From: Emeltchenko Andrei <Andrei.Emeltchenko.news@gmail.com>
To: Ulisses Furquim <ulisses@profusion.mobi>
Cc: linux-bluetooth@vger.kernel.org
Subject: Re: [RFCv3 15/16] Bluetooth: Use l2cap chan lock in socket connect
Date: Mon, 13 Feb 2012 10:47:46 +0200 [thread overview]
Message-ID: <20120213084743.GA21179@aemeltch-MOBL1> (raw)
In-Reply-To: <CAA37ikZKJgtRoF-aK60W0AZr93u6zJ9T6=oB+6bzNLv80R=KbQ@mail.gmail.com>
Hi Ulisses,
On Fri, Feb 10, 2012 at 04:31:26PM -0200, Ulisses Furquim wrote:
> Hi Andrei,
>
> On Fri, Feb 10, 2012 at 7:18 AM, Emeltchenko Andrei
> <Andrei.Emeltchenko.news@gmail.com> 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()?
Because we need to lock addition channel to chan list and we are locked
only with chan->lock.
> >> > - __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.
I will check what can be done, currently including wide locks/unlocks would
significantly reduce readability of this part of the code.
Best regards
Andrei Emeltchenko
next prev parent reply other threads:[~2012-02-13 8:47 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 14:17 [RFCv3 00/16] Bluetooth: Change socket lock to l2cap_chan lock Emeltchenko Andrei
2012-02-09 14:17 ` [RFCv3 01/16] Bluetooth: trivial: Fix long line Emeltchenko Andrei
2012-02-09 14:26 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 02/16] Bluetooth: Revert to mutexes from RCU list Emeltchenko Andrei
2012-02-09 14:27 ` Marcel Holtmann
2012-02-09 17:54 ` Ulisses Furquim
2012-02-10 8:09 ` Emeltchenko Andrei
2012-02-09 18:37 ` Gustavo Padovan
2012-02-09 18:48 ` Ulisses Furquim
2012-02-09 14:17 ` [RFCv3 03/16] Bluetooth: Do not use sk lock in get_chan functions Emeltchenko Andrei
2012-02-09 14:28 ` Marcel Holtmann
2012-02-09 14:40 ` Emeltchenko Andrei
2012-02-09 18:08 ` Gustavo Padovan
2012-02-09 18:33 ` Ulisses Furquim
2012-02-10 8:16 ` Emeltchenko Andrei
2012-02-09 14:17 ` [RFCv3 04/16] Bluetooth: Add l2cap_chan_lock Emeltchenko Andrei
2012-02-09 19:24 ` Gustavo Padovan
2012-02-10 8:39 ` Emeltchenko Andrei
2012-02-09 14:17 ` [RFCv3 05/16] Bluetooth: Add locked and unlocked state_change Emeltchenko Andrei
2012-02-09 14:17 ` [RFCv3 06/16] Bluetooth: Add socket error function Emeltchenko Andrei
2012-02-09 14:30 ` Marcel Holtmann
2012-02-09 18:13 ` Gustavo Padovan
2012-02-10 8:46 ` Emeltchenko Andrei
2012-02-10 12:40 ` Gustavo Padovan
2012-02-09 14:17 ` [RFCv3 07/16] Bluetooth: Add unlocked __l2cap_chan_add function Emeltchenko Andrei
2012-02-09 14:31 ` Marcel Holtmann
2012-02-09 17:54 ` Ulisses Furquim
2012-02-10 8:53 ` Emeltchenko Andrei
2012-02-09 14:17 ` [RFCv3 08/16] Bluetooth: Use chan lock in timers Emeltchenko Andrei
2012-02-09 14:33 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 09/16] Bluetooth: Use chan lock in L2CAP sig commands Emeltchenko Andrei
2012-02-09 14:35 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 10/16] Bluetooth: Use chan lock in chan delete functions Emeltchenko Andrei
2012-02-09 14:36 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 11/16] Bluetooth: Use chan lock in L2CAP conn start Emeltchenko Andrei
2012-02-09 14:37 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 12/16] Bluetooth: Use chan lock in receiving data Emeltchenko Andrei
2012-02-09 14:38 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 13/16] Bluetooth: Change locking logic for conn/chan ready Emeltchenko Andrei
2012-02-09 14:39 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 14/16] Bluetooth: Change locking logic in security_cfm Emeltchenko Andrei
2012-02-09 14:40 ` Marcel Holtmann
2012-02-09 14:17 ` [RFCv3 15/16] Bluetooth: Use l2cap chan lock in socket connect Emeltchenko Andrei
2012-02-09 14:42 ` Marcel Holtmann
2012-02-09 18:25 ` Ulisses Furquim
2012-02-10 9:18 ` Emeltchenko Andrei
2012-02-10 18:31 ` Ulisses Furquim
2012-02-13 8:47 ` Emeltchenko Andrei [this message]
2012-02-14 1:12 ` Ulisses Furquim
2012-02-09 14:17 ` [RFCv3 16/16] Bluetooth: Remove socket lock check Emeltchenko Andrei
2012-02-09 14:43 ` Marcel Holtmann
2012-02-09 14:50 ` Emeltchenko Andrei
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