From cae1c11414912bf77a62aebd65ced321f0b9da51 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 27 Oct 2008 15:22:46 +0000 Subject: uwb: reference count reservations Reference counting the struct uwb_rsv's is safer and easier to get right than the transferring ownership of the structures from the PAL to reservation manager. This fixes an oops in the debug PAL after a reservation timed out. Signed-off-by: David Vrabel --- drivers/uwb/rsv.c | 48 ++++++++++++++++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 16 deletions(-) (limited to 'drivers/uwb/rsv.c') diff --git a/drivers/uwb/rsv.c b/drivers/uwb/rsv.c index e4facae46e0d..bcc41a4a6606 100644 --- a/drivers/uwb/rsv.c +++ b/drivers/uwb/rsv.c @@ -82,6 +82,23 @@ static void uwb_rsv_dump(struct uwb_rsv *rsv) dev_dbg(dev, "rsv %s -> %s: %s\n", owner, target, uwb_rsv_state_str(rsv->state)); } +static void uwb_rsv_release(struct kref *kref) +{ + struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref); + + kfree(rsv); +} + +static void uwb_rsv_get(struct uwb_rsv *rsv) +{ + kref_get(&rsv->kref); +} + +static void uwb_rsv_put(struct uwb_rsv *rsv) +{ + kref_put(&rsv->kref, uwb_rsv_release); +} + /* * Get a free stream index for a reservation. * @@ -325,6 +342,7 @@ static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc) INIT_LIST_HEAD(&rsv->rc_node); INIT_LIST_HEAD(&rsv->pal_node); + kref_init(&rsv->kref); init_timer(&rsv->timer); rsv->timer.function = uwb_rsv_timer; rsv->timer.data = (unsigned long)rsv; @@ -334,14 +352,6 @@ static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc) return rsv; } -static void uwb_rsv_free(struct uwb_rsv *rsv) -{ - uwb_dev_put(rsv->owner); - if (rsv->target.type == UWB_RSV_TARGET_DEV) - uwb_dev_put(rsv->target.dev); - kfree(rsv); -} - /** * uwb_rsv_create - allocate and initialize a UWB reservation structure * @rc: the radio controller @@ -375,23 +385,23 @@ void uwb_rsv_remove(struct uwb_rsv *rsv) if (rsv->state != UWB_RSV_STATE_NONE) uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE); del_timer_sync(&rsv->timer); - list_del(&rsv->rc_node); - uwb_rsv_free(rsv); + uwb_dev_put(rsv->owner); + if (rsv->target.type == UWB_RSV_TARGET_DEV) + uwb_dev_put(rsv->target.dev); + + list_del_init(&rsv->rc_node); + uwb_rsv_put(rsv); } /** * uwb_rsv_destroy - free a UWB reservation structure * @rsv: the reservation to free * - * The reservation will be terminated if it is pending or established. + * The reservation must already be terminated. */ void uwb_rsv_destroy(struct uwb_rsv *rsv) { - struct uwb_rc *rc = rsv->rc; - - mutex_lock(&rc->rsvs_mutex); - uwb_rsv_remove(rsv); - mutex_unlock(&rc->rsvs_mutex); + uwb_rsv_put(rsv); } EXPORT_SYMBOL_GPL(uwb_rsv_destroy); @@ -423,6 +433,7 @@ int uwb_rsv_establish(struct uwb_rsv *rsv) goto out; } + uwb_rsv_get(rsv); list_add_tail(&rsv->rc_node, &rc->reservations); rsv->owner = &rc->uwb_dev; uwb_dev_get(rsv->owner); @@ -478,9 +489,14 @@ EXPORT_SYMBOL_GPL(uwb_rsv_terminate); * * Reservation requests from peers are denied unless a PAL accepts it * by calling this function. + * + * The PAL call uwb_rsv_destroy() for all accepted reservations before + * calling uwb_pal_unregister(). */ void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv) { + uwb_rsv_get(rsv); + rsv->callback = cb; rsv->pal_priv = pal_priv; rsv->state = UWB_RSV_STATE_T_ACCEPTED; -- cgit v1.2.3