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authorJiri Pirko <jiri@mellanox.com>2018-02-13 14:00:17 +0300
committerDavid S. Miller <davem@davemloft.net>2018-02-13 20:29:02 +0300
commit339c21d7c459238135d87da8fefbfd25d98bc375 (patch)
tree1c8eebd7b5da3e11d1374fe328dc4c254f47d4be /net/sched/cls_u32.c
parentbb047ddd145860ff24820320a21f03cf8c071b22 (diff)
downloadlinux-339c21d7c459238135d87da8fefbfd25d98bc375.tar.xz
net: sched: fix tc_u_common lookup
The offending commit wrongly assumes 1:1 mapping between block and q. However, there are multiple blocks for a single q for classful qdiscs. Since the obscure tc_u_common sharing mechanism expects it to be shared among a qdisc, fix it by storing q pointer in case the block is not shared. Reported-by: Paweł Staszewski <pstaszewski@itcare.pl> Reported-by: Cong Wang <xiyou.wangcong@gmail.com> Fixes: 7fa9d974f3c2 ("net: sched: cls_u32: use block instead of q in tc_u_common") Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/cls_u32.c')
-rw-r--r--net/sched/cls_u32.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 6c7601a530e3..ed8b6a24b9e9 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -96,7 +96,7 @@ struct tc_u_hnode {
struct tc_u_common {
struct tc_u_hnode __rcu *hlist;
- struct tcf_block *block;
+ void *ptr;
int refcnt;
struct idr handle_idr;
struct hlist_node hnode;
@@ -330,9 +330,25 @@ static struct hlist_head *tc_u_common_hash;
#define U32_HASH_SHIFT 10
#define U32_HASH_SIZE (1 << U32_HASH_SHIFT)
+static void *tc_u_common_ptr(const struct tcf_proto *tp)
+{
+ struct tcf_block *block = tp->chain->block;
+
+ /* The block sharing is currently supported only
+ * for classless qdiscs. In that case we use block
+ * for tc_u_common identification. In case the
+ * block is not shared, block->q is a valid pointer
+ * and we can use that. That works for classful qdiscs.
+ */
+ if (tcf_block_shared(block))
+ return block;
+ else
+ return block->q;
+}
+
static unsigned int tc_u_hash(const struct tcf_proto *tp)
{
- return hash_ptr(tp->chain->block, U32_HASH_SHIFT);
+ return hash_ptr(tc_u_common_ptr(tp), U32_HASH_SHIFT);
}
static struct tc_u_common *tc_u_common_find(const struct tcf_proto *tp)
@@ -342,7 +358,7 @@ static struct tc_u_common *tc_u_common_find(const struct tcf_proto *tp)
h = tc_u_hash(tp);
hlist_for_each_entry(tc, &tc_u_common_hash[h], hnode) {
- if (tc->block == tp->chain->block)
+ if (tc->ptr == tc_u_common_ptr(tp))
return tc;
}
return NULL;
@@ -371,7 +387,7 @@ static int u32_init(struct tcf_proto *tp)
kfree(root_ht);
return -ENOBUFS;
}
- tp_c->block = tp->chain->block;
+ tp_c->ptr = tc_u_common_ptr(tp);
INIT_HLIST_NODE(&tp_c->hnode);
idr_init(&tp_c->handle_idr);