caif: Bugfix debugfs directory name must be unique.

Race condition caused debugfs_create_dir() to fail due to duplicate
name. Use atomic counter to create unique directory name.

net_ratelimit() is introduced to limit debug printouts.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 7baae11..5cf9c73 100644 (file)
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -48,6 +48,7 @@ static struct dentry *debugfsdir;
 #ifdef CONFIG_DEBUG_FS
 struct debug_fs_counter {
        atomic_t caif_nr_socks;
+       atomic_t caif_sock_create;
        atomic_t num_connect_req;
        atomic_t num_connect_resp;
        atomic_t num_connect_fail_resp;
@@ -59,11 +60,11 @@ struct debug_fs_counter {
        atomic_t num_rx_flow_on;
 };
 static struct debug_fs_counter cnt;
-#define        dbfs_atomic_inc(v) atomic_inc(v)
-#define        dbfs_atomic_dec(v) atomic_dec(v)
+#define        dbfs_atomic_inc(v) atomic_inc_return(v)
+#define        dbfs_atomic_dec(v) atomic_dec_return(v)
 #else
-#define        dbfs_atomic_inc(v)
-#define        dbfs_atomic_dec(v)
+#define        dbfs_atomic_inc(v) 0
+#define        dbfs_atomic_dec(v) 0
 #endif
 
 struct caifsock {
@@ -155,9 +156,10 @@ static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
        if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
                (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
-               pr_debug("sending flow OFF (queue len = %d %d)\n",
-                       atomic_read(&cf_sk->sk.sk_rmem_alloc),
-                       sk_rcvbuf_lowwater(cf_sk));
+               if (net_ratelimit())
+                       pr_debug("sending flow OFF (queue len = %d %d)\n",
+                                       atomic_read(&cf_sk->sk.sk_rmem_alloc),
+                                       sk_rcvbuf_lowwater(cf_sk));
                set_rx_flow_off(cf_sk);
                dbfs_atomic_inc(&cnt.num_rx_flow_off);
                caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
@@ -168,7 +170,8 @@ static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
                return err;
        if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
                set_rx_flow_off(cf_sk);
-               pr_debug("sending flow OFF due to rmem_schedule\n");
+               if (net_ratelimit())
+                       pr_debug("sending flow OFF due to rmem_schedule\n");
                dbfs_atomic_inc(&cnt.num_rx_flow_off);
                caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
        }
@@ -838,7 +841,7 @@ static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
        sock->state = SS_CONNECTING;
        sk->sk_state = CAIF_CONNECTING;
 
-       /* Check priority value coming from socket */
+       /* Check priority value comming from socket */
        /* if priority value is out of range it will be ajusted */
        if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
                cf_sk->conn_req.priority = CAIF_PRIO_MAX;
@@ -942,6 +945,7 @@ static int caif_release(struct socket *sock)
 
        dbfs_atomic_inc(&cnt.num_disconnect);
 
+       WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
        if (cf_sk->debugfs_socket_dir != NULL)
                debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
 
@@ -1047,7 +1051,7 @@ static void caif_sock_destructor(struct sock *sk)
        caif_assert(sk_unhashed(sk));
        caif_assert(!sk->sk_socket);
        if (!sock_flag(sk, SOCK_DEAD)) {
-               pr_info("Attempt to release alive CAIF socket: %p\n", sk);
+               pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
                return;
        }
        sk_stream_kill_queues(&cf_sk->sk);
@@ -1058,6 +1062,7 @@ static void caif_sock_destructor(struct sock *sk)
 static int caif_create(struct net *net, struct socket *sock, int protocol,
                        int kern)
 {
+       int num;
        struct sock *sk = NULL;
        struct caifsock *cf_sk = NULL;
        static struct proto prot = {.name = "PF_CAIF",
@@ -1120,14 +1125,16 @@ static int caif_create(struct net *net, struct socket *sock, int protocol,
        cf_sk->conn_req.protocol = protocol;
        /* Increase the number of sockets created. */
        dbfs_atomic_inc(&cnt.caif_nr_socks);
+       num = dbfs_atomic_inc(&cnt.caif_sock_create);
 #ifdef CONFIG_DEBUG_FS
        if (!IS_ERR(debugfsdir)) {
+
                /* Fill in some information concerning the misc socket. */
-               snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
-                               atomic_read(&cnt.caif_nr_socks));
+               snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
 
                cf_sk->debugfs_socket_dir =
                        debugfs_create_dir(cf_sk->name, debugfsdir);
+
                debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
                                cf_sk->debugfs_socket_dir,
                                (u32 *) &cf_sk->sk.sk_state);
@@ -1171,6 +1178,9 @@ static int __init caif_sktinit_module(void)
                debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
                                debugfsdir,
                                (u32 *) &cnt.caif_nr_socks);
+               debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
+                               debugfsdir,
+                               (u32 *) &cnt.caif_sock_create);
                debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
                                debugfsdir,
                                (u32 *) &cnt.num_connect_req);