From 33c34c5e9310622d5ed9a53d571f92824044020f Mon Sep 17 00:00:00 2001 From: "alex.bluesman.smirnov@gmail.com" Date: Tue, 10 Jul 2012 21:22:48 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ieee802154/6lowpan.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-) diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c index 2e790fbe848d..6871ec1b30f8 100644 --- a/net/ieee802154/6lowpan.c +++ b/net/ieee802154/6lowpan.c @@ -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); -- 2.20.1