c_send_w, 0);
queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
}
+EXPORT_SYMBOL_GPL(rds_connect_path_complete);
+
+void rds_connect_complete(struct rds_connection *conn)
+{
+ rds_connect_path_complete(conn, RDS_CONN_CONNECTING);
+}
EXPORT_SYMBOL_GPL(rds_connect_complete);
/*
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 06:06:59 +0000