mac80211: clean up mpath_move_to_queue()

Use skb_queue_walk_safe instead, and fix a few issues:

	- didn't free old skbs on moving
	- didn't react to failed skb alloc
	- needlessly held a local pointer to the destination frame queue
	- didn't check destination queue length before adding skb

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 21 insertions, 18 deletions

diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index faaa39bcfd10..e4d911ffd5d1 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -215,6 +215,9 @@ struct mesh_rmc {
 /* Maximum number of paths per interface */
 #define MESH_MAX_MPATHS         1024
 
+/* Number of frames buffered per destination for unresolved destinations */
+#define MESH_FRAME_QUEUE_LEN    10
+
 /* Public interfaces */
 /* Various */
 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 494bc39f61a4..47aeee2d8db1 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -17,8 +17,6 @@
 #define MAX_METRIC      0xffffffff
 #define ARITH_SHIFT     8
 
-/* Number of frames buffered per destination for unresolved destinations */
-#define MESH_FRAME_QUEUE_LEN    10
 #define MAX_PREQ_QUEUE_LEN      64
 
 /* Destination only */
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index b819d6b847d0..aa749818860e 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -279,40 +279,42 @@ static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
                                     struct mesh_path *from_mpath,
                                     bool copy)
 {
-        struct sk_buff *skb, *cp_skb = NULL;
-        struct sk_buff_head gateq, failq;
+        struct sk_buff *skb, *fskb, *tmp;
+        struct sk_buff_head failq;
         unsigned long flags;
-        int num_skbs;
 
         BUG_ON(gate_mpath == from_mpath);
         BUG_ON(!gate_mpath->next_hop);
 
-        __skb_queue_head_init(&gateq);
         __skb_queue_head_init(&failq);
 
         spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
         skb_queue_splice_init(&from_mpath->frame_queue, &failq);
         spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
 
-        num_skbs = skb_queue_len(&failq);
-
-        while (num_skbs--) {
-                skb = __skb_dequeue(&failq);
-                if (copy) {
-                        cp_skb = skb_copy(skb, GFP_ATOMIC);
-                        if (cp_skb)
-                                __skb_queue_tail(&failq, cp_skb);
+        skb_queue_walk_safe(&failq, fskb, tmp) {
+                if (skb_queue_len(&gate_mpath->frame_queue) >=
+                                  MESH_FRAME_QUEUE_LEN) {
+                        mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
+                        break;
                 }
 
+                skb = skb_copy(fskb, GFP_ATOMIC);
+                if (WARN_ON(!skb))
+                        break;
+
                 prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
-                __skb_queue_tail(&gateq, skb);
+                skb_queue_tail(&gate_mpath->frame_queue, skb);
+
+                if (copy)
+                        continue;
+
+                __skb_unlink(fskb, &failq);
+                kfree_skb(fskb);
         }
 
-        spin_lock_irqsave(&gate_mpath->frame_queue.lock, flags);
-        skb_queue_splice(&gateq, &gate_mpath->frame_queue);
         mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
                   gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
-        spin_unlock_irqrestore(&gate_mpath->frame_queue.lock, flags);
 
         if (!copy)
                 return;