Return-Path: MIME-Version: 1.0 In-Reply-To: <20120210091816.GF28197@aemeltch-MOBL1> References: <1328797057-26331-1-git-send-email-Andrei.Emeltchenko.news@gmail.com> <1328797057-26331-16-git-send-email-Andrei.Emeltchenko.news@gmail.com> <20120210091816.GF28197@aemeltch-MOBL1> Date: Fri, 10 Feb 2012 16:31:26 -0200 Message-ID: Subject: Re: [RFCv3 15/16] Bluetooth: Use l2cap chan lock in socket connect From: Ulisses Furquim To: Emeltchenko Andrei , Ulisses Furquim , linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Andrei, On Fri, Feb 10, 2012 at 7:18 AM, Emeltchenko Andrei wrote: > Hi Ulisses, > > On Thu, Feb 09, 2012 at 04:25:11PM -0200, Ulisses Furquim wrote: >> > ? ? ? ?bacpy(src, conn->src); >> > >> > + ? ? ? l2cap_chan_unlock(chan); >> > ? ? ? ?l2cap_chan_add(conn, chan); >> > + ? ? ? l2cap_chan_lock(chan); >> >> Hum, do we really need to do this? Maybe l2cap_chan_add() can receive >> chan already locked? > > Then we have here order of locking changed and I have lockdep warnings. > > And here l2cap_chan_add used locked. Why the locked version and not __l2cap_chan_add()? >> >> > - ? ? ? __l2cap_state_change(chan, BT_CONNECT); >> > + ? ? ? l2cap_state_change(chan, BT_CONNECT); >> >> Why? Is there a problem moving the release_sock() call to we don't >> call the locked function here? >> >> > ? ? ? ?__set_chan_timer(chan, sk->sk_sndtimeo); >> > >> > ? ? ? ?if (hcon->state == BT_CONNECTED) { >> > ? ? ? ? ? ? ? ?if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { >> > ? ? ? ? ? ? ? ? ? ? ? ?__clear_chan_timer(chan); >> > ? ? ? ? ? ? ? ? ? ? ? ?if (l2cap_chan_check_security(chan)) >> > - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? __l2cap_state_change(chan, BT_CONNECTED); >> > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? l2cap_state_change(chan, BT_CONNECTED); >> >> And here as well. > > Then we would need to release lock before l2cap_do_start. Sure. >> >> > ? ? ? ? ? ? ? ?} else >> > ? ? ? ? ? ? ? ? ? ? ? ?l2cap_do_start(chan); > > > Best regards > Andrei Emeltchenko Regards, -- Ulisses Furquim ProFUSION embedded systems http://profusion.mobi Mobile: +55 19 9250 0942 Skype: ulissesffs