There's no need to test whether a (delayed) work item in pending
before queueing, flushing or cancelling it. Most uses are unnecessary
and quite a few of them are buggy.
Reimplement l2cap_set_timer() such that it uses mod_delayed_work() or
schedule_delayed_work() depending on a new param @override and let the
users specify whether to override or not instead of using
delayed_work_pending().
Only compile tested.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
Cc: linux-bluetooth@xxxxxxxxxxxxxxx
---
Please let me know how this patch should be routed. I can take it
through the workqueue tree if necessary.
Thanks.
include/net/bluetooth/l2cap.h | 24 ++++++++++++++++--------
net/bluetooth/l2cap_core.c | 7 +++----
2 files changed, 19 insertions(+), 12 deletions(-)
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 7588ef4..f12cbeb 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -718,17 +718,25 @@ static inline void l2cap_chan_unlock(struct l2cap_chan *chan)
}
static inline void l2cap_set_timer(struct l2cap_chan *chan,
- struct delayed_work *work, long timeout)
+ struct delayed_work *work, long timeout,
+ bool override)
{
+ bool was_pending;
+
BT_DBG("chan %p state %s timeout %ld", chan,
state_to_string(chan->state), timeout);
- /* If delayed work cancelled do not hold(chan)
- since it is already done with previous set_timer */
- if (!cancel_delayed_work(work))
- l2cap_chan_hold(chan);
+ /* @work should hold a reference to @chan */
+ l2cap_chan_hold(chan);
+
+ if (override)
+ was_pending = mod_delayed_work(system_wq, work, timeout);
+ else
+ was_pending = !schedule_delayed_work(work, timeout);
- schedule_delayed_work(work, timeout);
+ /* if @work was already pending, lose the extra ref */
+ if (was_pending)
+ l2cap_chan_put(chan);
}
static inline bool l2cap_clear_timer(struct l2cap_chan *chan,
@@ -745,12 +753,12 @@ static inline bool l2cap_clear_timer(struct l2cap_chan *chan,
return ret;
}
-#define __set_chan_timer(c, t) l2cap_set_timer(c, &c->chan_timer, (t))
+#define __set_chan_timer(c, t) l2cap_set_timer(c, &c->chan_timer, (t), true)
#define __clear_chan_timer(c) l2cap_clear_timer(c, &c->chan_timer)
#define __clear_retrans_timer(c) l2cap_clear_timer(c, &c->retrans_timer)
#define __clear_monitor_timer(c) l2cap_clear_timer(c, &c->monitor_timer)
#define __set_ack_timer(c) l2cap_set_timer(c, &chan->ack_timer, \
- msecs_to_jiffies(L2CAP_DEFAULT_ACK_TO));
+ msecs_to_jiffies(L2CAP_DEFAULT_ACK_TO), true);
#define __clear_ack_timer(c) l2cap_clear_timer(c, &c->ack_timer)
static inline int __seq_offset(struct l2cap_chan *chan, __u16 seq1, __u16 seq2)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 2c78208..91db91c 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -246,10 +246,9 @@ static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
static void __set_retrans_timer(struct l2cap_chan *chan)
{
- if (!delayed_work_pending(&chan->monitor_timer) &&
- chan->retrans_timeout) {
+ if (chan->retrans_timeout) {
l2cap_set_timer(chan, &chan->retrans_timer,
- msecs_to_jiffies(chan->retrans_timeout));
+ msecs_to_jiffies(chan->retrans_timeout), false);
}
}
@@ -258,7 +257,7 @@ static void __set_monitor_timer(struct l2cap_chan *chan)
__clear_retrans_timer(chan);
if (chan->monitor_timeout) {
l2cap_set_timer(chan, &chan->monitor_timer,
- msecs_to_jiffies(chan->monitor_timeout));
+ msecs_to_jiffies(chan->monitor_timeout), true);
}
}
--
1.8.0.2
--
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