RE: [Bluez-devel] Rfcomm Use Count

Marcel Holtmann
2004-09-21T20:32:24Z

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Hi Daryl,

> > for the L2CAP part the attached patch may fixes the problem
> > and let the
> > module reference count decrease after the disconnect. The
> > patch is only
> > compile tested. May you wanna give it a chance and run your
> > L2CAP tests
> > again.
>
> I gave it a try and it works fine as far as I can tell. I had to apply the
> patch manually though (I'm assuming this is because you're working with a
> 2.6 kernel and I'm not).

I will fix 2.6 first, before I will backport it to 2.4.

> I don't see the use count incrementing badly any more, and the listening
> socket will continue to accept connections after the number of
> connects/disconnects have exceeded the the accept queue.

This sounds great and hopefully this patch has no negative side effects
on normal listen/accept calls and outgoing connections.

> Does this give you any ideas for rfcomm?

Attached is the full patch that should also fix the RFCOMM part. This is
again only compile tested, because I had no time to setup a test system.
The L2CAP solution looks very sane to me, but I am not sure about the
RFCOMM part and we may will have a locking problem. This really needs
intensive testing.

Regards

Marcel

[-- Attachment #2: patch --]
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===== include/net/bluetooth/bluetooth.h 1.18 vs edited =====
--- 1.18/include/net/bluetooth/bluetooth.h 2004-07-04 17:27:14 +02:00
+++ edited/include/net/bluetooth/bluetooth.h 2004-09-21 01:26:06 +02:00
@@ -133,6 +133,7 @@
int bt_sock_wait_state(struct sock *sk, int state, unsigned long timeo);

void bt_accept_enqueue(struct sock *parent, struct sock *sk);
+void bt_accept_unlink(struct sock *sk);
struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock);

/* Skb helpers */
===== net/bluetooth/af_bluetooth.c 1.36 vs edited =====
--- 1.36/net/bluetooth/af_bluetooth.c 2004-07-13 15:39:15 +02:00
+++ edited/net/bluetooth/af_bluetooth.c 2004-09-21 01:26:17 +02:00
@@ -165,7 +165,7 @@
}
EXPORT_SYMBOL(bt_accept_enqueue);

-static void bt_accept_unlink(struct sock *sk)
+void bt_accept_unlink(struct sock *sk)
{
BT_DBG("sk %p state %d", sk, sk->sk_state);

@@ -174,6 +174,7 @@
bt_sk(sk)->parent = NULL;
sock_put(sk);
}
+EXPORT_SYMBOL(bt_accept_unlink);

struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
{
===== net/bluetooth/l2cap.c 1.44 vs edited =====
--- 1.44/net/bluetooth/l2cap.c 2004-09-04 12:51:17 +02:00
+++ edited/net/bluetooth/l2cap.c 2004-09-21 01:23:41 +02:00
@@ -1005,9 +1005,10 @@
if (err)
sk->sk_err = err;

- if (parent)
+ if (parent) {
+ bt_accept_unlink(sk);
parent->sk_data_ready(parent, 0);
- else
+ } else
sk->sk_state_change(sk);
}

===== net/bluetooth/rfcomm/sock.c 1.29 vs edited =====
--- 1.29/net/bluetooth/rfcomm/sock.c 2004-06-04 02:41:47 +02:00
+++ edited/net/bluetooth/rfcomm/sock.c 2004-09-21 02:09:47 +02:00
@@ -104,8 +104,11 @@
if (d->state == BT_CONNECTED)
rfcomm_session_getaddr(d->session, &bt_sk(sk)->src, NULL);
sk->sk_state_change(sk);
- } else
+ } else {
+ if (d->state == BT_CLOSED)
+ bt_accept_unlink(sk);
parent->sk_data_ready(parent, 0);
+ }

bh_unlock_sock(sk);
}