mac80211: Prepare mesh_table_grow to failing copy_node callback.

The mesh_path_node_copy() performs kmalloc() and thus - may fail
(well, it does not now, but I'm fixing this right now). Its caller -
the mesh_table_grow() - isn't prepared for such a trick yet.

This preparation is just flush the new hash and make copy_node()
return an int value.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 16 insertions, 4 deletions

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 697ef67f96b6..ca81d0065eb8 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -349,7 +349,7 @@ struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
 {
         struct mesh_table *newtbl;
         struct hlist_head *oldhash;
-        struct hlist_node *p;
+        struct hlist_node *p, *q;
         int err = 0;
         int i;
 
@@ -373,13 +373,24 @@ struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
         oldhash = tbl->hash_buckets;
         for (i = 0; i <= tbl->hash_mask; i++)
                 hlist_for_each(p, &oldhash[i])
-                        tbl->copy_node(p, newtbl);
+                        if (tbl->copy_node(p, newtbl) < 0)
+                                goto errcopy;
 
 endgrow:
         if (err)
                 return NULL;
         else
                 return newtbl;
+
+errcopy:
+        for (i = 0; i <= newtbl->hash_mask; i++) {
+                hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
+                        tbl->free_node(p, 0);
+        }
+        kfree(newtbl->hash_buckets);
+        kfree(newtbl->hashwlock);
+        kfree(newtbl);
+        return NULL;
 }
 
 /**
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 2e161f6d8288..669eafafe497 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -109,7 +109,7 @@ struct mesh_table {
         __u32 hash_rnd;                 /* Used for hash generation */
         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
         void (*free_node) (struct hlist_node *p, bool free_leafs);
-        void (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
+        int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
         int size_order;
         int mean_chain_len;
 };
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 0b6c4bfe3e78..512bfa112c6a 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -463,7 +463,7 @@ static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
         kfree(node);
 }
 
-static void mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
+static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
 {
         struct mesh_path *mpath;
         struct mpath_node *node, *new_node;
@@ -476,6 +476,7 @@ static void mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
         hash_idx = mesh_table_hash(mpath->dst, mpath->dev, newtbl);
         hlist_add_head(&new_node->list,
                         &newtbl->hash_buckets[hash_idx]);
+        return 0;
 }
 
 int mesh_pathtbl_init(void)