net: revert "net_sched: move tp->root allocation into fw_init()"
fw filter uses tp->root==NULL to check if it is the old method,
so it doesn't need allocation at all in this case. This patch
reverts the offending commit and adds some comments for old
method to make it obvious.
Fixes: 33f8b9ecdb15 ("net_sched: move tp->root allocation into fw_init()")
Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 715e01e..f23a3b6 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -33,7 +33,6 @@
struct fw_head {
u32 mask;
- bool mask_set;
struct fw_filter __rcu *ht[HTSIZE];
struct rcu_head rcu;
};
@@ -84,7 +83,7 @@
}
}
} else {
- /* old method */
+ /* Old method: classify the packet using its skb mark. */
if (id && (TC_H_MAJ(id) == 0 ||
!(TC_H_MAJ(id ^ tp->q->handle)))) {
res->classid = id;
@@ -114,14 +113,9 @@
static int fw_init(struct tcf_proto *tp)
{
- struct fw_head *head;
-
- head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
- if (head == NULL)
- return -ENOBUFS;
-
- head->mask_set = false;
- rcu_assign_pointer(tp->root, head);
+ /* We don't allocate fw_head here, because in the old method
+ * we don't need it at all.
+ */
return 0;
}
@@ -252,7 +246,7 @@
int err;
if (!opt)
- return handle ? -EINVAL : 0;
+ return handle ? -EINVAL : 0; /* Succeed if it is old method. */
err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
if (err < 0)
@@ -302,11 +296,17 @@
if (!handle)
return -EINVAL;
- if (!head->mask_set) {
- head->mask = 0xFFFFFFFF;
+ if (!head) {
+ u32 mask = 0xFFFFFFFF;
if (tb[TCA_FW_MASK])
- head->mask = nla_get_u32(tb[TCA_FW_MASK]);
- head->mask_set = true;
+ mask = nla_get_u32(tb[TCA_FW_MASK]);
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (!head)
+ return -ENOBUFS;
+ head->mask = mask;
+
+ rcu_assign_pointer(tp->root, head);
}
f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);