Re: [PATCH] Bluetooth: Use non locking get_chan and explicit lock
From: Marcel Holtmann <marcel@holtmann.org>
Date: 2012-01-21 16:41:34
Hi Andrei,
quoted hunk ↗ jump to hunk
For receiving ACL packets use __l2cap_get_chan_by_scid which is not locking sk and explicitly lock sk after checking that it is exist. Code looks nicer since now it is surrounded by lock/release. Signed-off-by: Andrei Emeltchenko <redacted> --- net/bluetooth/l2cap_core.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index d16ad49..53dbfd3 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c@@ -4243,7 +4243,7 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk u16 tx_seq; int len; - chan = l2cap_get_chan_by_scid(conn, cid); + chan = __l2cap_get_chan_by_scid(conn, cid); if (!chan) { if (cid == L2CAP_CID_A2MP) { chan = a2mp_channel_create(conn, skb);@@ -4255,6 +4255,8 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk } sk = chan->sk; + if (sk) + lock_sock(sk);
this is the part I clearly do not like. This is pretty nasty conditional locking. We need to figure out something better. Regards Marcel