Re: [PATCH v2] Bluetooth: Fix error handling for l2cap_init()

["Gustavo F. Padovan" <padovan@profusion.mobi>]

Hi Anderson,

* Anderson Lizardo <anderson.lizardo@openbossa.org> [2010-11-24 11:13:30 -0=
400]:

> Hi Marcel,
>=20
> On Wed, Nov 24, 2010 at 8:42 AM, Marcel Holtmann <marcel@holtmann.org> wr=
ote:
> >> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> >> index 18a802c..7980e24 100644
> >> --- a/net/bluetooth/l2cap.c
> >> +++ b/net/bluetooth/l2cap.c
> >> @@ -4875,8 +4875,10 @@ static int __init l2cap_init(void)
> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 return err;
> >>
> >> =A0 =A0 =A0 _busy_wq =3D create_singlethread_workqueue("l2cap");
> >> - =A0 =A0 if (!_busy_wq)
> >> - =A0 =A0 =A0 =A0 =A0 =A0 goto error;
> >> + =A0 =A0 if (!_busy_wq) {
> >> + =A0 =A0 =A0 =A0 =A0 =A0 err =3D -ENOMEM;
> >> + =A0 =A0 =A0 =A0 =A0 =A0 goto error_busy_wq;
> >> + =A0 =A0 }
> >
> > aren't these returning PTR_ERR etc.?
>=20
> No, create_singlethread_workqueue() is just a wrapper around
> __alloc_workqueue_key(), which returns eiter a kzalloc()'ed pointer,
> or NULL on error. There is no way to get the actual reason of the
> error, but by taking a look at the function we can see most (if not
> all) errors are -ENOMEM. Thus why I used it here.
>=20
> Padovan: so how to proceed here: keep the patch as is and keep
> semantics, of make your proposed changes (with a slightly risk of a
> race condition and having _busy_wq NULL) ?

I'm not sure that my idea is right, so I have another option here. On
create_singlethread_workqueue error, just call proto_unregister() and
then return -ENOMEM, and destroy your workqueue under the label error.
This way we avoid create a new label and also have a simple error
handling there.

--=20
Gustavo F. Padovan
http://profusion.mobi