Re: [PATCH V2 net-next 3/3] rds: tcp: cleanup if kmem_cache_alloc fails in rds_tcp_conn_alloc()

[Santosh Shilimkar]

On 12/22/2017 9:39 AM, Sowmini Varadhan wrote:

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 
---
v2: target net-next, not net


Acked-by: Santosh Shilimkar 

[PATCH V2 net-next 3/3] rds: tcp: cleanup if kmem_cache_alloc fails in rds_tcp_conn_alloc()

[Sowmini Varadhan]

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 
---
v2: target net-next, not net

 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(_tcp_conn_lock, flags);
+   if (!tc->t_tcp_node_detached)
+   list_del(>t_tcp_node);
+   spin_unlock_irqrestore(_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(>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(_tcp_conn_lock, flags);
-   if (!tc->t_tcp_node_detached)
-   list_del(>t_tcp_node);
-   spin_unlock_irqrestore(_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