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Commit 33c34c5e authored by alex.bluesman.smirnov@gmail.com's avatar alex.bluesman.smirnov@gmail.com Committed by David S. Miller
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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: default avatarAlexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent abbee2ef

net/ieee802154/6lowpan.c

+20 −19
Original line number Diff line number Diff line
@@ -113,7 +113,6 @@ struct lowpan_dev_record { 


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 @@ static void lowpan_fragment_timer_expired(unsigned long entry_addr) 


	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 @@ lowpan_process_data(struct sk_buff *skb) 
		 * 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 @@ lowpan_process_data(struct sk_buff *skb) 
		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 @@ lowpan_process_data(struct sk_buff *skb) 


			break;

		}

		spin_unlock(&flist_lock);

		spin_unlock_bh(&flist_lock);



		return kfree_skb(skb), 0;

	}
@@ -929,7 +925,7 @@ lowpan_process_data(struct sk_buff *skb) 
	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 @@ static void lowpan_dellink(struct net_device *dev, struct list_head *head) 
	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 @@ out: 


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);