X-Git-Url: http://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=blobdiff_plain;f=net%2Frds%2Fconnection.c;h=87df15b9f8e4b1072120f252520371f5e8c66146;hp=278f607ab603ff90d243472c1efc0a1735742558;hb=abf454398c2ebafc629ebb8b149f5a752c79e919;hpb=f64f9e719261a87818dd192a3a2352e5b20fbd0f

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 278f607..87df15b 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -32,11 +32,11 @@
  */
 #include <linux/kernel.h>
 #include <linux/list.h>
+#include <linux/slab.h>
 #include <net/inet_hashtables.h>
 
 #include "rds.h"
 #include "loop.h"
-#include "rdma.h"
 
 #define RDS_CONNECTION_HASH_BITS 12
 #define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
@@ -62,18 +62,6 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
 		var |= RDS_INFO_CONNECTION_FLAG_##suffix;	\
 } while (0)
 
-static inline int rds_conn_is_sending(struct rds_connection *conn)
-{
-	int ret = 0;
-
-	if (!mutex_trylock(&conn->c_send_lock))
-		ret = 1;
-	else
-		mutex_unlock(&conn->c_send_lock);
-
-	return ret;
-}
-
 static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
 					      __be32 laddr, __be32 faddr,
 					      struct rds_transport *trans)
@@ -147,7 +135,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 		goto out;
 
 	conn = kmem_cache_zalloc(rds_conn_slab, gfp);
-	if (conn == NULL) {
+	if (!conn) {
 		conn = ERR_PTR(-ENOMEM);
 		goto out;
 	}
@@ -158,7 +146,9 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 	spin_lock_init(&conn->c_lock);
 	conn->c_next_tx_seq = 1;
 
-	mutex_init(&conn->c_send_lock);
+	spin_lock_init(&conn->c_send_lock);
+	atomic_set(&conn->c_send_generation, 1);
+	atomic_set(&conn->c_senders, 0);
 	INIT_LIST_HEAD(&conn->c_send_queue);
 	INIT_LIST_HEAD(&conn->c_retrans);
 
@@ -262,6 +252,67 @@ struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
 }
 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
 
+void rds_conn_shutdown(struct rds_connection *conn)
+{
+	/* shut it down unless it's down already */
+	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
+		/*
+		 * Quiesce the connection mgmt handlers before we start tearing
+		 * things down. We don't hold the mutex for the entire
+		 * duration of the shutdown operation, else we may be
+		 * deadlocking with the CM handler. Instead, the CM event
+		 * handler is supposed to check for state DISCONNECTING
+		 */
+		mutex_lock(&conn->c_cm_lock);
+		if (!rds_conn_transition(conn, RDS_CONN_UP, RDS_CONN_DISCONNECTING)
+		 && !rds_conn_transition(conn, RDS_CONN_ERROR, RDS_CONN_DISCONNECTING)) {
+			rds_conn_error(conn, "shutdown called in state %d\n",
+					atomic_read(&conn->c_state));
+			mutex_unlock(&conn->c_cm_lock);
+			return;
+		}
+		mutex_unlock(&conn->c_cm_lock);
+
+		/* verify everybody's out of rds_send_xmit() */
+		spin_lock_irq(&conn->c_send_lock);
+		spin_unlock_irq(&conn->c_send_lock);
+
+		while(atomic_read(&conn->c_senders)) {
+			schedule_timeout(1);
+			spin_lock_irq(&conn->c_send_lock);
+			spin_unlock_irq(&conn->c_send_lock);
+		}
+
+		conn->c_trans->conn_shutdown(conn);
+		rds_conn_reset(conn);
+
+		if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) {
+			/* This can happen - eg when we're in the middle of tearing
+			 * down the connection, and someone unloads the rds module.
+			 * Quite reproduceable with loopback connections.
+			 * Mostly harmless.
+			 */
+			rds_conn_error(conn,
+				"%s: failed to transition to state DOWN, "
+				"current state is %d\n",
+				__func__,
+				atomic_read(&conn->c_state));
+			return;
+		}
+	}
+
+	/* Then reconnect if it's still live.
+	 * The passive side of an IB loopback connection is never added
+	 * to the conn hash, so we never trigger a reconnect on this
+	 * conn - the reconnect is always triggered by the active peer. */
+	cancel_delayed_work_sync(&conn->c_conn_w);
+	if (!hlist_unhashed(&conn->c_hash_node))
+		rds_queue_reconnect(conn);
+}
+
+/*
+ * Stop and free a connection.
+ */
 void rds_conn_destroy(struct rds_connection *conn)
 {
 	struct rds_message *rm, *rtmp;
@@ -270,7 +321,10 @@ void rds_conn_destroy(struct rds_connection *conn)
 		 "%pI4\n", conn, &conn->c_laddr,
 		 &conn->c_faddr);
 
+	/* Ensure conn will not be scheduled for reconnect */
+	spin_lock_irq(&rds_conn_lock);
 	hlist_del_init(&conn->c_hash_node);
+	spin_unlock_irq(&rds_conn_lock);
 
 	/* wait for the rds thread to shut it down */
 	atomic_set(&conn->c_state, RDS_CONN_ERROR);
@@ -423,7 +477,7 @@ static int rds_conn_info_visitor(struct rds_connection *conn,
 	cinfo->flags = 0;
 
 	rds_conn_info_set(cinfo->flags,
-			  rds_conn_is_sending(conn), SENDING);
+			  spin_is_locked(&conn->c_send_lock), SENDING);
 	/* XXX Future: return the state rather than these funky bits */
 	rds_conn_info_set(cinfo->flags,
 			  atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
@@ -448,7 +502,7 @@ int __init rds_conn_init(void)
 	rds_conn_slab = kmem_cache_create("rds_connection",
 					  sizeof(struct rds_connection),
 					  0, 0, NULL);
-	if (rds_conn_slab == NULL)
+	if (!rds_conn_slab)
 		return -ENOMEM;
 
 	rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);