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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 <david.vrabel@csr.com>
This commit is contained in:
David Vrabel 2008-10-27 15:22:46 +00:00
parent b09ac64b7b
commit cae1c11414
4 changed files with 46 additions and 23 deletions
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7
drivers/usb/wusbcore/reservation.c
View File

@ -59,7 +59,6 @@ static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
case UWB_RSV_STATE_NONE:
dev_dbg(dev, "removed reservation\n");
wusbhc_bwa_set(wusbhc, 0, NULL);
wusbhc->rsv = NULL;
break;
default:
dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
@ -105,11 +104,11 @@ int wusbhc_rsv_establish(struct wusbhc *wusbhc)
/**
* wusbhc_rsv_terminate - terminate any cluster reservation
* wusbhc_rsv_terminate - terminate the cluster reservation
* @wusbhc: the WUSB host whose reservation is to be terminated
*/
void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
{
if (wusbhc->rsv)
uwb_rsv_terminate(wusbhc->rsv);
uwb_rsv_terminate(wusbhc->rsv);
uwb_rsv_destroy(wusbhc->rsv);
}

48
drivers/uwb/rsv.c
View File

@ -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;

13
drivers/uwb/uwb-debug.c
View File

@ -104,6 +104,11 @@ static void uwb_dbg_rsv_cb(struct uwb_rsv *rsv)
dev_dbg(dev, "debug: rsv %s -> %s: %s\n",
owner, target, uwb_rsv_state_str(rsv->state));
if (rsv->state == UWB_RSV_STATE_NONE) {
list_del(&rsv->pal_node);
uwb_rsv_destroy(rsv);
}
}
static int cmd_rsv_establish(struct uwb_rc *rc,
@ -153,11 +158,11 @@ static int cmd_rsv_terminate(struct uwb_rc *rc,
found = rsv;
break;
}
i++;
}
if (!found)
return -EINVAL;
list_del(&found->pal_node);
uwb_rsv_terminate(found);
return 0;
@ -287,8 +292,10 @@ static void uwb_dbg_new_rsv(struct uwb_rsv *rsv)
{
struct uwb_rc *rc = rsv->rc;
if (rc->dbg->accept)
if (rc->dbg->accept) {
list_add_tail(&rsv->pal_node, &rc->dbg->rsvs);
uwb_rsv_accept(rsv, uwb_dbg_rsv_cb, NULL);
}
}
/**
@ -336,7 +343,7 @@ void uwb_dbg_del_rc(struct uwb_rc *rc)
return;
list_for_each_entry_safe(rsv, t, &rc->dbg->rsvs, pal_node) {
uwb_rsv_destroy(rsv);
uwb_rsv_terminate(rsv);
}
uwb_pal_unregister(rc, &rc->dbg->pal);

1
include/linux/uwb.h
View File

@ -201,6 +201,7 @@ struct uwb_rsv {
struct uwb_rc *rc;
struct list_head rc_node;
struct list_head pal_node;
struct kref kref;
struct uwb_dev *owner;
struct uwb_rsv_target target;