netdev - [PATCH net 3/3] rds: tcp: cleanup if kmem_cache_alloc fails in rds_tcp_conn

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Date:   Fri, 22 Dec 2017 08:14:48 -0800
From:   Sowmini Varadhan <sowmini.varadhan@...cle.com>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, rds-devel@....oracle.com,
        sowmini.varadhan@...cle.com, santosh.shilimkar@...cle.com
Subject: [PATCH net 3/3] rds: tcp: cleanup if kmem_cache_alloc fails in rds_tcp_conn_alloc()

If kmem_cache_alloc() fails in the middle of the for() loop,
cleanup anything that might have been allocated so far.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@...cle.com>
---
 net/rds/tcp.c |   46 ++++++++++++++++++++++++++--------------------
 1 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index a61a498..2e554ef 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -270,16 +270,33 @@ static int rds_tcp_laddr_check(struct net *net, __be32 addr)
 	return -EADDRNOTAVAIL;
 }
 
+static void rds_tcp_conn_free(void *arg)
+{
+	struct rds_tcp_connection *tc = arg;
+	unsigned long flags;
+
+	rdsdebug("freeing tc %p\n", tc);
+
+	spin_lock_irqsave(&rds_tcp_conn_lock, flags);
+	if (!tc->t_tcp_node_detached)
+		list_del(&tc->t_tcp_node);
+	spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
+
+	kmem_cache_free(rds_tcp_conn_slab, tc);
+}
+
 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 {
 	struct rds_tcp_connection *tc;
-	int i;
+	int i, j;
+	int ret = 0;
 
 	for (i = 0; i < RDS_MPATH_WORKERS; i++) {
 		tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
-		if (!tc)
-			return -ENOMEM;
-
+		if (!tc) {
+			ret = -ENOMEM;
+			break;
+		}
 		mutex_init(&tc->t_conn_path_lock);
 		tc->t_sock = NULL;
 		tc->t_tinc = NULL;
@@ -296,22 +313,11 @@ static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 		rdsdebug("rds_conn_path [%d] tc %p\n", i,
 			 conn->c_path[i].cp_transport_data);
 	}
-
-	return 0;
-}
-
-static void rds_tcp_conn_free(void *arg)
-{
-	struct rds_tcp_connection *tc = arg;
-	unsigned long flags;
-	rdsdebug("freeing tc %p\n", tc);
-
-	spin_lock_irqsave(&rds_tcp_conn_lock, flags);
-	if (!tc->t_tcp_node_detached)
-		list_del(&tc->t_tcp_node);
-	spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
-
-	kmem_cache_free(rds_tcp_conn_slab, tc);
+	if (ret) {
+		for (j = 0; j < i; j++)
+			rds_tcp_conn_free(conn->c_path[j].cp_transport_data);
+	}
+	return ret;
 }
 
 static bool list_has_conn(struct list_head *list, struct rds_connection *conn)
-- 
1.7.1