6lowpan: rework fragment-deleting routine
6lowpan module starts collecting incomming frames and fragments
right after lowpan_module_init() therefor it will be better to
clean unfinished fragments in lowpan_cleanup_module() function
instead of doing it when link goes down.
Changed spinlocks type to prevent deadlock with expired timer event
and removed unused one.
Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 2e790fb..6871ec1 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -113,7 +113,6 @@
struct lowpan_fragment {
struct sk_buff *skb; /* skb to be assembled */
- spinlock_t lock; /* concurency lock */
u16 length; /* length to be assemled */
u32 bytes_rcv; /* bytes received */
u16 tag; /* current fragment tag */
@@ -637,10 +636,7 @@
pr_debug("timer expired for frame with tag %d\n", entry->tag);
- spin_lock(&flist_lock);
list_del(&entry->list);
- spin_unlock(&flist_lock);
-
dev_kfree_skb(entry->skb);
kfree(entry);
}
@@ -727,7 +723,7 @@
* check if frame assembling with the same tag is
* already in progress
*/
- spin_lock(&flist_lock);
+ spin_lock_bh(&flist_lock);
list_for_each_entry(frame, &lowpan_fragments, list)
if (frame->tag == tag) {
@@ -761,9 +757,9 @@
if ((frame->bytes_rcv == frame->length) &&
frame->timer.expires > jiffies) {
/* if timer haven't expired - first of all delete it */
- del_timer(&frame->timer);
+ del_timer_sync(&frame->timer);
list_del(&frame->list);
- spin_unlock(&flist_lock);
+ spin_unlock_bh(&flist_lock);
dev_kfree_skb(skb);
skb = frame->skb;
@@ -774,7 +770,7 @@
break;
}
- spin_unlock(&flist_lock);
+ spin_unlock_bh(&flist_lock);
return kfree_skb(skb), 0;
}
@@ -929,7 +925,7 @@
return lowpan_skb_deliver(skb, &hdr);
unlock_and_drop:
- spin_unlock(&flist_lock);
+ spin_unlock_bh(&flist_lock);
drop:
kfree_skb(skb);
return -EINVAL;
@@ -1196,19 +1192,9 @@
struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
struct net_device *real_dev = lowpan_dev->real_dev;
struct lowpan_dev_record *entry, *tmp;
- struct lowpan_fragment *frame, *tframe;
ASSERT_RTNL();
- spin_lock(&flist_lock);
- list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
- del_timer(&frame->timer);
- list_del(&frame->list);
- dev_kfree_skb(frame->skb);
- kfree(frame);
- }
- spin_unlock(&flist_lock);
-
mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
if (entry->ldev == dev) {
@@ -1264,9 +1250,24 @@
static void __exit lowpan_cleanup_module(void)
{
+ struct lowpan_fragment *frame, *tframe;
+
lowpan_netlink_fini();
dev_remove_pack(&lowpan_packet_type);
+
+ /* Now 6lowpan packet_type is removed, so no new fragments are
+ * expected on RX, therefore that's the time to clean incomplete
+ * fragments.
+ */
+ spin_lock_bh(&flist_lock);
+ list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
+ del_timer_sync(&frame->timer);
+ list_del(&frame->list);
+ dev_kfree_skb(frame->skb);
+ kfree(frame);
+ }
+ spin_unlock_bh(&flist_lock);
}
module_init(lowpan_init_module);