1 files changed, 18 insertions, 15 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 2bc1bc23d42e..247b7cc20c13 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -376,17 +376,12 @@ struct tcf_net {
 static unsigned int tcf_net_id;
 
 static int tcf_block_insert(struct tcf_block *block, struct net *net,
-                            u32 block_index, struct netlink_ext_ack *extack)
+                            struct netlink_ext_ack *extack)
 {
         struct tcf_net *tn = net_generic(net, tcf_net_id);
-        int err;
 
-        err = idr_alloc_u32(&tn->idr, block, &block_index, block_index,
-                            GFP_KERNEL);
-        if (err)
-                return err;
-        block->index = block_index;
-        return 0;
+        return idr_alloc_u32(&tn->idr, block, &block->index, block->index,
+                             GFP_KERNEL);
 }
 
 static void tcf_block_remove(struct tcf_block *block, struct net *net)
@@ -397,6 +392,7 @@ static void tcf_block_remove(struct tcf_block *block, struct net *net)
 }
 
 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
+                                          u32 block_index,
                                           struct netlink_ext_ack *extack)
 {
         struct tcf_block *block;
@@ -419,10 +415,13 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
                 err = -ENOMEM;
                 goto err_chain_create;
         }
-        block->net = qdisc_net(q);
         block->refcnt = 1;
         block->net = net;
-        block->q = q;
+        block->index = block_index;
+
+        /* Don't store q pointer for blocks which are shared */
+        if (!tcf_block_shared(block))
+                block->q = q;
         return block;
 
 err_chain_create:
@@ -518,13 +517,12 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
         }
 
         if (!block) {
-                block = tcf_block_create(net, q, extack);
+                block = tcf_block_create(net, q, ei->block_index, extack);
                 if (IS_ERR(block))
                         return PTR_ERR(block);
                 created = true;
-                if (ei->block_index) {
-                        err = tcf_block_insert(block, net,
-                                               ei->block_index, extack);
+                if (tcf_block_shared(block)) {
+                        err = tcf_block_insert(block, net, extack);
                         if (err)
                                 goto err_block_insert;
                 }
@@ -1399,13 +1397,18 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
                     nla_get_u32(tca[TCA_CHAIN]) != chain->index)
                         continue;
                 if (!tcf_chain_dump(chain, q, parent, skb, cb,
-                                    index_start, &index))
+                                    index_start, &index)) {
+                        err = -EMSGSIZE;
                         break;
+                }
         }
 
         cb->args[0] = index;
 
 out:
+        /* If we did no progress, the error (EMSGSIZE) is real */
+        if (skb->len == 0 && err)
+                return err;
         return skb->len;
 }