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| author | David Herrmann <dh.herrmann@gmail.com> | 2013-04-06 20:28:44 +0200 |
|---|---|---|
| committer | Gustavo Padovan <gustavo.padovan@collabora.co.uk> | 2013-04-17 03:02:10 -0300 |
| commit | 9c903e373c11f62d62bce1209f662ca92589a075 (patch) | |
| tree | 285f6ef70c1e869b7ebd86dcad2a4057ea61134e | |
| parent | 3764eaa922c78037ad9bed06be5c8b8a5c83b37d (diff) | |
| download | linux-9c903e373c11f62d62bce1209f662ca92589a075.tar.bz2 | |
Bluetooth: l2cap: introduce l2cap_conn ref-counting
If we want to use l2cap_conn outside of l2cap_core.c, we need refcounting
for these objects. Otherwise, we cannot synchronize l2cap locks with
outside locks and end up with deadlocks.
Hence, introduce ref-counting for l2cap_conn objects. This doesn't affect
l2cap internals at all, as they use a direct synchronization.
We also keep a reference to the parent hci_conn for locking purposes as
l2cap_conn depends on this. This doesn't affect the connection itself but
only the lifetime of the (dead) object.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
| -rw-r--r-- | include/net/bluetooth/l2cap.h | 4 | ||||
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 25 |
2 files changed, 28 insertions, 1 deletions
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 278830ef92cd..7b4cc5b98535 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -583,6 +583,7 @@ struct l2cap_conn { struct list_head chan_l; struct mutex chan_lock; + struct kref ref; }; #define L2CAP_INFO_CL_MTU_REQ_SENT 0x01 @@ -813,4 +814,7 @@ void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan, u8 status); void __l2cap_physical_cfm(struct l2cap_chan *chan, int result); +void l2cap_conn_get(struct l2cap_conn *conn); +void l2cap_conn_put(struct l2cap_conn *conn); + #endif /* __L2CAP_H */ diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index e09b89be1c4d..be9ad89339cd 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1486,7 +1486,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err) } hcon->l2cap_data = NULL; - kfree(conn); + conn->hchan = NULL; + l2cap_conn_put(conn); } static void security_timeout(struct work_struct *work) @@ -1520,8 +1521,10 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) return NULL; } + kref_init(&conn->ref); hcon->l2cap_data = conn; conn->hcon = hcon; + hci_conn_get(conn->hcon); conn->hchan = hchan; BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan); @@ -1558,6 +1561,26 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon) return conn; } +static void l2cap_conn_free(struct kref *ref) +{ + struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref); + + hci_conn_put(conn->hcon); + kfree(conn); +} + +void l2cap_conn_get(struct l2cap_conn *conn) +{ + kref_get(&conn->ref); +} +EXPORT_SYMBOL(l2cap_conn_get); + +void l2cap_conn_put(struct l2cap_conn *conn) +{ + kref_put(&conn->ref, l2cap_conn_free); +} +EXPORT_SYMBOL(l2cap_conn_put); + /* ---- Socket interface ---- */ /* Find socket with psm and source / destination bdaddr. |