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authorMarcel Holtmann <marcel@holtmann.org>2009-08-22 14:19:26 -0700
committerMarcel Holtmann <marcel@holtmann.org>2009-08-22 14:19:26 -0700
commit9eba32b86d17ef87131fa0bce43c614904ab5781 (patch)
treecd7e40a026475b7e4ddb8bdc944e75bc5a18c250 /net/bluetooth
parent364f63519d94442ed373ac7da79033c8282df46a (diff)
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Bluetooth: Add extra device reference counting for connections
The device model itself has no real usable reference counting at the moment and this causes problems if parents are deleted before their children. The device model itself handles the memory details of this correctly, but the uevent order is not consistent. This causes various problems for systems like HAL or even X. So until device_put() does a proper cleanup, the device for Bluetooth connection will be protected with an extra reference counting to ensure the correct order of uevents when connections are terminated. This is not an automatic feature. Higher Bluetooth layers like HIDP or BNEP should grab this new reference to ensure that their uevents are send before the ones from the parent device. Based on a report by Brian Rogers <brian@xyzw.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/hci_conn.c17
-rw-r--r--net/bluetooth/hci_event.c2
2 files changed, 18 insertions, 1 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index fa47d5d84f5..a9750984f77 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -246,6 +246,8 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
if (hdev->notify)
hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
+ atomic_set(&conn->devref, 0);
+
hci_conn_init_sysfs(conn);
tasklet_enable(&hdev->tx_task);
@@ -288,7 +290,7 @@ int hci_conn_del(struct hci_conn *conn)
skb_queue_purge(&conn->data_q);
- hci_conn_del_sysfs(conn);
+ hci_conn_put_device(conn);
hci_dev_put(hdev);
@@ -583,6 +585,19 @@ void hci_conn_check_pending(struct hci_dev *hdev)
hci_dev_unlock(hdev);
}
+void hci_conn_hold_device(struct hci_conn *conn)
+{
+ atomic_inc(&conn->devref);
+}
+EXPORT_SYMBOL(hci_conn_hold_device);
+
+void hci_conn_put_device(struct hci_conn *conn)
+{
+ if (atomic_dec_and_test(&conn->devref))
+ hci_conn_del_sysfs(conn);
+}
+EXPORT_SYMBOL(hci_conn_put_device);
+
int hci_get_conn_list(void __user *arg)
{
struct hci_conn_list_req req, *cl;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 184ba0a88ec..e99fe385fba 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -887,6 +887,7 @@ static inline void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *s
} else
conn->state = BT_CONNECTED;
+ hci_conn_hold_device(conn);
hci_conn_add_sysfs(conn);
if (test_bit(HCI_AUTH, &hdev->flags))
@@ -1693,6 +1694,7 @@ static inline void hci_sync_conn_complete_evt(struct hci_dev *hdev, struct sk_bu
conn->handle = __le16_to_cpu(ev->handle);
conn->state = BT_CONNECTED;
+ hci_conn_hold_device(conn);
hci_conn_add_sysfs(conn);
break;