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* [PATCH net-next v4 16/17] net: sched: refactor tcf_block_find() into standalone functions
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Refactor tcf_block_find() code into three standalone functions:
- __tcf_qdisc_find() to lookup Qdisc and increment its reference counter.
- __tcf_qdisc_cl_find() to lookup class.
- __tcf_block_find() to lookup block and increment its reference counter.

This change is necessary to allow netlink tc rule update handlers to call
these functions directly in order to conditionally take rtnl lock
according to Qdisc class ops flags before calling any of class ops
functions.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 net/sched/cls_api.c | 241 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 149 insertions(+), 92 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index e8ed461e94af..5f9373ee47ce 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1101,6 +1101,142 @@ static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
 	}
 }
 
+/* Lookup Qdisc and increments its reference counter.
+ * Set parent, if necessary.
+ */
+
+static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
+			    u32 *parent, int ifindex, bool rtnl_held,
+			    struct netlink_ext_ack *extack)
+{
+	const struct Qdisc_class_ops *cops;
+	struct net_device *dev;
+	int err = 0;
+
+	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+		return 0;
+
+	rcu_read_lock();
+
+	/* Find link */
+	dev = dev_get_by_index_rcu(net, ifindex);
+	if (!dev) {
+		rcu_read_unlock();
+		return -ENODEV;
+	}
+
+	/* Find qdisc */
+	if (!*parent) {
+		*q = dev->qdisc;
+		*parent = (*q)->handle;
+	} else {
+		*q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
+		if (!*q) {
+			NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
+			err = -EINVAL;
+			goto errout_rcu;
+		}
+	}
+
+	*q = qdisc_refcount_inc_nz(*q);
+	if (!*q) {
+		NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
+		err = -EINVAL;
+		goto errout_rcu;
+	}
+
+	/* Is it classful? */
+	cops = (*q)->ops->cl_ops;
+	if (!cops) {
+		NL_SET_ERR_MSG(extack, "Qdisc not classful");
+		err = -EINVAL;
+		goto errout_qdisc;
+	}
+
+	if (!cops->tcf_block) {
+		NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
+		err = -EOPNOTSUPP;
+		goto errout_qdisc;
+	}
+
+errout_rcu:
+	/* At this point we know that qdisc is not noop_qdisc,
+	 * which means that qdisc holds a reference to net_device
+	 * and we hold a reference to qdisc, so it is safe to release
+	 * rcu read lock.
+	 */
+	rcu_read_unlock();
+	return err;
+
+errout_qdisc:
+	rcu_read_unlock();
+
+	if (rtnl_held)
+		qdisc_put(*q);
+	else
+		qdisc_put_unlocked(*q);
+	*q = NULL;
+
+	return err;
+}
+
+static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
+			       int ifindex, struct netlink_ext_ack *extack)
+{
+	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+		return 0;
+
+	/* Do we search for filter, attached to class? */
+	if (TC_H_MIN(parent)) {
+		const struct Qdisc_class_ops *cops = q->ops->cl_ops;
+
+		*cl = cops->find(q, parent);
+		if (*cl == 0) {
+			NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
+			return -ENOENT;
+		}
+	}
+
+	return 0;
+}
+
+static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
+					  unsigned long cl, int ifindex,
+					  u32 block_index,
+					  struct netlink_ext_ack *extack)
+{
+	struct tcf_block *block;
+
+	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
+		block = tcf_block_refcnt_get(net, block_index);
+		if (!block) {
+			NL_SET_ERR_MSG(extack, "Block of given index was not found");
+			return ERR_PTR(-EINVAL);
+		}
+	} else {
+		const struct Qdisc_class_ops *cops = q->ops->cl_ops;
+
+		block = cops->tcf_block(q, cl, extack);
+		if (!block)
+			return ERR_PTR(-EINVAL);
+
+		if (tcf_block_shared(block)) {
+			NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
+			return ERR_PTR(-EOPNOTSUPP);
+		}
+
+		/* Always take reference to block in order to support execution
+		 * of rules update path of cls API without rtnl lock. Caller
+		 * must release block when it is finished using it. 'if' block
+		 * of this conditional obtain reference to block by calling
+		 * tcf_block_refcnt_get().
+		 */
+		refcount_inc(&block->refcnt);
+	}
+
+	return block;
+}
+
 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 			    struct tcf_block_ext_info *ei, bool rtnl_held)
 {
@@ -1146,106 +1282,27 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
 	struct tcf_block *block;
 	int err = 0;
 
-	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
-		block = tcf_block_refcnt_get(net, block_index);
-		if (!block) {
-			NL_SET_ERR_MSG(extack, "Block of given index was not found");
-			return ERR_PTR(-EINVAL);
-		}
-	} else {
-		const struct Qdisc_class_ops *cops;
-		struct net_device *dev;
-
-		rcu_read_lock();
-
-		/* Find link */
-		dev = dev_get_by_index_rcu(net, ifindex);
-		if (!dev) {
-			rcu_read_unlock();
-			return ERR_PTR(-ENODEV);
-		}
-
-		/* Find qdisc */
-		if (!*parent) {
-			*q = dev->qdisc;
-			*parent = (*q)->handle;
-		} else {
-			*q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
-			if (!*q) {
-				NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
-				err = -EINVAL;
-				goto errout_rcu;
-			}
-		}
-
-		*q = qdisc_refcount_inc_nz(*q);
-		if (!*q) {
-			NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
-			err = -EINVAL;
-			goto errout_rcu;
-		}
-
-		/* Is it classful? */
-		cops = (*q)->ops->cl_ops;
-		if (!cops) {
-			NL_SET_ERR_MSG(extack, "Qdisc not classful");
-			err = -EINVAL;
-			goto errout_rcu;
-		}
-
-		if (!cops->tcf_block) {
-			NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
-			err = -EOPNOTSUPP;
-			goto errout_rcu;
-		}
-
-		/* At this point we know that qdisc is not noop_qdisc,
-		 * which means that qdisc holds a reference to net_device
-		 * and we hold a reference to qdisc, so it is safe to release
-		 * rcu read lock.
-		 */
-		rcu_read_unlock();
+	ASSERT_RTNL();
 
-		/* Do we search for filter, attached to class? */
-		if (TC_H_MIN(*parent)) {
-			*cl = cops->find(*q, *parent);
-			if (*cl == 0) {
-				NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
-				err = -ENOENT;
-				goto errout_qdisc;
-			}
-		}
+	err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
+	if (err)
+		goto errout;
 
-		/* And the last stroke */
-		block = cops->tcf_block(*q, *cl, extack);
-		if (!block) {
-			err = -EINVAL;
-			goto errout_qdisc;
-		}
-		if (tcf_block_shared(block)) {
-			NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
-			err = -EOPNOTSUPP;
-			goto errout_qdisc;
-		}
+	err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
+	if (err)
+		goto errout_qdisc;
 
-		/* Always take reference to block in order to support execution
-		 * of rules update path of cls API without rtnl lock. Caller
-		 * must release block when it is finished using it. 'if' block
-		 * of this conditional obtain reference to block by calling
-		 * tcf_block_refcnt_get().
-		 */
-		refcount_inc(&block->refcnt);
-	}
+	block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
+	if (IS_ERR(block))
+		goto errout_qdisc;
 
 	return block;
 
-errout_rcu:
-	rcu_read_unlock();
 errout_qdisc:
-	if (*q) {
+	if (*q)
 		qdisc_put(*q);
-		*q = NULL;
-	}
+errout:
+	*q = NULL;
 	return ERR_PTR(err);
 }
 
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 14/17] net: sched: extend proto ops to support unlocked classifiers
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Add 'rtnl_held' flag to tcf proto change, delete, destroy, dump, walk
functions to track rtnl lock status. Extend users of these function in cls
API to propagate rtnl lock status to them. This allows classifiers to
obtain rtnl lock when necessary and to pass rtnl lock status to extensions
and driver offload callbacks.

Add flags field to tcf proto ops. Add flag value to indicate that
classifier doesn't require rtnl lock.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/pkt_cls.h     |   2 +-
 include/net/sch_generic.h |  17 +++--
 net/sched/cls_api.c       | 168 +++++++++++++++++++++++++---------------------
 net/sched/cls_basic.c     |  12 ++--
 net/sched/cls_bpf.c       |  12 ++--
 net/sched/cls_cgroup.c    |  11 +--
 net/sched/cls_flow.c      |  13 ++--
 net/sched/cls_flower.c    |  13 ++--
 net/sched/cls_fw.c        |  13 ++--
 net/sched/cls_matchall.c  |  13 ++--
 net/sched/cls_route.c     |  12 ++--
 net/sched/cls_rsvp.h      |  13 ++--
 net/sched/cls_tcindex.c   |  15 +++--
 net/sched/cls_u32.c       |  12 ++--
 net/sched/sch_api.c       |   6 +-
 15 files changed, 191 insertions(+), 141 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 0e3b61016931..6a530bef9253 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -47,7 +47,7 @@ void tcf_chain_put_by_act(struct tcf_chain *chain);
 struct tcf_chain *tcf_get_next_chain(struct tcf_block *block,
 				     struct tcf_chain *chain);
 struct tcf_proto *tcf_get_next_proto(struct tcf_chain *chain,
-				     struct tcf_proto *tp);
+				     struct tcf_proto *tp, bool rtnl_held);
 void tcf_block_netif_keep_dst(struct tcf_block *block);
 int tcf_block_get(struct tcf_block **p_block,
 		  struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 410dda80ca62..365801c2a4f5 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -273,7 +273,7 @@ struct tcf_proto_ops {
 					    const struct tcf_proto *,
 					    struct tcf_result *);
 	int			(*init)(struct tcf_proto*);
-	void			(*destroy)(struct tcf_proto *tp,
+	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
 					   struct netlink_ext_ack *extack);
 
 	void*			(*get)(struct tcf_proto*, u32 handle);
@@ -281,12 +281,13 @@ struct tcf_proto_ops {
 	int			(*change)(struct net *net, struct sk_buff *,
 					struct tcf_proto*, unsigned long,
 					u32 handle, struct nlattr **,
-					void **, bool,
+					void **, bool, bool,
 					struct netlink_ext_ack *);
 	int			(*delete)(struct tcf_proto *tp, void *arg,
-					  bool *last,
+					  bool *last, bool rtnl_held,
 					  struct netlink_ext_ack *);
-	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
+	void			(*walk)(struct tcf_proto *tp,
+					struct tcf_walker *arg, bool rtnl_held);
 	int			(*reoffload)(struct tcf_proto *tp, bool add,
 					     tc_setup_cb_t *cb, void *cb_priv,
 					     struct netlink_ext_ack *extack);
@@ -299,12 +300,18 @@ struct tcf_proto_ops {
 
 	/* rtnetlink specific */
 	int			(*dump)(struct net*, struct tcf_proto*, void *,
-					struct sk_buff *skb, struct tcmsg*);
+					struct sk_buff *skb, struct tcmsg*,
+					bool);
 	int			(*tmplt_dump)(struct sk_buff *skb,
 					      struct net *net,
 					      void *tmplt_priv);
 
 	struct module		*owner;
+	int			flags;
+};
+
+enum tcf_proto_ops_flags {
+	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
 };
 
 struct tcf_proto {
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8fe38aa180cf..e8ed461e94af 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -69,7 +69,8 @@ static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 }
 
 static const struct tcf_proto_ops *
-tcf_proto_lookup_ops(const char *kind, struct netlink_ext_ack *extack)
+tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	const struct tcf_proto_ops *ops;
 
@@ -77,9 +78,11 @@ tcf_proto_lookup_ops(const char *kind, struct netlink_ext_ack *extack)
 	if (ops)
 		return ops;
 #ifdef CONFIG_MODULES
-	rtnl_unlock();
+	if (rtnl_held)
+		rtnl_unlock();
 	request_module("cls_%s", kind);
-	rtnl_lock();
+	if (rtnl_held)
+		rtnl_lock();
 	ops = __tcf_proto_lookup_ops(kind);
 	/* We dropped the RTNL semaphore in order to perform
 	 * the module load. So, even if we succeeded in loading
@@ -162,6 +165,7 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 
 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 					  u32 prio, struct tcf_chain *chain,
+					  bool rtnl_held,
 					  struct netlink_ext_ack *extack)
 {
 	struct tcf_proto *tp;
@@ -171,7 +175,7 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 	if (!tp)
 		return ERR_PTR(-ENOBUFS);
 
-	tp->ops = tcf_proto_lookup_ops(kind, extack);
+	tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 	if (IS_ERR(tp->ops)) {
 		err = PTR_ERR(tp->ops);
 		goto errout;
@@ -202,20 +206,20 @@ static void tcf_proto_get(struct tcf_proto *tp)
 
 static void tcf_chain_put(struct tcf_chain *chain);
 
-static void tcf_proto_destroy(struct tcf_proto *tp,
+static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 			      struct netlink_ext_ack *extack)
 {
-	tp->ops->destroy(tp, extack);
+	tp->ops->destroy(tp, rtnl_held, extack);
 	tcf_chain_put(tp->chain);
 	module_put(tp->ops->owner);
 	kfree_rcu(tp, rcu);
 }
 
-static void tcf_proto_put(struct tcf_proto *tp,
+static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 			  struct netlink_ext_ack *extack)
 {
 	if (refcount_dec_and_test(&tp->refcnt))
-		tcf_proto_destroy(tp, extack);
+		tcf_proto_destroy(tp, rtnl_held, extack);
 }
 
 static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg)
@@ -223,21 +227,21 @@ static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg)
 	return -1;
 }
 
-static bool tcf_proto_is_empty(struct tcf_proto *tp)
+static bool tcf_proto_is_empty(struct tcf_proto *tp, bool rtnl_held)
 {
 	struct tcf_walker walker = { .fn = walker_noop, };
 
 	if (tp->ops->walk) {
-		tp->ops->walk(tp, &walker);
+		tp->ops->walk(tp, &walker, rtnl_held);
 		return !walker.stop;
 	}
 	return true;
 }
 
-static bool tcf_proto_check_delete(struct tcf_proto *tp)
+static bool tcf_proto_check_delete(struct tcf_proto *tp, bool rtnl_held)
 {
 	spin_lock(&tp->lock);
-	if (tcf_proto_is_empty(tp))
+	if (tcf_proto_is_empty(tp, rtnl_held))
 		tp->deleting = true;
 	spin_unlock(&tp->lock);
 	return tp->deleting;
@@ -506,7 +510,7 @@ static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 	__tcf_chain_put(chain, false, true);
 }
 
-static void tcf_chain_flush(struct tcf_chain *chain)
+static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 {
 	struct tcf_proto *tp, *tp_next;
 
@@ -519,7 +523,7 @@ static void tcf_chain_flush(struct tcf_chain *chain)
 
 	while (tp) {
 		tp_next = rcu_dereference_protected(tp->next, 1);
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 		tp = tp_next;
 	}
 }
@@ -1070,18 +1074,19 @@ __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
  */
 
 struct tcf_proto *
-tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp,
+		   bool rtnl_held)
 {
 	struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
 
 	if (tp)
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 
 	return tp_next;
 }
 EXPORT_SYMBOL(tcf_get_next_proto);
 
-static void tcf_block_flush_all_chains(struct tcf_block *block)
+static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
 {
 	struct tcf_chain *chain;
 
@@ -1092,12 +1097,12 @@ static void tcf_block_flush_all_chains(struct tcf_block *block)
 	     chain;
 	     chain = tcf_get_next_chain(block, chain)) {
 		tcf_chain_put_explicitly_created(chain);
-		tcf_chain_flush(chain);
+		tcf_chain_flush(chain, rtnl_held);
 	}
 }
 
 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
-			    struct tcf_block_ext_info *ei)
+			    struct tcf_block_ext_info *ei, bool rtnl_held)
 {
 	if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
 		/* Flushing/putting all chains will cause the block to be
@@ -1118,15 +1123,15 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 		if (free_block)
 			tcf_block_destroy(block);
 		else
-			tcf_block_flush_all_chains(block);
+			tcf_block_flush_all_chains(block, rtnl_held);
 	} else if (q) {
 		tcf_block_offload_unbind(block, q, ei);
 	}
 }
 
-static void tcf_block_refcnt_put(struct tcf_block *block)
+static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
 {
-	__tcf_block_put(block, NULL, NULL);
+	__tcf_block_put(block, NULL, NULL, rtnl_held);
 }
 
 /* Find tcf block.
@@ -1244,10 +1249,11 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
 	return ERR_PTR(err);
 }
 
-static void tcf_block_release(struct Qdisc *q, struct tcf_block *block)
+static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
+			      bool rtnl_held)
 {
 	if (!IS_ERR_OR_NULL(block))
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, rtnl_held);
 
 	if (q)
 		qdisc_put(q);
@@ -1358,7 +1364,7 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 	tcf_block_owner_del(block, q, ei->binder_type);
 err_block_owner_add:
 err_block_insert:
-	tcf_block_refcnt_put(block);
+	tcf_block_refcnt_put(block, true);
 	return err;
 }
 EXPORT_SYMBOL(tcf_block_get_ext);
@@ -1395,7 +1401,7 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 	tcf_chain0_head_change_cb_del(block, ei);
 	tcf_block_owner_del(block, q, ei->binder_type);
 
-	__tcf_block_put(block, q, ei);
+	__tcf_block_put(block, q, ei, true);
 }
 EXPORT_SYMBOL(tcf_block_put_ext);
 
@@ -1464,7 +1470,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 		for (tp = __tcf_get_next_proto(chain, NULL); tp;
 		     tp_prev = tp,
 			     tp = __tcf_get_next_proto(chain, tp),
-			     tcf_proto_put(tp_prev, NULL)) {
+			     tcf_proto_put(tp_prev, true, NULL)) {
 			if (tp->ops->reoffload) {
 				err = tp->ops->reoffload(tp, add, cb, cb_priv,
 							 extack);
@@ -1481,7 +1487,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 	return 0;
 
 err_playback_remove:
-	tcf_proto_put(tp, NULL);
+	tcf_proto_put(tp, true, NULL);
 	tcf_chain_put(chain);
 	tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
 				    extack);
@@ -1654,7 +1660,8 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 
 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 						    struct tcf_proto *tp_new,
-						    u32 protocol, u32 prio)
+						    u32 protocol, u32 prio,
+						    bool rtnl_held)
 {
 	struct tcf_chain_info chain_info;
 	struct tcf_proto *tp;
@@ -1669,10 +1676,10 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 	mutex_unlock(&chain->filter_chain_lock);
 
 	if (tp) {
-		tcf_proto_destroy(tp_new, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, NULL);
 		tp_new = tp;
 	} else if (err) {
-		tcf_proto_destroy(tp_new, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, NULL);
 		tp_new = ERR_PTR(err);
 	}
 
@@ -1680,7 +1687,7 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 }
 
 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
-				      struct tcf_proto *tp,
+				      struct tcf_proto *tp, bool rtnl_held,
 				      struct netlink_ext_ack *extack)
 {
 	struct tcf_chain_info chain_info;
@@ -1705,7 +1712,7 @@ static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
 	 * concurrently.
 	 * Mark tp for deletion if it is empty.
 	 */
-	if (!tp_iter || !tcf_proto_check_delete(tp)) {
+	if (!tp_iter || !tcf_proto_check_delete(tp, rtnl_held)) {
 		mutex_unlock(&chain->filter_chain_lock);
 		return;
 	}
@@ -1716,7 +1723,7 @@ static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
 	RCU_INIT_POINTER(*chain_info.pprev, next);
 	mutex_unlock(&chain->filter_chain_lock);
 
-	tcf_proto_put(tp, extack);
+	tcf_proto_put(tp, rtnl_held, extack);
 }
 
 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
@@ -1755,7 +1762,8 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 			 struct tcf_proto *tp, struct tcf_block *block,
 			 struct Qdisc *q, u32 parent, void *fh,
-			 u32 portid, u32 seq, u16 flags, int event)
+			 u32 portid, u32 seq, u16 flags, int event,
+			 bool rtnl_held)
 {
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
@@ -1783,7 +1791,8 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 	if (!fh) {
 		tcm->tcm_handle = 0;
 	} else {
-		if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
+		if (tp->ops->dump &&
+		    tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
 			goto nla_put_failure;
 	}
 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
@@ -1798,7 +1807,8 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 			  struct nlmsghdr *n, struct tcf_proto *tp,
 			  struct tcf_block *block, struct Qdisc *q,
-			  u32 parent, void *fh, int event, bool unicast)
+			  u32 parent, void *fh, int event, bool unicast,
+			  bool rtnl_held)
 {
 	struct sk_buff *skb;
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -1808,7 +1818,8 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 		return -ENOBUFS;
 
 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, event) <= 0) {
+			  n->nlmsg_seq, n->nlmsg_flags, event,
+			  rtnl_held) <= 0) {
 		kfree_skb(skb);
 		return -EINVAL;
 	}
@@ -1824,7 +1835,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 			      struct nlmsghdr *n, struct tcf_proto *tp,
 			      struct tcf_block *block, struct Qdisc *q,
 			      u32 parent, void *fh, bool unicast, bool *last,
-			      struct netlink_ext_ack *extack)
+			      bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct sk_buff *skb;
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -1835,13 +1846,14 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 		return -ENOBUFS;
 
 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
+			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
+			  rtnl_held) <= 0) {
 		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
 		kfree_skb(skb);
 		return -EINVAL;
 	}
 
-	err = tp->ops->delete(tp, fh, last, extack);
+	err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
 	if (err) {
 		kfree_skb(skb);
 		return err;
@@ -1860,14 +1872,15 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 				 struct tcf_block *block, struct Qdisc *q,
 				 u32 parent, struct nlmsghdr *n,
-				 struct tcf_chain *chain, int event)
+				 struct tcf_chain *chain, int event,
+				 bool rtnl_held)
 {
 	struct tcf_proto *tp;
 
-	for (tp = tcf_get_next_proto(chain, NULL);
-	     tp; tp = tcf_get_next_proto(chain, tp))
+	for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
+	     tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
 		tfilter_notify(net, oskb, n, tp, block,
-			       q, parent, NULL, event, false);
+			       q, parent, NULL, event, false, rtnl_held);
 }
 
 static void tfilter_put(struct tcf_proto *tp, void *fh)
@@ -1896,6 +1909,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	void *fh;
 	int err;
 	int tp_created;
+	bool rtnl_held = true;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -1987,14 +2001,16 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 		mutex_unlock(&chain->filter_chain_lock);
 		tp_new = tcf_proto_create(nla_data(tca[TCA_KIND]),
-					  protocol, prio, chain, extack);
+					  protocol, prio, chain, rtnl_held,
+					  extack);
 		if (IS_ERR(tp_new)) {
 			err = PTR_ERR(tp_new);
 			goto errout_tp;
 		}
 
 		tp_created = 1;
-		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio);
+		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
+						rtnl_held);
 		if (IS_ERR(tp)) {
 			err = PTR_ERR(tp);
 			goto errout_tp;
@@ -2032,24 +2048,24 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
-			      extack);
+			      rtnl_held, extack);
 	if (err == 0) {
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
-			       RTM_NEWTFILTER, false);
+			       RTM_NEWTFILTER, false, rtnl_held);
 		tfilter_put(tp, fh);
 	}
 
 errout:
 	if (err && tp_created)
-		tcf_chain_tp_delete_empty(chain, tp, NULL);
+		tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
 errout_tp:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		if (!tp_created)
 			tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	if (err == -EAGAIN)
 		/* Replay the request. */
 		goto replay;
@@ -2078,6 +2094,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
+	bool rtnl_held = true;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -2127,8 +2144,8 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	if (prio == 0) {
 		tfilter_notify_chain(net, skb, block, q, parent, n,
-				     chain, RTM_DELTFILTER);
-		tcf_chain_flush(chain);
+				     chain, RTM_DELTFILTER, rtnl_held);
+		tcf_chain_flush(chain, rtnl_held);
 		err = 0;
 		goto errout;
 	}
@@ -2148,9 +2165,9 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		tcf_chain_tp_remove(chain, &chain_info, tp);
 		mutex_unlock(&chain->filter_chain_lock);
 
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
-			       RTM_DELTFILTER, false);
+			       RTM_DELTFILTER, false, rtnl_held);
 		err = 0;
 		goto errout;
 	}
@@ -2166,20 +2183,21 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 		err = tfilter_del_notify(net, skb, n, tp, block,
 					 q, parent, fh, false, &last,
-					 extack);
+					 rtnl_held, extack);
+
 		if (err)
 			goto errout;
 		if (last)
-			tcf_chain_tp_delete_empty(chain, tp, extack);
+			tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
 	}
 
 errout:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	return err;
 
 errout_locked:
@@ -2205,6 +2223,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
+	bool rtnl_held = true;
 
 	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
 	if (err < 0)
@@ -2263,7 +2282,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		err = -ENOENT;
 	} else {
 		err = tfilter_notify(net, skb, n, tp, block, q, parent,
-				     fh, RTM_NEWTFILTER, true);
+				     fh, RTM_NEWTFILTER, true, rtnl_held);
 		if (err < 0)
 			NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
 	}
@@ -2272,10 +2291,10 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	return err;
 }
 
@@ -2296,7 +2315,7 @@ static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 	return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
 			     n, NETLINK_CB(a->cb->skb).portid,
 			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
-			     RTM_NEWTFILTER);
+			     RTM_NEWTFILTER, true);
 }
 
 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
@@ -2313,7 +2332,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 	     tp;
 	     tp_prev = tp,
 		     tp = __tcf_get_next_proto(chain, tp),
-		     tcf_proto_put(tp_prev, NULL),
+		     tcf_proto_put(tp_prev, true, NULL),
 		     (*p_index)++) {
 		if (*p_index < index_start)
 			continue;
@@ -2330,9 +2349,8 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 			if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
 					  NETLINK_CB(cb->skb).portid,
 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
-					  RTM_NEWTFILTER) <= 0)
+					  RTM_NEWTFILTER, true) <= 0)
 				goto errout;
-
 			cb->args[1] = 1;
 		}
 		if (!tp->ops->walk)
@@ -2347,7 +2365,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 		arg.w.skip = cb->args[1] - 1;
 		arg.w.count = 0;
 		arg.w.cookie = cb->args[2];
-		tp->ops->walk(tp, &arg.w);
+		tp->ops->walk(tp, &arg.w, true);
 		cb->args[2] = arg.w.cookie;
 		cb->args[1] = arg.w.count + 1;
 		if (arg.w.stop)
@@ -2356,7 +2374,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 	return true;
 
 errout:
-	tcf_proto_put(tp, NULL);
+	tcf_proto_put(tp, true, NULL);
 	return false;
 }
 
@@ -2448,7 +2466,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, true);
 	cb->args[0] = index;
 
 out:
@@ -2569,7 +2587,7 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 	if (!tca[TCA_KIND])
 		return 0;
 
-	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), extack);
+	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), true, extack);
 	if (IS_ERR(ops))
 		return PTR_ERR(ops);
 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
@@ -2699,9 +2717,9 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
 		break;
 	case RTM_DELCHAIN:
 		tfilter_notify_chain(net, skb, block, q, parent, n,
-				     chain, RTM_DELTFILTER);
+				     chain, RTM_DELTFILTER, true);
 		/* Flush the chain first as the user requested chain removal. */
-		tcf_chain_flush(chain);
+		tcf_chain_flush(chain, true);
 		/* In case the chain was successfully deleted, put a reference
 		 * to the chain previously taken during addition.
 		 */
@@ -2722,7 +2740,7 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	tcf_chain_put(chain);
 errout_block:
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, true);
 	if (err == -EAGAIN)
 		/* Replay the request. */
 		goto replay;
@@ -2829,7 +2847,7 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, true);
 	cb->args[0] = index;
 
 out:
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index eaf9c02fe792..2383f449d2bc 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -107,7 +107,8 @@ static void basic_delete_filter_work(struct work_struct *work)
 	rtnl_unlock();
 }
 
-static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void basic_destroy(struct tcf_proto *tp, bool rtnl_held,
+			  struct netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f, *n;
@@ -126,7 +127,7 @@ static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
-			struct netlink_ext_ack *extack)
+			bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f = arg;
@@ -173,7 +174,7 @@ static int basic_set_parms(struct net *net, struct tcf_proto *tp,
 static int basic_change(struct net *net, struct sk_buff *in_skb,
 			struct tcf_proto *tp, unsigned long base, u32 handle,
 			struct nlattr **tca, void **arg, bool ovr,
-			struct netlink_ext_ack *extack)
+			bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	int err;
 	struct basic_head *head = rtnl_dereference(tp->root);
@@ -247,7 +248,8 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		       bool rtnl_held)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f;
@@ -274,7 +276,7 @@ static void basic_bind_class(void *fh, u32 classid, unsigned long cl)
 }
 
 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		      struct sk_buff *skb, struct tcmsg *t)
+		      struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct tc_basic_pcnt gpf = {};
 	struct basic_filter *f = fh;
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 656b3423ad35..062350c6621c 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -298,7 +298,7 @@ static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 }
 
 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
-			  struct netlink_ext_ack *extack)
+			  bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 
@@ -307,7 +307,7 @@ static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 	return 0;
 }
 
-static void cls_bpf_destroy(struct tcf_proto *tp,
+static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 			    struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
@@ -456,7 +456,8 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 			  struct tcf_proto *tp, unsigned long base,
 			  u32 handle, struct nlattr **tca,
-			  void **arg, bool ovr, struct netlink_ext_ack *extack)
+			  void **arg, bool ovr, bool rtnl_held,
+			  struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 	struct cls_bpf_prog *oldprog = *arg;
@@ -576,7 +577,7 @@ static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 }
 
 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
-			struct sk_buff *skb, struct tcmsg *tm)
+			struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 {
 	struct cls_bpf_prog *prog = fh;
 	struct nlattr *nest;
@@ -636,7 +637,8 @@ static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl)
 		prog->res.class = cl;
 }
 
-static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+			 bool rtnl_held)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 	struct cls_bpf_prog *prog;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 663ee1c6d606..1cef3b416094 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -78,7 +78,7 @@ static void cls_cgroup_destroy_work(struct work_struct *work)
 static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 			     struct tcf_proto *tp, unsigned long base,
 			     u32 handle, struct nlattr **tca,
-			     void **arg, bool ovr,
+			     void **arg, bool ovr, bool rtnl_held,
 			     struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[TCA_CGROUP_MAX + 1];
@@ -130,7 +130,7 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void cls_cgroup_destroy(struct tcf_proto *tp,
+static void cls_cgroup_destroy(struct tcf_proto *tp, bool rtnl_held,
 			       struct netlink_ext_ack *extack)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
@@ -145,12 +145,13 @@ static void cls_cgroup_destroy(struct tcf_proto *tp,
 }
 
 static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last,
-			     struct netlink_ext_ack *extack)
+			     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
 
-static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+			    bool rtnl_held)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
 
@@ -166,7 +167,7 @@ static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh,
-			   struct sk_buff *skb, struct tcmsg *t)
+			   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
 	struct nlattr *nest;
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 39a6407d4832..204e2edae8d5 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -391,7 +391,8 @@ static void flow_destroy_filter_work(struct work_struct *work)
 static int flow_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
-		       void **arg, bool ovr, struct netlink_ext_ack *extack)
+		       void **arg, bool ovr, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *fold, *fnew;
@@ -566,7 +567,7 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 }
 
 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
-		       struct netlink_ext_ack *extack)
+		       bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f = arg;
@@ -590,7 +591,8 @@ static int flow_init(struct tcf_proto *tp)
 	return 0;
 }
 
-static void flow_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void flow_destroy(struct tcf_proto *tp, bool rtnl_held,
+			 struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f, *next;
@@ -617,7 +619,7 @@ static void *flow_get(struct tcf_proto *tp, u32 handle)
 }
 
 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		     struct sk_buff *skb, struct tcmsg *t)
+		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct flow_filter *f = fh;
 	struct nlattr *nest;
@@ -677,7 +679,8 @@ static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
 	return -1;
 }
 
-static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		      bool rtnl_held)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index d187bda602fa..5663f2b35de0 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -465,7 +465,8 @@ static void fl_destroy_sleepable(struct work_struct *work)
 	module_put(THIS_MODULE);
 }
 
-static void fl_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void fl_destroy(struct tcf_proto *tp, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct fl_flow_mask *mask, *next_mask;
@@ -1300,7 +1301,8 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 static int fl_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca,
-		     void **arg, bool ovr, struct netlink_ext_ack *extack)
+		     void **arg, bool ovr, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *fold = *arg;
@@ -1433,7 +1435,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 }
 
 static int fl_delete(struct tcf_proto *tp, void *arg, bool *last,
-		     struct netlink_ext_ack *extack)
+		     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f = arg;
@@ -1445,7 +1447,8 @@ static int fl_delete(struct tcf_proto *tp, void *arg, bool *last,
 	return 0;
 }
 
-static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		    bool rtnl_held)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f;
@@ -2040,7 +2043,7 @@ static int fl_dump_key(struct sk_buff *skb, struct net *net,
 }
 
 static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		   struct sk_buff *skb, struct tcmsg *t)
+		   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct cls_fl_filter *f = fh;
 	struct nlattr *nest;
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index c8173ebb69f2..317151bae73b 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -139,7 +139,8 @@ static void fw_delete_filter_work(struct work_struct *work)
 	rtnl_unlock();
 }
 
-static void fw_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void fw_destroy(struct tcf_proto *tp, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f;
@@ -163,7 +164,7 @@ static void fw_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last,
-		     struct netlink_ext_ack *extack)
+		     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = arg;
@@ -250,7 +251,8 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 static int fw_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca, void **arg,
-		     bool ovr, struct netlink_ext_ack *extack)
+		     bool ovr, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = *arg;
@@ -354,7 +356,8 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		    bool rtnl_held)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	int h;
@@ -384,7 +387,7 @@ static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		   struct sk_buff *skb, struct tcmsg *t)
+		   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = fh;
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index 8848a147c4bf..a37137430e61 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -109,7 +109,8 @@ static int mall_replace_hw_filter(struct tcf_proto *tp,
 	return 0;
 }
 
-static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void mall_destroy(struct tcf_proto *tp, bool rtnl_held,
+			 struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 
@@ -160,7 +161,8 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 static int mall_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
-		       void **arg, bool ovr, struct netlink_ext_ack *extack)
+		       void **arg, bool ovr, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
@@ -233,12 +235,13 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 }
 
 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
-		       struct netlink_ext_ack *extack)
+		       bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
 
-static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		      bool rtnl_held)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 
@@ -280,7 +283,7 @@ static int mall_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
 }
 
 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		     struct sk_buff *skb, struct tcmsg *t)
+		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct tc_matchall_pcnt gpf = {};
 	struct cls_mall_head *head = fh;
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 44b26038c4c4..e590c3a2999d 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -276,7 +276,8 @@ static void route4_queue_work(struct route4_filter *f)
 	tcf_queue_work(&f->rwork, route4_delete_filter_work);
 }
 
-static void route4_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void route4_destroy(struct tcf_proto *tp, bool rtnl_held,
+			   struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	int h1, h2;
@@ -312,7 +313,7 @@ static void route4_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
-			 struct netlink_ext_ack *extack)
+			 bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	struct route4_filter *f = arg;
@@ -468,7 +469,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 static int route4_change(struct net *net, struct sk_buff *in_skb,
 			 struct tcf_proto *tp, unsigned long base, u32 handle,
 			 struct nlattr **tca, void **arg, bool ovr,
-			 struct netlink_ext_ack *extack)
+			 bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	struct route4_filter __rcu **fp;
@@ -560,7 +561,8 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+			bool rtnl_held)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	unsigned int h, h1;
@@ -597,7 +599,7 @@ static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int route4_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		       struct sk_buff *skb, struct tcmsg *t)
+		       struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct route4_filter *f = fh;
 	struct nlattr *nest;
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index 9dd9530e6a52..4d3836178fa5 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -312,7 +312,8 @@ static void rsvp_delete_filter(struct tcf_proto *tp, struct rsvp_filter *f)
 		__rsvp_delete_filter(f);
 }
 
-static void rsvp_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void rsvp_destroy(struct tcf_proto *tp, bool rtnl_held,
+			 struct netlink_ext_ack *extack)
 {
 	struct rsvp_head *data = rtnl_dereference(tp->root);
 	int h1, h2;
@@ -341,7 +342,7 @@ static void rsvp_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int rsvp_delete(struct tcf_proto *tp, void *arg, bool *last,
-		       struct netlink_ext_ack *extack)
+		       bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct rsvp_head *head = rtnl_dereference(tp->root);
 	struct rsvp_filter *nfp, *f = arg;
@@ -477,7 +478,8 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle,
 		       struct nlattr **tca,
-		       void **arg, bool ovr, struct netlink_ext_ack *extack)
+		       void **arg, bool ovr, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct rsvp_head *data = rtnl_dereference(tp->root);
 	struct rsvp_filter *f, *nfp;
@@ -655,7 +657,8 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		      bool rtnl_held)
 {
 	struct rsvp_head *head = rtnl_dereference(tp->root);
 	unsigned int h, h1;
@@ -689,7 +692,7 @@ static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int rsvp_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		     struct sk_buff *skb, struct tcmsg *t)
+		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct rsvp_filter *f = fh;
 	struct rsvp_session *s;
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index b7dc667b6ec0..14d6b4058045 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -173,7 +173,7 @@ static void tcindex_destroy_fexts_work(struct work_struct *work)
 }
 
 static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
-			  struct netlink_ext_ack *extack)
+			  bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
 	struct tcindex_filter_result *r = arg;
@@ -226,7 +226,7 @@ static int tcindex_destroy_element(struct tcf_proto *tp,
 {
 	bool last;
 
-	return tcindex_delete(tp, arg, &last, NULL);
+	return tcindex_delete(tp, arg, &last, false, NULL);
 }
 
 static void __tcindex_destroy(struct rcu_head *head)
@@ -499,7 +499,7 @@ static int
 tcindex_change(struct net *net, struct sk_buff *in_skb,
 	       struct tcf_proto *tp, unsigned long base, u32 handle,
 	       struct nlattr **tca, void **arg, bool ovr,
-	       struct netlink_ext_ack *extack)
+	       bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct nlattr *opt = tca[TCA_OPTIONS];
 	struct nlattr *tb[TCA_TCINDEX_MAX + 1];
@@ -522,7 +522,8 @@ tcindex_change(struct net *net, struct sk_buff *in_skb,
 				 tca[TCA_RATE], ovr, extack);
 }
 
-static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
+static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker,
+			 bool rtnl_held)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
 	struct tcindex_filter *f, *next;
@@ -558,7 +559,7 @@ static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
 	}
 }
 
-static void tcindex_destroy(struct tcf_proto *tp,
+static void tcindex_destroy(struct tcf_proto *tp, bool rtnl_held,
 			    struct netlink_ext_ack *extack)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
@@ -568,14 +569,14 @@ static void tcindex_destroy(struct tcf_proto *tp,
 	walker.count = 0;
 	walker.skip = 0;
 	walker.fn = tcindex_destroy_element;
-	tcindex_walk(tp, &walker);
+	tcindex_walk(tp, &walker, true);
 
 	call_rcu(&p->rcu, __tcindex_destroy);
 }
 
 
 static int tcindex_dump(struct net *net, struct tcf_proto *tp, void *fh,
-			struct sk_buff *skb, struct tcmsg *t)
+			struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
 	struct tcindex_filter_result *r = fh;
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index e891f30d42e9..27d29c04dcc9 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -629,7 +629,8 @@ static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
 	return -ENOENT;
 }
 
-static void u32_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void u32_destroy(struct tcf_proto *tp, bool rtnl_held,
+			struct netlink_ext_ack *extack)
 {
 	struct tc_u_common *tp_c = tp->data;
 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
@@ -663,7 +664,7 @@ static void u32_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int u32_delete(struct tcf_proto *tp, void *arg, bool *last,
-		      struct netlink_ext_ack *extack)
+		      bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct tc_u_hnode *ht = arg;
 	struct tc_u_common *tp_c = tp->data;
@@ -858,7 +859,7 @@ static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
 
 static int u32_change(struct net *net, struct sk_buff *in_skb,
 		      struct tcf_proto *tp, unsigned long base, u32 handle,
-		      struct nlattr **tca, void **arg, bool ovr,
+		      struct nlattr **tca, void **arg, bool ovr, bool rtnl_held,
 		      struct netlink_ext_ack *extack)
 {
 	struct tc_u_common *tp_c = tp->data;
@@ -1123,7 +1124,8 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		     bool rtnl_held)
 {
 	struct tc_u_common *tp_c = tp->data;
 	struct tc_u_hnode *ht;
@@ -1281,7 +1283,7 @@ static void u32_bind_class(void *fh, u32 classid, unsigned long cl)
 }
 
 static int u32_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		    struct sk_buff *skb, struct tcmsg *t)
+		    struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct tc_u_knode *n = fh;
 	struct tc_u_hnode *ht_up, *ht_down;
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 9a530cad2759..2283924fb56d 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1914,14 +1914,14 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
 	     chain = tcf_get_next_chain(block, chain)) {
 		struct tcf_proto *tp;
 
-		for (tp = tcf_get_next_proto(chain, NULL);
-		     tp; tp = tcf_get_next_proto(chain, tp)) {
+		for (tp = tcf_get_next_proto(chain, NULL, true);
+		     tp; tp = tcf_get_next_proto(chain, tp, true)) {
 			struct tcf_bind_args arg = {};
 
 			arg.w.fn = tcf_node_bind;
 			arg.classid = clid;
 			arg.cl = new_cl;
-			tp->ops->walk(tp, &arg.w);
+			tp->ops->walk(tp, &arg.w, true);
 		}
 	}
 }
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 01/17] net: sched: protect block state with mutex
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Currently, tcf_block doesn't use any synchronization mechanisms to protect
critical sections that manage lifetime of its chains. block->chain_list and
multiple variables in tcf_chain that control its lifetime assume external
synchronization provided by global rtnl lock. Converting chain reference
counting to atomic reference counters is not possible because cls API uses
multiple counters and flags to control chain lifetime, so all of them must
be synchronized in chain get/put code.

Use single per-block lock to protect block data and manage lifetime of all
chains on the block. Always take block->lock when accessing chain_list.
Chain get and put modify chain lifetime-management data and parent block's
chain_list, so take the lock in these functions. Verify block->lock state
with assertions in functions that expect to be called with the lock taken
and are called from multiple places. Take block->lock when accessing
filter_chain_list.

In order to allow parallel update of rules on single block, move all calls
to classifiers outside of critical sections protected by new block->lock.
Rearrange chain get and put functions code to only access protected chain
data while holding block lock:
- Rearrange code to only access chain reference counter and chain action
  reference counter while holding block lock.
- Extract code that requires block->lock from tcf_chain_destroy() into
  standalone tcf_chain_destroy() function that is called by
  __tcf_chain_put() in same critical section that changes chain reference
  counters.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
---

Changes from V3 to V4:
  - Extract code that manages chain 'explicitly_created' flag into
    standalone patch.

 include/net/sch_generic.h |  5 +++
 net/sched/cls_api.c       | 84 +++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 76 insertions(+), 13 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 7a4957599874..31b8ea66a47d 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -12,6 +12,7 @@
 #include <linux/list.h>
 #include <linux/refcount.h>
 #include <linux/workqueue.h>
+#include <linux/mutex.h>
 #include <net/gen_stats.h>
 #include <net/rtnetlink.h>
 
@@ -352,6 +353,10 @@ struct tcf_chain {
 };
 
 struct tcf_block {
+	/* Lock protects tcf_block and lifetime-management data of chains
+	 * attached to the block (refcnt, action_refcnt, explicitly_created).
+	 */
+	struct mutex lock;
 	struct list_head chain_list;
 	u32 index; /* block index for shared blocks */
 	refcount_t refcnt;
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 02cf6d2fa0e1..806e7158a7e8 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -201,6 +201,9 @@ static void tcf_proto_destroy(struct tcf_proto *tp,
 	kfree_rcu(tp, rcu);
 }
 
+#define ASSERT_BLOCK_LOCKED(block)					\
+	lockdep_assert_held(&(block)->lock)
+
 struct tcf_filter_chain_list_item {
 	struct list_head list;
 	tcf_chain_head_change_t *chain_head_change;
@@ -212,6 +215,8 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 {
 	struct tcf_chain *chain;
 
+	ASSERT_BLOCK_LOCKED(block);
+
 	chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 	if (!chain)
 		return NULL;
@@ -243,25 +248,51 @@ static void tcf_chain0_head_change(struct tcf_chain *chain,
 		tcf_chain_head_change_item(item, tp_head);
 }
 
-static void tcf_chain_destroy(struct tcf_chain *chain)
+/* Returns true if block can be safely freed. */
+
+static bool tcf_chain_detach(struct tcf_chain *chain)
 {
 	struct tcf_block *block = chain->block;
 
+	ASSERT_BLOCK_LOCKED(block);
+
 	list_del(&chain->list);
 	if (!chain->index)
 		block->chain0.chain = NULL;
+
+	if (list_empty(&block->chain_list) &&
+	    refcount_read(&block->refcnt) == 0)
+		return true;
+
+	return false;
+}
+
+static void tcf_block_destroy(struct tcf_block *block)
+{
+	mutex_destroy(&block->lock);
+	kfree_rcu(block, rcu);
+}
+
+static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
+{
+	struct tcf_block *block = chain->block;
+
 	kfree(chain);
-	if (list_empty(&block->chain_list) && !refcount_read(&block->refcnt))
-		kfree_rcu(block, rcu);
+	if (free_block)
+		tcf_block_destroy(block);
 }
 
 static void tcf_chain_hold(struct tcf_chain *chain)
 {
+	ASSERT_BLOCK_LOCKED(chain->block);
+
 	++chain->refcnt;
 }
 
 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
 {
+	ASSERT_BLOCK_LOCKED(chain->block);
+
 	/* In case all the references are action references, this
 	 * chain should not be shown to the user.
 	 */
@@ -273,6 +304,8 @@ static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
 {
 	struct tcf_chain *chain;
 
+	ASSERT_BLOCK_LOCKED(block);
+
 	list_for_each_entry(chain, &block->chain_list, list) {
 		if (chain->index == chain_index)
 			return chain;
@@ -287,31 +320,40 @@ static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
 					 u32 chain_index, bool create,
 					 bool by_act)
 {
-	struct tcf_chain *chain = tcf_chain_lookup(block, chain_index);
+	struct tcf_chain *chain = NULL;
+	bool is_first_reference;
 
+	mutex_lock(&block->lock);
+	chain = tcf_chain_lookup(block, chain_index);
 	if (chain) {
 		tcf_chain_hold(chain);
 	} else {
 		if (!create)
-			return NULL;
+			goto errout;
 		chain = tcf_chain_create(block, chain_index);
 		if (!chain)
-			return NULL;
+			goto errout;
 	}
 
 	if (by_act)
 		++chain->action_refcnt;
+	is_first_reference = chain->refcnt - chain->action_refcnt == 1;
+	mutex_unlock(&block->lock);
 
 	/* Send notification only in case we got the first
 	 * non-action reference. Until then, the chain acts only as
 	 * a placeholder for actions pointing to it and user ought
 	 * not know about them.
 	 */
-	if (chain->refcnt - chain->action_refcnt == 1 && !by_act)
+	if (is_first_reference && !by_act)
 		tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
 				RTM_NEWCHAIN, false);
 
 	return chain;
+
+errout:
+	mutex_unlock(&block->lock);
+	return chain;
 }
 
 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
@@ -330,17 +372,31 @@ static void tc_chain_tmplt_del(struct tcf_chain *chain);
 
 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act)
 {
+	struct tcf_block *block = chain->block;
+	bool is_last, free_block = false;
+	unsigned int refcnt;
+
+	mutex_lock(&block->lock);
 	if (by_act)
 		chain->action_refcnt--;
-	chain->refcnt--;
+
+	/* tc_chain_notify_delete can't be called while holding block lock.
+	 * However, when block is unlocked chain can be changed concurrently, so
+	 * save these to temporary variables.
+	 */
+	refcnt = --chain->refcnt;
+	is_last = refcnt - chain->action_refcnt == 0;
+	if (refcnt == 0)
+		free_block = tcf_chain_detach(chain);
+	mutex_unlock(&block->lock);
 
 	/* The last dropped non-action reference will trigger notification. */
-	if (chain->refcnt - chain->action_refcnt == 0 && !by_act)
+	if (is_last && !by_act)
 		tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false);
 
-	if (chain->refcnt == 0) {
+	if (refcnt == 0) {
 		tc_chain_tmplt_del(chain);
-		tcf_chain_destroy(chain);
+		tcf_chain_destroy(chain, free_block);
 	}
 }
 
@@ -772,6 +828,7 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 		NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
 		return ERR_PTR(-ENOMEM);
 	}
+	mutex_init(&block->lock);
 	INIT_LIST_HEAD(&block->chain_list);
 	INIT_LIST_HEAD(&block->cb_list);
 	INIT_LIST_HEAD(&block->owner_list);
@@ -835,7 +892,7 @@ static void tcf_block_put_all_chains(struct tcf_block *block)
 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 			    struct tcf_block_ext_info *ei)
 {
-	if (refcount_dec_and_test(&block->refcnt)) {
+	if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
 		/* Flushing/putting all chains will cause the block to be
 		 * deallocated when last chain is freed. However, if chain_list
 		 * is empty, block has to be manually deallocated. After block
@@ -844,6 +901,7 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 		 */
 		bool free_block = list_empty(&block->chain_list);
 
+		mutex_unlock(&block->lock);
 		if (tcf_block_shared(block))
 			tcf_block_remove(block, block->net);
 		if (!free_block)
@@ -853,7 +911,7 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 			tcf_block_offload_unbind(block, q, ei);
 
 		if (free_block)
-			kfree_rcu(block, rcu);
+			tcf_block_destroy(block);
 		else
 			tcf_block_put_all_chains(block);
 	} else if (q) {
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 11/17] net: sched: prevent insertion of new classifiers during chain flush
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Extend tcf_chain with 'flushing' flag. Use the flag to prevent insertion of
new classifier instances when chain flushing is in progress in order to
prevent resource leak when tcf_proto is created by unlocked users
concurrently.

Return EAGAIN error from tcf_chain_tp_insert_unique() to restart
tc_new_tfilter() and lookup the chain/proto again.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/sch_generic.h |  1 +
 net/sched/cls_api.c       | 35 +++++++++++++++++++++++++++++------
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 083e566fc380..e8cf36ed3e87 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -356,6 +356,7 @@ struct tcf_chain {
 	unsigned int refcnt;
 	unsigned int action_refcnt;
 	bool explicitly_created;
+	bool flushing;
 	const struct tcf_proto_ops *tmplt_ops;
 	void *tmplt_priv;
 };
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index c6452e3bfc6a..3038a82f6591 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -477,9 +477,12 @@ static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 	mutex_unlock(&block->lock);
 
 	/* The last dropped non-action reference will trigger notification. */
-	if (is_last && !by_act)
+	if (is_last && !by_act) {
 		tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain_index,
 				       block, NULL, 0, 0, false);
+		/* Last reference to chain, no need to lock. */
+		chain->flushing = false;
+	}
 
 	if (refcnt == 0) {
 		tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
@@ -511,6 +514,7 @@ static void tcf_chain_flush(struct tcf_chain *chain)
 	tp = tcf_chain_dereference(chain->filter_chain, chain);
 	RCU_INIT_POINTER(chain->filter_chain, NULL);
 	tcf_chain0_head_change(chain, NULL);
+	chain->flushing = true;
 	mutex_unlock(&chain->filter_chain_lock);
 
 	while (tp) {
@@ -1610,15 +1614,20 @@ static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
 	return tcf_chain_dereference(*chain_info->pprev, chain);
 }
 
-static void tcf_chain_tp_insert(struct tcf_chain *chain,
-				struct tcf_chain_info *chain_info,
-				struct tcf_proto *tp)
+static int tcf_chain_tp_insert(struct tcf_chain *chain,
+			       struct tcf_chain_info *chain_info,
+			       struct tcf_proto *tp)
 {
+	if (chain->flushing)
+		return -EAGAIN;
+
 	if (*chain_info->pprev == chain->filter_chain)
 		tcf_chain0_head_change(chain, tp);
 	tcf_proto_get(tp);
 	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
 	rcu_assign_pointer(*chain_info->pprev, tp);
+
+	return 0;
 }
 
 static void tcf_chain_tp_remove(struct tcf_chain *chain,
@@ -1649,18 +1658,22 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 {
 	struct tcf_chain_info chain_info;
 	struct tcf_proto *tp;
+	int err = 0;
 
 	mutex_lock(&chain->filter_chain_lock);
 
 	tp = tcf_chain_tp_find(chain, &chain_info,
 			       protocol, prio, false);
 	if (!tp)
-		tcf_chain_tp_insert(chain, &chain_info, tp_new);
+		err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
 	mutex_unlock(&chain->filter_chain_lock);
 
 	if (tp) {
 		tcf_proto_destroy(tp_new, NULL);
 		tp_new = tp;
+	} else if (err) {
+		tcf_proto_destroy(tp_new, NULL);
+		tp_new = ERR_PTR(err);
 	}
 
 	return tp_new;
@@ -1943,6 +1956,11 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	if (tp == NULL) {
 		struct tcf_proto *tp_new = NULL;
 
+		if (chain->flushing) {
+			err = -EAGAIN;
+			goto errout_locked;
+		}
+
 		/* Proto-tcf does not exist, create new one */
 
 		if (tca[TCA_KIND] == NULL || !protocol) {
@@ -1966,11 +1984,15 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 					  protocol, prio, chain, extack);
 		if (IS_ERR(tp_new)) {
 			err = PTR_ERR(tp_new);
-			goto errout;
+			goto errout_tp;
 		}
 
 		tp_created = 1;
 		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio);
+		if (IS_ERR(tp)) {
+			err = PTR_ERR(tp);
+			goto errout_tp;
+		}
 	} else {
 		mutex_unlock(&chain->filter_chain_lock);
 	}
@@ -2011,6 +2033,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	if (err && tp_created)
 		tcf_chain_tp_delete_empty(chain, tp, NULL);
+errout_tp:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
 			tcf_proto_put(tp, NULL);
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 07/17] net: sched: protect filter_chain list with filter_chain_lock mutex
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Extend tcf_chain with new filter_chain_lock mutex. Always lock the chain
when accessing filter_chain list, instead of relying on rtnl lock.
Dereference filter_chain with tcf_chain_dereference() lockdep macro to
verify that all users of chain_list have the lock taken.

Rearrange tp insert/remove code in tc_new_tfilter/tc_del_tfilter to execute
all necessary code while holding chain lock in order to prevent
invalidation of chain_info structure by potential concurrent change. This
also serializes calls to tcf_chain0_head_change(), which allows head change
callbacks to rely on filter_chain_lock for synchronization instead of rtnl
mutex.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/sch_generic.h |  17 +++++++
 net/sched/cls_api.c       | 111 +++++++++++++++++++++++++++++++++-------------
 net/sched/sch_generic.c   |   6 ++-
 3 files changed, 101 insertions(+), 33 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 31b8ea66a47d..85993d7efee6 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -341,6 +341,8 @@ struct qdisc_skb_cb {
 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
 
 struct tcf_chain {
+	/* Protects filter_chain. */
+	struct mutex filter_chain_lock;
 	struct tcf_proto __rcu *filter_chain;
 	struct list_head list;
 	struct tcf_block *block;
@@ -374,6 +376,21 @@ struct tcf_block {
 	struct rcu_head rcu;
 };
 
+#ifdef CONFIG_PROVE_LOCKING
+static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
+{
+	return lockdep_is_held(&chain->filter_chain_lock);
+}
+#else
+static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
+{
+	return true;
+}
+#endif /* #ifdef CONFIG_PROVE_LOCKING */
+
+#define tcf_chain_dereference(p, chain)					\
+	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
+
 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
 {
 	if (*flags & TCA_CLS_FLAGS_IN_HW)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 0dcce8b0c7b4..3fce30ae9a9b 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -221,6 +221,7 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 	if (!chain)
 		return NULL;
 	list_add_tail(&chain->list, &block->chain_list);
+	mutex_init(&chain->filter_chain_lock);
 	chain->block = block;
 	chain->index = chain_index;
 	chain->refcnt = 1;
@@ -280,6 +281,7 @@ static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
 {
 	struct tcf_block *block = chain->block;
 
+	mutex_destroy(&chain->filter_chain_lock);
 	kfree(chain);
 	if (free_block)
 		tcf_block_destroy(block);
@@ -443,9 +445,13 @@ static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 
 static void tcf_chain_flush(struct tcf_chain *chain)
 {
-	struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);
+	struct tcf_proto *tp;
 
+	mutex_lock(&chain->filter_chain_lock);
+	tp = tcf_chain_dereference(chain->filter_chain, chain);
 	tcf_chain0_head_change(chain, NULL);
+	mutex_unlock(&chain->filter_chain_lock);
+
 	while (tp) {
 		RCU_INIT_POINTER(chain->filter_chain, tp->next);
 		tcf_proto_destroy(tp, NULL);
@@ -785,11 +791,29 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
 
 	mutex_lock(&block->lock);
 	chain0 = block->chain0.chain;
-	if (chain0 && chain0->filter_chain)
-		tcf_chain_head_change_item(item, chain0->filter_chain);
-	list_add(&item->list, &block->chain0.filter_chain_list);
+	if (chain0)
+		tcf_chain_hold(chain0);
+	else
+		list_add(&item->list, &block->chain0.filter_chain_list);
 	mutex_unlock(&block->lock);
 
+	if (chain0) {
+		struct tcf_proto *tp_head;
+
+		mutex_lock(&chain0->filter_chain_lock);
+
+		tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
+		if (tp_head)
+			tcf_chain_head_change_item(item, tp_head);
+
+		mutex_lock(&block->lock);
+		list_add(&item->list, &block->chain0.filter_chain_list);
+		mutex_unlock(&block->lock);
+
+		mutex_unlock(&chain0->filter_chain_lock);
+		tcf_chain_put(chain0);
+	}
+
 	return 0;
 }
 
@@ -1464,9 +1488,10 @@ struct tcf_chain_info {
 	struct tcf_proto __rcu *next;
 };
 
-static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
+static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
+					   struct tcf_chain_info *chain_info)
 {
-	return rtnl_dereference(*chain_info->pprev);
+	return tcf_chain_dereference(*chain_info->pprev, chain);
 }
 
 static void tcf_chain_tp_insert(struct tcf_chain *chain,
@@ -1475,7 +1500,7 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain,
 {
 	if (*chain_info->pprev == chain->filter_chain)
 		tcf_chain0_head_change(chain, tp);
-	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
+	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
 	rcu_assign_pointer(*chain_info->pprev, tp);
 	tcf_chain_hold(chain);
 }
@@ -1484,7 +1509,7 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain,
 				struct tcf_chain_info *chain_info,
 				struct tcf_proto *tp)
 {
-	struct tcf_proto *next = rtnl_dereference(chain_info->next);
+	struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
 
 	if (tp == chain->filter_chain)
 		tcf_chain0_head_change(chain, next);
@@ -1502,7 +1527,8 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 
 	/* Check the chain for existence of proto-tcf with this priority */
 	for (pprev = &chain->filter_chain;
-	     (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
+	     (tp = tcf_chain_dereference(*pprev, chain));
+	     pprev = &tp->next) {
 		if (tp->prio >= prio) {
 			if (tp->prio == prio) {
 				if (prio_allocate ||
@@ -1710,12 +1736,13 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		goto errout;
 	}
 
+	mutex_lock(&chain->filter_chain_lock);
 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 			       prio, prio_allocate);
 	if (IS_ERR(tp)) {
 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
 		err = PTR_ERR(tp);
-		goto errout;
+		goto errout_locked;
 	}
 
 	if (tp == NULL) {
@@ -1724,29 +1751,37 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		if (tca[TCA_KIND] == NULL || !protocol) {
 			NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
 			err = -EINVAL;
-			goto errout;
+			goto errout_locked;
 		}
 
 		if (!(n->nlmsg_flags & NLM_F_CREATE)) {
 			NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
 			err = -ENOENT;
-			goto errout;
+			goto errout_locked;
 		}
 
 		if (prio_allocate)
-			prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
+			prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
+							       &chain_info));
 
+		mutex_unlock(&chain->filter_chain_lock);
 		tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
 				      protocol, prio, chain, extack);
 		if (IS_ERR(tp)) {
 			err = PTR_ERR(tp);
 			goto errout;
 		}
+
+		mutex_lock(&chain->filter_chain_lock);
+		tcf_chain_tp_insert(chain, &chain_info, tp);
+		mutex_unlock(&chain->filter_chain_lock);
 		tp_created = 1;
 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
 		err = -EINVAL;
-		goto errout;
+		goto errout_locked;
+	} else {
+		mutex_unlock(&chain->filter_chain_lock);
 	}
 
 	fh = tp->ops->get(tp, t->tcm_handle);
@@ -1772,15 +1807,11 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
 			      extack);
-	if (err == 0) {
-		if (tp_created)
-			tcf_chain_tp_insert(chain, &chain_info, tp);
+	if (err == 0)
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
 			       RTM_NEWTFILTER, false);
-	} else {
-		if (tp_created)
-			tcf_proto_destroy(tp, NULL);
-	}
+	else if (tp_created)
+		tcf_proto_destroy(tp, NULL);
 
 errout:
 	if (chain)
@@ -1790,6 +1821,10 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		/* Replay the request. */
 		goto replay;
 	return err;
+
+errout_locked:
+	mutex_unlock(&chain->filter_chain_lock);
+	goto errout;
 }
 
 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
@@ -1865,31 +1900,34 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		goto errout;
 	}
 
+	mutex_lock(&chain->filter_chain_lock);
 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 			       prio, false);
 	if (!tp || IS_ERR(tp)) {
 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
 		err = tp ? PTR_ERR(tp) : -ENOENT;
-		goto errout;
+		goto errout_locked;
 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
 		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
 		err = -EINVAL;
+		goto errout_locked;
+	} else if (t->tcm_handle == 0) {
+		tcf_chain_tp_remove(chain, &chain_info, tp);
+		mutex_unlock(&chain->filter_chain_lock);
+
+		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
+			       RTM_DELTFILTER, false);
+		tcf_proto_destroy(tp, extack);
+		err = 0;
 		goto errout;
 	}
+	mutex_unlock(&chain->filter_chain_lock);
 
 	fh = tp->ops->get(tp, t->tcm_handle);
 
 	if (!fh) {
-		if (t->tcm_handle == 0) {
-			tcf_chain_tp_remove(chain, &chain_info, tp);
-			tfilter_notify(net, skb, n, tp, block, q, parent, fh,
-				       RTM_DELTFILTER, false);
-			tcf_proto_destroy(tp, extack);
-			err = 0;
-		} else {
-			NL_SET_ERR_MSG(extack, "Specified filter handle not found");
-			err = -ENOENT;
-		}
+		NL_SET_ERR_MSG(extack, "Specified filter handle not found");
+		err = -ENOENT;
 	} else {
 		bool last;
 
@@ -1899,7 +1937,10 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		if (err)
 			goto errout;
 		if (last) {
+			mutex_lock(&chain->filter_chain_lock);
 			tcf_chain_tp_remove(chain, &chain_info, tp);
+			mutex_unlock(&chain->filter_chain_lock);
+
 			tcf_proto_destroy(tp, extack);
 		}
 	}
@@ -1909,6 +1950,10 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		tcf_chain_put(chain);
 	tcf_block_release(q, block);
 	return err;
+
+errout_locked:
+	mutex_unlock(&chain->filter_chain_lock);
+	goto errout;
 }
 
 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
@@ -1966,8 +2011,10 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		goto errout;
 	}
 
+	mutex_lock(&chain->filter_chain_lock);
 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 			       prio, false);
+	mutex_unlock(&chain->filter_chain_lock);
 	if (!tp || IS_ERR(tp)) {
 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
 		err = tp ? PTR_ERR(tp) : -ENOENT;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 66ba2ce2320f..e24568f9246c 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1366,7 +1366,11 @@ static void mini_qdisc_rcu_func(struct rcu_head *head)
 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
 			  struct tcf_proto *tp_head)
 {
-	struct mini_Qdisc *miniq_old = rtnl_dereference(*miniqp->p_miniq);
+	/* Protected with chain0->filter_chain_lock.
+	 * Can't access chain directly because tp_head can be NULL.
+	 */
+	struct mini_Qdisc *miniq_old =
+		rcu_dereference_protected(*miniqp->p_miniq, 1);
 	struct mini_Qdisc *miniq;
 
 	if (!tp_head) {
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 05/17] net: sched: traverse chains in block with tcf_get_next_chain()
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

All users of block->chain_list rely on rtnl lock and assume that no new
chains are added when traversing the list. Use tcf_get_next_chain() to
traverse chain list without relying on rtnl mutex. This function iterates
over chains by taking reference to current iterator chain only and doesn't
assume external synchronization of chain list.

Don't take reference to all chains in block when flushing and use
tcf_get_next_chain() to safely iterate over chain list instead. Remove
tcf_block_put_all_chains() that is no longer used.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/pkt_cls.h |  2 ++
 net/sched/cls_api.c   | 96 +++++++++++++++++++++++++++++++++++++--------------
 net/sched/sch_api.c   |  4 ++-
 3 files changed, 76 insertions(+), 26 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index cb8be396a11f..38bee7dd21d1 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -44,6 +44,8 @@ bool tcf_queue_work(struct rcu_work *rwork, work_func_t func);
 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block,
 				       u32 chain_index);
 void tcf_chain_put_by_act(struct tcf_chain *chain);
+struct tcf_chain *tcf_get_next_chain(struct tcf_block *block,
+				     struct tcf_chain *chain);
 void tcf_block_netif_keep_dst(struct tcf_block *block);
 int tcf_block_get(struct tcf_block **p_block,
 		  struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 869ae44d7631..8e2ac785f6fd 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -883,28 +883,62 @@ static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
 	return block;
 }
 
-static void tcf_block_flush_all_chains(struct tcf_block *block)
+static struct tcf_chain *
+__tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 {
-	struct tcf_chain *chain;
+	mutex_lock(&block->lock);
+	if (chain)
+		chain = list_is_last(&chain->list, &block->chain_list) ?
+			NULL : list_next_entry(chain, list);
+	else
+		chain = list_first_entry_or_null(&block->chain_list,
+						 struct tcf_chain, list);
 
-	/* Hold a refcnt for all chains, so that they don't disappear
-	 * while we are iterating.
-	 */
-	list_for_each_entry(chain, &block->chain_list, list)
+	/* skip all action-only chains */
+	while (chain && tcf_chain_held_by_acts_only(chain))
+		chain = list_is_last(&chain->list, &block->chain_list) ?
+			NULL : list_next_entry(chain, list);
+
+	if (chain)
 		tcf_chain_hold(chain);
+	mutex_unlock(&block->lock);
 
-	list_for_each_entry(chain, &block->chain_list, list)
-		tcf_chain_flush(chain);
+	return chain;
 }
 
-static void tcf_block_put_all_chains(struct tcf_block *block)
+/* Function to be used by all clients that want to iterate over all chains on
+ * block. It properly obtains block->lock and takes reference to chain before
+ * returning it. Users of this function must be tolerant to concurrent chain
+ * insertion/deletion or ensure that no concurrent chain modification is
+ * possible. Note that all netlink dump callbacks cannot guarantee to provide
+ * consistent dump because rtnl lock is released each time skb is filled with
+ * data and sent to user-space.
+ */
+
+struct tcf_chain *
+tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 {
-	struct tcf_chain *chain, *tmp;
+	struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
 
-	/* At this point, all the chains should have refcnt >= 1. */
-	list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
-		tcf_chain_put_explicitly_created(chain);
+	if (chain)
 		tcf_chain_put(chain);
+
+	return chain_next;
+}
+EXPORT_SYMBOL(tcf_get_next_chain);
+
+static void tcf_block_flush_all_chains(struct tcf_block *block)
+{
+	struct tcf_chain *chain;
+
+	/* Last reference to block. At this point chains cannot be added or
+	 * removed concurrently.
+	 */
+	for (chain = tcf_get_next_chain(block, NULL);
+	     chain;
+	     chain = tcf_get_next_chain(block, chain)) {
+		tcf_chain_put_explicitly_created(chain);
+		tcf_chain_flush(chain);
 	}
 }
 
@@ -923,8 +957,6 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 		mutex_unlock(&block->lock);
 		if (tcf_block_shared(block))
 			tcf_block_remove(block, block->net);
-		if (!free_block)
-			tcf_block_flush_all_chains(block);
 
 		if (q)
 			tcf_block_offload_unbind(block, q, ei);
@@ -932,7 +964,7 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 		if (free_block)
 			tcf_block_destroy(block);
 		else
-			tcf_block_put_all_chains(block);
+			tcf_block_flush_all_chains(block);
 	} else if (q) {
 		tcf_block_offload_unbind(block, q, ei);
 	}
@@ -1266,11 +1298,15 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 			    void *cb_priv, bool add, bool offload_in_use,
 			    struct netlink_ext_ack *extack)
 {
-	struct tcf_chain *chain;
+	struct tcf_chain *chain, *chain_prev;
 	struct tcf_proto *tp;
 	int err;
 
-	list_for_each_entry(chain, &block->chain_list, list) {
+	for (chain = __tcf_get_next_chain(block, NULL);
+	     chain;
+	     chain_prev = chain,
+		     chain = __tcf_get_next_chain(block, chain),
+		     tcf_chain_put(chain_prev)) {
 		for (tp = rtnl_dereference(chain->filter_chain); tp;
 		     tp = rtnl_dereference(tp->next)) {
 			if (tp->ops->reoffload) {
@@ -1289,6 +1325,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 	return 0;
 
 err_playback_remove:
+	tcf_chain_put(chain);
 	tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
 				    extack);
 	return err;
@@ -2023,11 +2060,11 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 /* called with RTNL */
 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct tcf_chain *chain, *chain_prev;
 	struct net *net = sock_net(skb->sk);
 	struct nlattr *tca[TCA_MAX + 1];
 	struct Qdisc *q = NULL;
 	struct tcf_block *block;
-	struct tcf_chain *chain;
 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
 	long index_start;
 	long index;
@@ -2091,12 +2128,17 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	index_start = cb->args[0];
 	index = 0;
 
-	list_for_each_entry(chain, &block->chain_list, list) {
+	for (chain = __tcf_get_next_chain(block, NULL);
+	     chain;
+	     chain_prev = chain,
+		     chain = __tcf_get_next_chain(block, chain),
+		     tcf_chain_put(chain_prev)) {
 		if (tca[TCA_CHAIN] &&
 		    nla_get_u32(tca[TCA_CHAIN]) != chain->index)
 			continue;
 		if (!tcf_chain_dump(chain, q, parent, skb, cb,
 				    index_start, &index)) {
+			tcf_chain_put(chain);
 			err = -EMSGSIZE;
 			break;
 		}
@@ -2364,11 +2406,11 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
 /* called with RTNL */
 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct tcf_chain *chain, *chain_prev;
 	struct net *net = sock_net(skb->sk);
 	struct nlattr *tca[TCA_MAX + 1];
 	struct Qdisc *q = NULL;
 	struct tcf_block *block;
-	struct tcf_chain *chain;
 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
 	long index_start;
 	long index;
@@ -2432,7 +2474,11 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 	index_start = cb->args[0];
 	index = 0;
 
-	list_for_each_entry(chain, &block->chain_list, list) {
+	for (chain = __tcf_get_next_chain(block, NULL);
+	     chain;
+	     chain_prev = chain,
+		     chain = __tcf_get_next_chain(block, chain),
+		     tcf_chain_put(chain_prev)) {
 		if ((tca[TCA_CHAIN] &&
 		     nla_get_u32(tca[TCA_CHAIN]) != chain->index))
 			continue;
@@ -2440,14 +2486,14 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 			index++;
 			continue;
 		}
-		if (tcf_chain_held_by_acts_only(chain))
-			continue;
 		err = tc_chain_fill_node(chain, net, skb, block,
 					 NETLINK_CB(cb->skb).portid,
 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					 RTM_NEWCHAIN);
-		if (err <= 0)
+		if (err <= 0) {
+			tcf_chain_put(chain);
 			break;
+		}
 		index++;
 	}
 
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 03e26e8d0ec9..80058abc729f 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1909,7 +1909,9 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
 	block = cops->tcf_block(q, cl, NULL);
 	if (!block)
 		return;
-	list_for_each_entry(chain, &block->chain_list, list) {
+	for (chain = tcf_get_next_chain(block, NULL);
+	     chain;
+	     chain = tcf_get_next_chain(block, chain)) {
 		struct tcf_proto *tp;
 
 		for (tp = rtnl_dereference(chain->filter_chain);
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 00/17] Refactor classifier API to work with chain/classifiers without rtnl lock
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov

Currently, all netlink protocol handlers for updating rules, actions and
qdiscs are protected with single global rtnl lock which removes any
possibility for parallelism. This patch set is a third step to remove
rtnl lock dependency from TC rules update path.

Recently, new rtnl registration flag RTNL_FLAG_DOIT_UNLOCKED was added.
Handlers registered with this flag are called without RTNL taken. End
goal is to have rule update handlers(RTM_NEWTFILTER, RTM_DELTFILTER,
etc.) to be registered with UNLOCKED flag to allow parallel execution.
However, there is no intention to completely remove or split rtnl lock
itself. This patch set addresses specific problems in implementation of
classifiers API that prevent its control path from being executed
concurrently, and completes refactoring of cls API rules update handlers
by removing rtnl lock dependency from code that handles chains and
classifiers. Rules update handlers are registered with
RTNL_FLAG_DOIT_UNLOCKED flag.

This patch set substitutes global rtnl lock dependency on rules update
path in cls API by extending its data structures with following locks:
- tcf_block with 'lock' mutex. It is used to protect block state and
  life-time management fields of chains on the block (chain->refcnt,
  chain->action_refcnt, chain->explicitly crated, etc.).
- tcf_chain with 'filter_chain_lock' mutex, that is used to protect list
  of classifier instances attached to chain. chain0->filter_chain_lock
  serializes calls to head change callbacks and allows them to rely on
  filter_chain_lock for serialization instead of rtnl lock.
- tcf_proto with 'lock' spinlock that is intended to be used to
  synchronize access to classifiers that support unlocked execution.

Classifiers are extended with reference counting to accommodate parallel
access by unlocked cls API. Classifier ops structure is extended with
additional 'put' function to allow reference counting of filters and
intended to be used by classifiers that implement rtnl-unlocked API.
Users of classifiers and individual filter instances are modified to
always hold reference while working with them.

Classifiers that support unlocked execution still need to know the
status of rtnl lock, so their API is extended with additional
'rtnl_held' argument that is used to indicate that caller holds rtnl
lock. Cls API propagates rtnl lock status across its helper functions
and passes it to classifier.

Changes from V3 to V4:
- Patch 1:
  - Extract code that manages chain 'explicitly_created' flag into
    standalone patch.
- Patch 2 - new.

Changes from V2 to V3:
- Change block->lock and chain->filter_chain_lock type to mutex. This
  removes the need for async miniqp refactoring and allows calling
  sleeping functions while holding the block->lock and
  chain->filter_chain_lock locks.
- Previous patch 1 - async miniqp is no longer needed, remove the patch.
- Patch 1:
  - Change block->lock type to mutex.
  - Implement tcf_block_destroy() helper function that destroys
    block->lock mutex before deallocating the block.
  - Revert GFP_KERNEL->GFP_ATOMIC memory allocation flags of tcf_chain
    which is no longer needed after block->lock type change.
- Patch 6:
  - Change chain->filter_chain_lock type to mutex.
  - Assume chain0->filter_chain_lock synchronizations instead of rtnl
    lock in mini_qdisc_pair_swap() function that is called from head
    change callback of ingress Qdisc. With filter_chain_lock type
    changed to mutex it is now possible to call sleeping function while
    holding it, so it is now used instead of async implementation from
    previous versions of this patch set.
- Patch 7:
  - Add local tp_next var to tcf_chain_flush() and use it to store
    tp->next pointer dereferenced with rcu_dereference_protected() to
    satisfy kbuild test robot.
  - Reset tp pointer to NULL at the beginning of tc_new_tfilter() to
    prevent its uninitialized usage in error handling code. This code
    was already implemented in patch 10, but must be in patch 8 to
    preserve code bisectability.
  - Put parent chain in tcf_proto_destroy(). In previous version this
    code was implemented in patch 1 which was removed in V3.

Changes from V1 to V2:
- Patch 1:
  - Use smp_store_release() instead of xchg() for setting
    miniqp->tp_head.
  - Move Qdisc deallocation to tc_proto_wq ordered workqueue that is
    used to destroy tcf proto instances. This is necessary to ensure
    that Qdisc is destroyed after all instances of chain/proto that it
    contains in order to prevent use-after-free error in
    tc_chain_notify_delete().
  - Cache parent net device ifindex in block to prevent use-after-free
    of dev queue in tc_chain_notify_delete().
- Patch 2:
  - Use lockdep_assert_held() instead of spin_is_locked() for assertion.
  - Use 'free_block' argument in tcf_chain_destroy() instead of checking
    block's reference count and chain_list for second time.
- Patch 7:
  - Refactor tcf_chain0_head_change_cb_add() to not take block->lock and
    chain0->filter_chain_lock in correct order.
- Patch 10:
  - Always set 'tp_created' flag when creating tp to prevent releasing
    the chain twice when tp with same priority was inserted
    concurrently.
- Patch 11:
  - Add additional check to prevent creation of new proto instance when
    parent chain is being flushed to reduce CPU usage.
  - Don't call tcf_chain_delete_empty() if tp insertion failed.
- Patch 16 - new.
- Patch 17:
  - Refactor to only lock take rtnl lock once (at the beginning of rule
    update handlers).
  - Always release rtnl mutex in the same function that locked it.
    Remove unlock code from tcf_block_release().

Github:
[https://github.com/vbuslov/linux/tree/cls_api_rtnl_lock_remove_for_cong_v4]

Vlad Buslov (17):
  net: sched: protect block state with mutex
  net: sched: protect chain->explicitly_created with block->lock
  net: sched: refactor tc_ctl_chain() to use block->lock
  net: sched: protect block->chain0 with block->lock
  net: sched: traverse chains in block with tcf_get_next_chain()
  net: sched: protect chain template accesses with block lock
  net: sched: protect filter_chain list with filter_chain_lock mutex
  net: sched: introduce reference counting for tcf_proto
  net: sched: traverse classifiers in chain with tcf_get_next_proto()
  net: sched: refactor tp insert/delete for concurrent execution
  net: sched: prevent insertion of new classifiers during chain flush
  net: sched: track rtnl lock status when validating extensions
  net: sched: extend proto ops with 'put' callback
  net: sched: extend proto ops to support unlocked classifiers
  net: sched: add flags to Qdisc class ops struct
  net: sched: refactor tcf_block_find() into standalone functions
  net: sched: unlock rules update API

 include/net/pkt_cls.h     |    6 +-
 include/net/sch_generic.h |   68 ++-
 net/sched/cls_api.c       | 1214 ++++++++++++++++++++++++++++++++++-----------
 net/sched/cls_basic.c     |   14 +-
 net/sched/cls_bpf.c       |   15 +-
 net/sched/cls_cgroup.c    |   13 +-
 net/sched/cls_flow.c      |   15 +-
 net/sched/cls_flower.c    |   16 +-
 net/sched/cls_fw.c        |   15 +-
 net/sched/cls_matchall.c  |   16 +-
 net/sched/cls_route.c     |   14 +-
 net/sched/cls_rsvp.h      |   16 +-
 net/sched/cls_tcindex.c   |   17 +-
 net/sched/cls_u32.c       |   14 +-
 net/sched/sch_api.c       |   10 +-
 net/sched/sch_generic.c   |    6 +-
 16 files changed, 1103 insertions(+), 366 deletions(-)

-- 
2.13.6


^ permalink raw reply

* [PATCH net-next v4 06/17] net: sched: protect chain template accesses with block lock
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

When cls API is called without protection of rtnl lock, parallel
modification of chain is possible, which means that chain template can be
changed concurrently in certain circumstances. For example, when chain is
'deleted' by new user-space chain API, the chain might continue to be used
if it is referenced by actions, and can be 're-created' again by user. In
such case same chain structure is reused and its template is changed. To
protect from described scenario, cache chain template while holding block
lock. Introduce standalone tc_chain_notify_delete() function that works
with cached template values, instead of chains themselves.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 net/sched/cls_api.c | 73 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 16 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8e2ac785f6fd..0dcce8b0c7b4 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -371,14 +371,22 @@ struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
 }
 EXPORT_SYMBOL(tcf_chain_get_by_act);
 
-static void tc_chain_tmplt_del(struct tcf_chain *chain);
+static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
+			       void *tmplt_priv);
+static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
+				  void *tmplt_priv, u32 chain_index,
+				  struct tcf_block *block, struct sk_buff *oskb,
+				  u32 seq, u16 flags, bool unicast);
 
 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 			    bool explicitly_created)
 {
 	struct tcf_block *block = chain->block;
+	const struct tcf_proto_ops *tmplt_ops;
 	bool is_last, free_block = false;
 	unsigned int refcnt;
+	void *tmplt_priv;
+	u32 chain_index;
 
 	mutex_lock(&block->lock);
 	if (explicitly_created) {
@@ -398,16 +406,21 @@ static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
 	 */
 	refcnt = --chain->refcnt;
 	is_last = refcnt - chain->action_refcnt == 0;
+	tmplt_ops = chain->tmplt_ops;
+	tmplt_priv = chain->tmplt_priv;
+	chain_index = chain->index;
+
 	if (refcnt == 0)
 		free_block = tcf_chain_detach(chain);
 	mutex_unlock(&block->lock);
 
 	/* The last dropped non-action reference will trigger notification. */
 	if (is_last && !by_act)
-		tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false);
+		tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain_index,
+				       block, NULL, 0, 0, false);
 
 	if (refcnt == 0) {
-		tc_chain_tmplt_del(chain);
+		tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
 		tcf_chain_destroy(chain, free_block);
 	}
 }
@@ -2155,8 +2168,10 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
-static int tc_chain_fill_node(struct tcf_chain *chain, struct net *net,
-			      struct sk_buff *skb, struct tcf_block *block,
+static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
+			      void *tmplt_priv, u32 chain_index,
+			      struct net *net, struct sk_buff *skb,
+			      struct tcf_block *block,
 			      u32 portid, u32 seq, u16 flags, int event)
 {
 	unsigned char *b = skb_tail_pointer(skb);
@@ -2165,8 +2180,8 @@ static int tc_chain_fill_node(struct tcf_chain *chain, struct net *net,
 	struct tcmsg *tcm;
 	void *priv;
 
-	ops = chain->tmplt_ops;
-	priv = chain->tmplt_priv;
+	ops = tmplt_ops;
+	priv = tmplt_priv;
 
 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
 	if (!nlh)
@@ -2184,7 +2199,7 @@ static int tc_chain_fill_node(struct tcf_chain *chain, struct net *net,
 		tcm->tcm_block_index = block->index;
 	}
 
-	if (nla_put_u32(skb, TCA_CHAIN, chain->index))
+	if (nla_put_u32(skb, TCA_CHAIN, chain_index))
 		goto nla_put_failure;
 
 	if (ops) {
@@ -2215,7 +2230,8 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 	if (!skb)
 		return -ENOBUFS;
 
-	if (tc_chain_fill_node(chain, net, skb, block, portid,
+	if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
+			       chain->index, net, skb, block, portid,
 			       seq, flags, event) <= 0) {
 		kfree_skb(skb);
 		return -EINVAL;
@@ -2227,6 +2243,31 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
 }
 
+static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
+				  void *tmplt_priv, u32 chain_index,
+				  struct tcf_block *block, struct sk_buff *oskb,
+				  u32 seq, u16 flags, bool unicast)
+{
+	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
+	struct net *net = block->net;
+	struct sk_buff *skb;
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
+			       block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	if (unicast)
+		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+
+	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
+}
+
 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 			      struct nlattr **tca,
 			      struct netlink_ext_ack *extack)
@@ -2256,16 +2297,15 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 	return 0;
 }
 
-static void tc_chain_tmplt_del(struct tcf_chain *chain)
+static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
+			       void *tmplt_priv)
 {
-	const struct tcf_proto_ops *ops = chain->tmplt_ops;
-
 	/* If template ops are set, no work to do for us. */
-	if (!ops)
+	if (!tmplt_ops)
 		return;
 
-	ops->tmplt_destroy(chain->tmplt_priv);
-	module_put(ops->owner);
+	tmplt_ops->tmplt_destroy(tmplt_priv);
+	module_put(tmplt_ops->owner);
 }
 
 /* Add/delete/get a chain */
@@ -2486,7 +2526,8 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 			index++;
 			continue;
 		}
-		err = tc_chain_fill_node(chain, net, skb, block,
+		err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
+					 chain->index, net, skb, block,
 					 NETLINK_CB(cb->skb).portid,
 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					 RTM_NEWCHAIN);
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 15/17] net: sched: add flags to Qdisc class ops struct
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Extend Qdisc_class_ops with flags. Create enum to hold possible class ops
flag values. Add first class ops flags value QDISC_CLASS_OPS_DOIT_UNLOCKED
to indicate that class ops functions can be called without taking rtnl
lock.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/sch_generic.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 365801c2a4f5..e50b729f8691 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -179,6 +179,7 @@ static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
 }
 
 struct Qdisc_class_ops {
+	unsigned int		flags;
 	/* Child qdisc manipulation */
 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
 	int			(*graft)(struct Qdisc *, unsigned long cl,
@@ -210,6 +211,13 @@ struct Qdisc_class_ops {
 					struct gnet_dump *);
 };
 
+/* Qdisc_class_ops flag values */
+
+/* Implements API that doesn't require rtnl lock */
+enum qdisc_class_ops_flags {
+	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
+};
+
 struct Qdisc_ops {
 	struct Qdisc_ops	*next;
 	const struct Qdisc_class_ops	*cl_ops;
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 12/17] net: sched: track rtnl lock status when validating extensions
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Actions API is already updated to not rely on rtnl lock for
synchronization. However, it need to be provided with rtnl status when
called from classifiers API in order to be able to correctly release the
lock when loading kernel module.

Extend extension validation function with 'rtnl_held' flag which is passed
to actions API. Add new 'rtnl_held' parameter to tcf_exts_validate() in cls
API. No classifier is currently updated to support unlocked execution, so
pass hardcoded 'true' flag parameter value.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/pkt_cls.h    | 2 +-
 net/sched/cls_api.c      | 9 +++++----
 net/sched/cls_basic.c    | 2 +-
 net/sched/cls_bpf.c      | 3 ++-
 net/sched/cls_cgroup.c   | 2 +-
 net/sched/cls_flow.c     | 2 +-
 net/sched/cls_flower.c   | 3 ++-
 net/sched/cls_fw.c       | 2 +-
 net/sched/cls_matchall.c | 3 ++-
 net/sched/cls_route.c    | 2 +-
 net/sched/cls_rsvp.h     | 3 ++-
 net/sched/cls_tcindex.c  | 2 +-
 net/sched/cls_u32.c      | 2 +-
 13 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index e5dafa5ee1b2..0e3b61016931 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -416,7 +416,7 @@ tcf_exts_exec(struct sk_buff *skb, struct tcf_exts *exts,
 
 int tcf_exts_validate(struct net *net, struct tcf_proto *tp,
 		      struct nlattr **tb, struct nlattr *rate_tlv,
-		      struct tcf_exts *exts, bool ovr,
+		      struct tcf_exts *exts, bool ovr, bool rtnl_held,
 		      struct netlink_ext_ack *extack);
 void tcf_exts_destroy(struct tcf_exts *exts);
 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 3038a82f6591..a3e715d34efb 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2841,7 +2841,7 @@ EXPORT_SYMBOL(tcf_exts_destroy);
 
 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
-		      struct netlink_ext_ack *extack)
+		      bool rtnl_held, struct netlink_ext_ack *extack)
 {
 #ifdef CONFIG_NET_CLS_ACT
 	{
@@ -2851,7 +2851,8 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 		if (exts->police && tb[exts->police]) {
 			act = tcf_action_init_1(net, tp, tb[exts->police],
 						rate_tlv, "police", ovr,
-						TCA_ACT_BIND, true, extack);
+						TCA_ACT_BIND, rtnl_held,
+						extack);
 			if (IS_ERR(act))
 				return PTR_ERR(act);
 
@@ -2863,8 +2864,8 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 
 			err = tcf_action_init(net, tp, tb[exts->action],
 					      rate_tlv, NULL, ovr, TCA_ACT_BIND,
-					      exts->actions, &attr_size, true,
-					      extack);
+					      exts->actions, &attr_size,
+					      rtnl_held, extack);
 			if (err < 0)
 				return err;
 			exts->nr_actions = err;
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index 4a57fec6f306..eaf9c02fe792 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -153,7 +153,7 @@ static int basic_set_parms(struct net *net, struct tcf_proto *tp,
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true, extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index a95cb240a606..656b3423ad35 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -417,7 +417,8 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 		return -EINVAL;
 
-	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, extack);
+	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, true,
+				extack);
 	if (ret < 0)
 		return ret;
 
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 3bc01bdde165..663ee1c6d606 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -110,7 +110,7 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 		goto errout;
 
 	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr,
-				extack);
+				true, extack);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 2bb043cd436b..39a6407d4832 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -445,7 +445,7 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 		goto err2;
 
 	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr,
-				extack);
+				true, extack);
 	if (err < 0)
 		goto err2;
 
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index c5d1db3a3db7..d187bda602fa 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1272,7 +1272,8 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true,
+				extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 29eeeaf3ea44..c8173ebb69f2 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -217,7 +217,7 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 	int err;
 
 	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, ovr,
-				extack);
+				true, extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index a1b803fd372e..8848a147c4bf 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -145,7 +145,8 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, true,
+				extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 0404aa5fa7cb..44b26038c4c4 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -393,7 +393,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 	struct route4_bucket *b;
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true, extack);
 	if (err < 0)
 		return err;
 
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index e9ccf7daea7d..9dd9530e6a52 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -502,7 +502,8 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 	err = tcf_exts_init(&e, TCA_RSVP_ACT, TCA_RSVP_POLICE);
 	if (err < 0)
 		return err;
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr, true,
+				extack);
 	if (err < 0)
 		goto errout2;
 
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 9ccc93f257db..b7dc667b6ec0 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -314,7 +314,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	err = tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 	if (err < 0)
 		return err;
-	err = tcf_exts_validate(net, tp, tb, est, &e, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &e, ovr, true, extack);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index dcea21004604..e891f30d42e9 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -726,7 +726,7 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr, extack);
+	err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr, true, extack);
 	if (err < 0)
 		return err;
 
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 17/17] net: sched: unlock rules update API
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

Register netlink protocol handlers for message types RTM_NEWTFILTER,
RTM_DELTFILTER, RTM_GETTFILTER as unlocked. Set rtnl_held variable that
tracks rtnl mutex state to be false by default.

Introduce tcf_proto_is_unlocked() helper that is used to check
tcf_proto_ops->flag to determine if ops can be called without taking rtnl
lock. Manually lookup Qdisc, class and block in rule update handlers.
Verify that both Qdisc ops and proto ops are unlocked before using any of
their callbacks, and obtain rtnl lock otherwise.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 net/sched/cls_api.c | 131 +++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 114 insertions(+), 17 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 5f9373ee47ce..266fcb34fefe 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -163,6 +163,23 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 	return TC_H_MAJ(first);
 }
 
+static bool tcf_proto_is_unlocked(const char *kind)
+{
+	const struct tcf_proto_ops *ops;
+	bool ret;
+
+	ops = tcf_proto_lookup_ops(kind, false, NULL);
+	/* On error return false to take rtnl lock. Proto lookup/create
+	 * functions will perform lookup again and properly handle errors.
+	 */
+	if (IS_ERR(ops))
+		return false;
+
+	ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
+	module_put(ops->owner);
+	return ret;
+}
+
 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 					  u32 prio, struct tcf_chain *chain,
 					  bool rtnl_held,
@@ -1312,8 +1329,12 @@ static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
 	if (!IS_ERR_OR_NULL(block))
 		tcf_block_refcnt_put(block, rtnl_held);
 
-	if (q)
-		qdisc_put(q);
+	if (q) {
+		if (rtnl_held)
+			qdisc_put(q);
+		else
+			qdisc_put_unlocked(q);
+	}
 }
 
 struct tcf_block_owner_item {
@@ -1966,7 +1987,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	void *fh;
 	int err;
 	int tp_created;
-	bool rtnl_held = true;
+	bool rtnl_held = false;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -1985,6 +2006,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	parent = t->tcm_parent;
 	tp = NULL;
 	cl = 0;
+	block = NULL;
 
 	if (prio == 0) {
 		/* If no priority is provided by the user,
@@ -2001,8 +2023,27 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	/* Find head of filter chain. */
 
-	block = tcf_block_find(net, &q, &parent, &cl,
-			       t->tcm_ifindex, t->tcm_block_index, extack);
+	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+	if (err)
+		return err;
+
+	/* Take rtnl mutex if rtnl_held was set to true on previous iteration,
+	 * block is shared (no qdisc found), qdisc is not unlocked, classifier
+	 * type is not specified, classifier is not unlocked.
+	 */
+	if (rtnl_held ||
+	    (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+		rtnl_held = true;
+		rtnl_lock();
+	}
+
+	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+	if (err)
+		goto errout;
+
+	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+				 extack);
 	if (IS_ERR(block)) {
 		err = PTR_ERR(block);
 		goto errout;
@@ -2123,9 +2164,18 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 			tcf_chain_put(chain);
 	}
 	tcf_block_release(q, block, rtnl_held);
-	if (err == -EAGAIN)
+
+	if (rtnl_held)
+		rtnl_unlock();
+
+	if (err == -EAGAIN) {
+		/* Take rtnl lock in case EAGAIN is caused by concurrent flush
+		 * of target chain.
+		 */
+		rtnl_held = true;
 		/* Replay the request. */
 		goto replay;
+	}
 	return err;
 
 errout_locked:
@@ -2146,12 +2196,12 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	struct Qdisc *q = NULL;
 	struct tcf_chain_info chain_info;
 	struct tcf_chain *chain = NULL;
-	struct tcf_block *block;
+	struct tcf_block *block = NULL;
 	struct tcf_proto *tp = NULL;
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
-	bool rtnl_held = true;
+	bool rtnl_held = false;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -2172,8 +2222,27 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	/* Find head of filter chain. */
 
-	block = tcf_block_find(net, &q, &parent, &cl,
-			       t->tcm_ifindex, t->tcm_block_index, extack);
+	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+	if (err)
+		return err;
+
+	/* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
+	 * found), qdisc is not unlocked, classifier type is not specified,
+	 * classifier is not unlocked.
+	 */
+	if (!prio ||
+	    (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+		rtnl_held = true;
+		rtnl_lock();
+	}
+
+	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+	if (err)
+		goto errout;
+
+	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+				 extack);
 	if (IS_ERR(block)) {
 		err = PTR_ERR(block);
 		goto errout;
@@ -2255,6 +2324,10 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		tcf_chain_put(chain);
 	}
 	tcf_block_release(q, block, rtnl_held);
+
+	if (rtnl_held)
+		rtnl_unlock();
+
 	return err;
 
 errout_locked:
@@ -2275,12 +2348,12 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	struct Qdisc *q = NULL;
 	struct tcf_chain_info chain_info;
 	struct tcf_chain *chain = NULL;
-	struct tcf_block *block;
+	struct tcf_block *block = NULL;
 	struct tcf_proto *tp = NULL;
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
-	bool rtnl_held = true;
+	bool rtnl_held = false;
 
 	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
 	if (err < 0)
@@ -2298,8 +2371,26 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	/* Find head of filter chain. */
 
-	block = tcf_block_find(net, &q, &parent, &cl,
-			       t->tcm_ifindex, t->tcm_block_index, extack);
+	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+	if (err)
+		return err;
+
+	/* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
+	 * unlocked, classifier type is not specified, classifier is not
+	 * unlocked.
+	 */
+	if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+		rtnl_held = true;
+		rtnl_lock();
+	}
+
+	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+	if (err)
+		goto errout;
+
+	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+				 extack);
 	if (IS_ERR(block)) {
 		err = PTR_ERR(block);
 		goto errout;
@@ -2352,6 +2443,10 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		tcf_chain_put(chain);
 	}
 	tcf_block_release(q, block, rtnl_held);
+
+	if (rtnl_held)
+		rtnl_unlock();
+
 	return err;
 }
 
@@ -3214,10 +3309,12 @@ static int __init tc_filter_init(void)
 	if (err)
 		goto err_rhash_setup_block_ht;
 
-	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, 0);
-	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0);
+	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
+		      RTNL_FLAG_DOIT_UNLOCKED);
+	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
+		      RTNL_FLAG_DOIT_UNLOCKED);
 	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
-		      tc_dump_tfilter, 0);
+		      tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
 	rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 09/17] net: sched: traverse classifiers in chain with tcf_get_next_proto()
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

All users of chain->filters_chain rely on rtnl lock and assume that no new
classifier instances are added when traversing the list. Use
tcf_get_next_proto() to traverse filters list without relying on rtnl
mutex. This function iterates over classifiers by taking reference to
current iterator classifier only and doesn't assume external
synchronization of filters list.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/pkt_cls.h |  2 ++
 net/sched/cls_api.c   | 70 +++++++++++++++++++++++++++++++++++++++++++--------
 net/sched/sch_api.c   |  4 +--
 3 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 38bee7dd21d1..e5dafa5ee1b2 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -46,6 +46,8 @@ struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block,
 void tcf_chain_put_by_act(struct tcf_chain *chain);
 struct tcf_chain *tcf_get_next_chain(struct tcf_block *block,
 				     struct tcf_chain *chain);
+struct tcf_proto *tcf_get_next_proto(struct tcf_chain *chain,
+				     struct tcf_proto *tp);
 void tcf_block_netif_keep_dst(struct tcf_block *block);
 int tcf_block_get(struct tcf_block **p_block,
 		  struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 37c05b96898f..dca8a3bee9c2 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -980,6 +980,45 @@ tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
 }
 EXPORT_SYMBOL(tcf_get_next_chain);
 
+static struct tcf_proto *
+__tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+{
+	ASSERT_RTNL();
+	mutex_lock(&chain->filter_chain_lock);
+
+	if (!tp)
+		tp = tcf_chain_dereference(chain->filter_chain, chain);
+	else
+		tp = tcf_chain_dereference(tp->next, chain);
+
+	if (tp)
+		tcf_proto_get(tp);
+
+	mutex_unlock(&chain->filter_chain_lock);
+
+	return tp;
+}
+
+/* Function to be used by all clients that want to iterate over all tp's on
+ * chain. Users of this function must be tolerant to concurrent tp
+ * insertion/deletion or ensure that no concurrent chain modification is
+ * possible. Note that all netlink dump callbacks cannot guarantee to provide
+ * consistent dump because rtnl lock is released each time skb is filled with
+ * data and sent to user-space.
+ */
+
+struct tcf_proto *
+tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+{
+	struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
+
+	if (tp)
+		tcf_proto_put(tp, NULL);
+
+	return tp_next;
+}
+EXPORT_SYMBOL(tcf_get_next_proto);
+
 static void tcf_block_flush_all_chains(struct tcf_block *block)
 {
 	struct tcf_chain *chain;
@@ -1352,7 +1391,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 			    struct netlink_ext_ack *extack)
 {
 	struct tcf_chain *chain, *chain_prev;
-	struct tcf_proto *tp;
+	struct tcf_proto *tp, *tp_prev;
 	int err;
 
 	for (chain = __tcf_get_next_chain(block, NULL);
@@ -1360,8 +1399,10 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 	     chain_prev = chain,
 		     chain = __tcf_get_next_chain(block, chain),
 		     tcf_chain_put(chain_prev)) {
-		for (tp = rtnl_dereference(chain->filter_chain); tp;
-		     tp = rtnl_dereference(tp->next)) {
+		for (tp = __tcf_get_next_proto(chain, NULL); tp;
+		     tp_prev = tp,
+			     tp = __tcf_get_next_proto(chain, tp),
+			     tcf_proto_put(tp_prev, NULL)) {
 			if (tp->ops->reoffload) {
 				err = tp->ops->reoffload(tp, add, cb, cb_priv,
 							 extack);
@@ -1378,6 +1419,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 	return 0;
 
 err_playback_remove:
+	tcf_proto_put(tp, NULL);
 	tcf_chain_put(chain);
 	tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
 				    extack);
@@ -1677,8 +1719,8 @@ static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 {
 	struct tcf_proto *tp;
 
-	for (tp = rtnl_dereference(chain->filter_chain);
-	     tp; tp = rtnl_dereference(tp->next))
+	for (tp = tcf_get_next_proto(chain, NULL);
+	     tp; tp = tcf_get_next_proto(chain, tp))
 		tfilter_notify(net, oskb, n, tp, block,
 			       q, parent, NULL, event, false);
 }
@@ -2104,11 +2146,15 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 	struct net *net = sock_net(skb->sk);
 	struct tcf_block *block = chain->block;
 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
+	struct tcf_proto *tp, *tp_prev;
 	struct tcf_dump_args arg;
-	struct tcf_proto *tp;
 
-	for (tp = rtnl_dereference(chain->filter_chain);
-	     tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
+	for (tp = __tcf_get_next_proto(chain, NULL);
+	     tp;
+	     tp_prev = tp,
+		     tp = __tcf_get_next_proto(chain, tp),
+		     tcf_proto_put(tp_prev, NULL),
+		     (*p_index)++) {
 		if (*p_index < index_start)
 			continue;
 		if (TC_H_MAJ(tcm->tcm_info) &&
@@ -2125,7 +2171,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 					  NETLINK_CB(cb->skb).portid,
 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					  RTM_NEWTFILTER) <= 0)
-				return false;
+				goto errout;
 
 			cb->args[1] = 1;
 		}
@@ -2145,9 +2191,13 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 		cb->args[2] = arg.w.cookie;
 		cb->args[1] = arg.w.count + 1;
 		if (arg.w.stop)
-			return false;
+			goto errout;
 	}
 	return true;
+
+errout:
+	tcf_proto_put(tp, NULL);
+	return false;
 }
 
 /* called with RTNL */
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 80058abc729f..9a530cad2759 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1914,8 +1914,8 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
 	     chain = tcf_get_next_chain(block, chain)) {
 		struct tcf_proto *tp;
 
-		for (tp = rtnl_dereference(chain->filter_chain);
-		     tp; tp = rtnl_dereference(tp->next)) {
+		for (tp = tcf_get_next_proto(chain, NULL);
+		     tp; tp = tcf_get_next_proto(chain, tp)) {
 			struct tcf_bind_args arg = {};
 
 			arg.w.fn = tcf_node_bind;
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 04/17] net: sched: protect block->chain0 with block->lock
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

In order to remove dependency on rtnl lock, use block->lock to protect
chain0 struct from concurrent modification. Rearrange code in chain0
callback add and del functions to only access chain0 when block->lock is
held.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 net/sched/cls_api.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index b5db0f79db14..869ae44d7631 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -244,8 +244,11 @@ static void tcf_chain0_head_change(struct tcf_chain *chain,
 
 	if (chain->index)
 		return;
+
+	mutex_lock(&block->lock);
 	list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 		tcf_chain_head_change_item(item, tp_head);
+	mutex_unlock(&block->lock);
 }
 
 /* Returns true if block can be safely freed. */
@@ -756,8 +759,8 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
 			      struct tcf_block_ext_info *ei,
 			      struct netlink_ext_ack *extack)
 {
-	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
+	struct tcf_chain *chain0;
 
 	item = kmalloc(sizeof(*item), GFP_KERNEL);
 	if (!item) {
@@ -766,9 +769,14 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
 	}
 	item->chain_head_change = ei->chain_head_change;
 	item->chain_head_change_priv = ei->chain_head_change_priv;
+
+	mutex_lock(&block->lock);
+	chain0 = block->chain0.chain;
 	if (chain0 && chain0->filter_chain)
 		tcf_chain_head_change_item(item, chain0->filter_chain);
 	list_add(&item->list, &block->chain0.filter_chain_list);
+	mutex_unlock(&block->lock);
+
 	return 0;
 }
 
@@ -776,20 +784,23 @@ static void
 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 			      struct tcf_block_ext_info *ei)
 {
-	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
 
+	mutex_lock(&block->lock);
 	list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 		if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 		    (item->chain_head_change == ei->chain_head_change &&
 		     item->chain_head_change_priv == ei->chain_head_change_priv)) {
-			if (chain0)
+			if (block->chain0.chain)
 				tcf_chain_head_change_item(item, NULL);
 			list_del(&item->list);
+			mutex_unlock(&block->lock);
+
 			kfree(item);
 			return;
 		}
 	}
+	mutex_unlock(&block->lock);
 	WARN_ON(1);
 }
 
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 02/17] net: sched: protect chain->explicitly_created with block->lock
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

In order to remove dependency on rtnl lock, protect
tcf_chain->explicitly_created flag with block->lock. Consolidate code that
checks and resets 'explicitly_created' flag into __tcf_chain_put() to
execute it atomically with rest of code that puts chain reference.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
---
 net/sched/cls_api.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 806e7158a7e8..2ebf8e53038a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -370,13 +370,22 @@ EXPORT_SYMBOL(tcf_chain_get_by_act);
 
 static void tc_chain_tmplt_del(struct tcf_chain *chain);
 
-static void __tcf_chain_put(struct tcf_chain *chain, bool by_act)
+static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
+			    bool explicitly_created)
 {
 	struct tcf_block *block = chain->block;
 	bool is_last, free_block = false;
 	unsigned int refcnt;
 
 	mutex_lock(&block->lock);
+	if (explicitly_created) {
+		if (!chain->explicitly_created) {
+			mutex_unlock(&block->lock);
+			return;
+		}
+		chain->explicitly_created = false;
+	}
+
 	if (by_act)
 		chain->action_refcnt--;
 
@@ -402,19 +411,18 @@ static void __tcf_chain_put(struct tcf_chain *chain, bool by_act)
 
 static void tcf_chain_put(struct tcf_chain *chain)
 {
-	__tcf_chain_put(chain, false);
+	__tcf_chain_put(chain, false, false);
 }
 
 void tcf_chain_put_by_act(struct tcf_chain *chain)
 {
-	__tcf_chain_put(chain, true);
+	__tcf_chain_put(chain, true, false);
 }
 EXPORT_SYMBOL(tcf_chain_put_by_act);
 
 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 {
-	if (chain->explicitly_created)
-		tcf_chain_put(chain);
+	__tcf_chain_put(chain, false, true);
 }
 
 static void tcf_chain_flush(struct tcf_chain *chain)
@@ -2305,7 +2313,6 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
 		 * to the chain previously taken during addition.
 		 */
 		tcf_chain_put_explicitly_created(chain);
-		chain->explicitly_created = false;
 		break;
 	case RTM_GETCHAIN:
 		err = tc_chain_notify(chain, skb, n->nlmsg_seq,
-- 
2.13.6


^ permalink raw reply related

* [PATCH net-next v4 08/17] net: sched: introduce reference counting for tcf_proto
From: Vlad Buslov @ 2019-02-11  8:55 UTC (permalink / raw)
  To: netdev; +Cc: jhs, xiyou.wangcong, jiri, davem, ast, daniel, Vlad Buslov
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

In order to remove dependency on rtnl lock and allow concurrent tcf_proto
modification, extend tcf_proto with reference counter. Implement helper
get/put functions for tcf proto and use them to modify cls API to always
take reference to tcf_proto while using it. Only release reference to
parent chain after releasing last reference to tp.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/sch_generic.h |  1 +
 net/sched/cls_api.c       | 53 ++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 85993d7efee6..4372c08fc4d9 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -322,6 +322,7 @@ struct tcf_proto {
 	void			*data;
 	const struct tcf_proto_ops	*ops;
 	struct tcf_chain	*chain;
+	refcount_t		refcnt;
 	struct rcu_head		rcu;
 };
 
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 3fce30ae9a9b..37c05b96898f 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -180,6 +180,7 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 	tp->protocol = protocol;
 	tp->prio = prio;
 	tp->chain = chain;
+	refcount_set(&tp->refcnt, 1);
 
 	err = tp->ops->init(tp);
 	if (err) {
@@ -193,14 +194,29 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 	return ERR_PTR(err);
 }
 
+static void tcf_proto_get(struct tcf_proto *tp)
+{
+	refcount_inc(&tp->refcnt);
+}
+
+static void tcf_chain_put(struct tcf_chain *chain);
+
 static void tcf_proto_destroy(struct tcf_proto *tp,
 			      struct netlink_ext_ack *extack)
 {
 	tp->ops->destroy(tp, extack);
+	tcf_chain_put(tp->chain);
 	module_put(tp->ops->owner);
 	kfree_rcu(tp, rcu);
 }
 
+static void tcf_proto_put(struct tcf_proto *tp,
+			  struct netlink_ext_ack *extack)
+{
+	if (refcount_dec_and_test(&tp->refcnt))
+		tcf_proto_destroy(tp, extack);
+}
+
 #define ASSERT_BLOCK_LOCKED(block)					\
 	lockdep_assert_held(&(block)->lock)
 
@@ -445,18 +461,18 @@ static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 
 static void tcf_chain_flush(struct tcf_chain *chain)
 {
-	struct tcf_proto *tp;
+	struct tcf_proto *tp, *tp_next;
 
 	mutex_lock(&chain->filter_chain_lock);
 	tp = tcf_chain_dereference(chain->filter_chain, chain);
+	RCU_INIT_POINTER(chain->filter_chain, NULL);
 	tcf_chain0_head_change(chain, NULL);
 	mutex_unlock(&chain->filter_chain_lock);
 
 	while (tp) {
-		RCU_INIT_POINTER(chain->filter_chain, tp->next);
-		tcf_proto_destroy(tp, NULL);
-		tp = rtnl_dereference(chain->filter_chain);
-		tcf_chain_put(chain);
+		tp_next = rcu_dereference_protected(tp->next, 1);
+		tcf_proto_put(tp, NULL);
+		tp = tp_next;
 	}
 }
 
@@ -1500,9 +1516,9 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain,
 {
 	if (*chain_info->pprev == chain->filter_chain)
 		tcf_chain0_head_change(chain, tp);
+	tcf_proto_get(tp);
 	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
 	rcu_assign_pointer(*chain_info->pprev, tp);
-	tcf_chain_hold(chain);
 }
 
 static void tcf_chain_tp_remove(struct tcf_chain *chain,
@@ -1514,7 +1530,6 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain,
 	if (tp == chain->filter_chain)
 		tcf_chain0_head_change(chain, next);
 	RCU_INIT_POINTER(*chain_info->pprev, next);
-	tcf_chain_put(chain);
 }
 
 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
@@ -1541,7 +1556,12 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 		}
 	}
 	chain_info->pprev = pprev;
-	chain_info->next = tp ? tp->next : NULL;
+	if (tp) {
+		chain_info->next = tp->next;
+		tcf_proto_get(tp);
+	} else {
+		chain_info->next = NULL;
+	}
 	return tp;
 }
 
@@ -1699,6 +1719,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	prio = TC_H_MAJ(t->tcm_info);
 	prio_allocate = false;
 	parent = t->tcm_parent;
+	tp = NULL;
 	cl = 0;
 
 	if (prio == 0) {
@@ -1816,6 +1837,12 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	if (chain)
 		tcf_chain_put(chain);
+	if (chain) {
+		if (tp && !IS_ERR(tp))
+			tcf_proto_put(tp, NULL);
+		if (!tp_created)
+			tcf_chain_put(chain);
+	}
 	tcf_block_release(q, block);
 	if (err == -EAGAIN)
 		/* Replay the request. */
@@ -1946,8 +1973,11 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	}
 
 errout:
-	if (chain)
+	if (chain) {
+		if (tp && !IS_ERR(tp))
+			tcf_proto_put(tp, NULL);
 		tcf_chain_put(chain);
+	}
 	tcf_block_release(q, block);
 	return err;
 
@@ -2038,8 +2068,11 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	}
 
 errout:
-	if (chain)
+	if (chain) {
+		if (tp && !IS_ERR(tp))
+			tcf_proto_put(tp, NULL);
 		tcf_chain_put(chain);
+	}
 	tcf_block_release(q, block);
 	return err;
 }
-- 
2.13.6


^ permalink raw reply related

* Re: [PATCH][next] can: at91_can: mark expected switch fall-throughs
From: Nicolas.Ferre @ 2019-02-11  9:03 UTC (permalink / raw)
  To: gustavo, wg, mkl, davem, alexandre.belloni, Ludovic.Desroches
  Cc: linux-can, netdev, linux-arm-kernel, linux-kernel
In-Reply-To: <20190208184444.GA28484@embeddedor>

On 08/02/2019 at 19:44, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> Notice that, in this particular case, the /* fall through */
> comments are placed at the bottom of the case statement, which
> is what GCC is expecting to find.
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> This patch is part of the ongoing efforts to enabling
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Looks good to me:
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

> ---
>   drivers/net/can/at91_can.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
> index d98c69045b17..1718c20f9c99 100644
> --- a/drivers/net/can/at91_can.c
> +++ b/drivers/net/can/at91_can.c
> @@ -902,7 +902,8 @@ static void at91_irq_err_state(struct net_device *dev,
>   				CAN_ERR_CRTL_TX_WARNING :
>   				CAN_ERR_CRTL_RX_WARNING;
>   		}
> -	case CAN_STATE_ERROR_WARNING:	/* fallthrough */
> +		/* fall through */
> +	case CAN_STATE_ERROR_WARNING:
>   		/*
>   		 * from: ERROR_ACTIVE, ERROR_WARNING
>   		 * to  : ERROR_PASSIVE, BUS_OFF
> @@ -951,7 +952,8 @@ static void at91_irq_err_state(struct net_device *dev,
>   		netdev_dbg(dev, "Error Active\n");
>   		cf->can_id |= CAN_ERR_PROT;
>   		cf->data[2] = CAN_ERR_PROT_ACTIVE;
> -	case CAN_STATE_ERROR_WARNING:	/* fallthrough */
> +		/* fall through */
> +	case CAN_STATE_ERROR_WARNING:
>   		reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_BOFF;
>   		reg_ier = AT91_IRQ_ERRP;
>   		break;
> 


-- 
Nicolas Ferre

^ permalink raw reply

* [PATCH net] sk_msg: Keep reference on socket file while psock lives
From: Jakub Sitnicki @ 2019-02-11  9:09 UTC (permalink / raw)
  To: netdev; +Cc: Daniel Borkmann, John Fastabend, Marek Majkowski

Backlog work for psock (sk_psock_backlog) might sleep while waiting for
memory to free up when sending packets. While sleeping, socket can
disappear from under our feet together with its wait queue because the
userspace has closed it.

This breaks an assumption in sk_stream_wait_memory, which expects the
wait queue to be still there when it wakes up resulting in a
use-after-free:

==================================================================
BUG: KASAN: use-after-free in remove_wait_queue+0x31/0x70
Write of size 8 at addr ffff888069a0c4e8 by task kworker/0:2/110

CPU: 0 PID: 110 Comm: kworker/0:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014
Workqueue: events sk_psock_backlog
Call Trace:
 print_address_description+0x6e/0x2b0
 ? remove_wait_queue+0x31/0x70
 kasan_report+0xfd/0x177
 ? remove_wait_queue+0x31/0x70
 ? remove_wait_queue+0x31/0x70
 remove_wait_queue+0x31/0x70
 sk_stream_wait_memory+0x4dd/0x5f0
 ? sk_stream_wait_close+0x1b0/0x1b0
 ? wait_woken+0xc0/0xc0
 ? tcp_current_mss+0xc5/0x110
 tcp_sendmsg_locked+0x634/0x15d0
 ? tcp_set_state+0x2e0/0x2e0
 ? __kasan_slab_free+0x1d1/0x230
 ? kmem_cache_free+0x70/0x140
 ? sk_psock_backlog+0x40c/0x4b0
 ? process_one_work+0x40b/0x660
 ? worker_thread+0x82/0x680
 ? kthread+0x1b9/0x1e0
 ? ret_from_fork+0x1f/0x30
 ? check_preempt_curr+0xaf/0x130
 ? iov_iter_kvec+0x5f/0x70
 ? kernel_sendmsg_locked+0xa0/0xe0
 skb_send_sock_locked+0x273/0x3c0
 ? skb_splice_bits+0x180/0x180
 ? start_thread+0xe0/0xe0
 ? update_min_vruntime.constprop.27+0x88/0xc0
 sk_psock_backlog+0xb3/0x4b0
 ? strscpy+0xbf/0x1e0
 process_one_work+0x40b/0x660
 worker_thread+0x82/0x680
 ? process_one_work+0x660/0x660
 kthread+0x1b9/0x1e0
 ? __kthread_create_on_node+0x250/0x250
 ret_from_fork+0x1f/0x30

Allocated by task 109:
 sock_alloc_inode+0x54/0x120
 alloc_inode+0x28/0xb0
 new_inode_pseudo+0x7/0x60
 sock_alloc+0x21/0xe0
 __sys_accept4+0xc2/0x330
 __x64_sys_accept+0x3b/0x50
 do_syscall_64+0xb2/0x3e0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 7:
 kfree+0x7f/0x140
 rcu_process_callbacks+0xe0/0x100
 __do_softirq+0xe5/0x29a

The buggy address belongs to the object at ffff888069a0c4e0
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 8 bytes inside of
 64-byte region [ffff888069a0c4e0, ffff888069a0c520)
The buggy address belongs to the page:
page:ffffea0001a68300 count:1 mapcount:0 mapping:ffff88806d4018c0 index:0x0
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000200 ffff88806d4018c0
raw: 0000000000000000 00000000002a002a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888069a0c380: fb fb fb fb fc fc fc fc fb fb fb fb fb fb fb fb
 ffff888069a0c400: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888069a0c480: 00 00 00 00 00 00 00 00 fc fc fc fc fb fb fb fb
                                                          ^
 ffff888069a0c500: fb fb fb fb fc fc fc fc fb fb fb fb fb fb fb fb
 ffff888069a0c580: fc fc fc fc fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Avoid it by keeping a reference to the socket file until the psock gets
destroyed.

While at it, rearrange the order of reference grabbing and
initialization to match the destructor in reverse.

Reported-by: Marek Majkowski <marek@cloudflare.com>
Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 net/core/skmsg.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 8c826603bf36..a38442b8580b 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -493,8 +493,13 @@ struct sk_psock *sk_psock_init(struct sock *sk, int node)
 	sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
 	refcount_set(&psock->refcnt, 1);
 
-	rcu_assign_sk_user_data(sk, psock);
+	/* Hold on to socket wait queue. Backlog work waits on it for
+	 * memory when sending. We must cancel work before socket wait
+	 * queue can go away.
+	 */
+	get_file(sk->sk_socket->file);
 	sock_hold(sk);
+	rcu_assign_sk_user_data(sk, psock);
 
 	return psock;
 }
@@ -558,6 +563,7 @@ static void sk_psock_destroy_deferred(struct work_struct *gc)
 	if (psock->sk_redir)
 		sock_put(psock->sk_redir);
 	sock_put(psock->sk);
+	fput(psock->sk->sk_socket->file);
 	kfree(psock);
 }
 
-- 
2.17.2


^ permalink raw reply related

* Re: How to set promiscuous mode
From: Phil Sutter @ 2019-02-11  9:14 UTC (permalink / raw)
  To: William Flanagan; +Cc: netdev
In-Reply-To: <f4c04e76-1e38-c742-5637-030cd74bc279@flanagan-consulting.com>

Hi,

On Sat, Feb 09, 2019 at 03:22:33PM -0500, William Flanagan wrote:
> Working with iproute2 for a task with Wireshark.  I don't see the 
> command in 'ip' to put an Ethernet port into promiscuous mode.  A reply 
> from the openSuse forum (below) tells me how.
> 
> I'm wondering if this should be in the 'MAN ip' page.

Please have a look at ip-link(8), its synopsis section at least lists
'promisc' option for 'ip link set' command. I'll follow-up with a patch
adding a little description, though.

Cheers, Phil

^ permalink raw reply

* [iproute PATCH] man: ip-link: Describe promisc mode
From: Phil Sutter @ 2019-02-11  9:17 UTC (permalink / raw)
  To: Stephen Hemminger; +Cc: netdev, William Flanagan
In-Reply-To: <20190211091418.GL26388@orbyte.nwl.cc>

Briefly explain what it is and where it's typically used.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 man/man8/ip-link.8.in | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 73d37c190fffa..5c327f01b6b45 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -1780,6 +1780,14 @@ flag on the device. Indicates that address can change when interface goes down (
 .B NOT
 used by the Linux).
 
+.TP
+.BR "promisc on " or " promisc off"
+change the
+.B PROMISC
+flag on the device. This requests receipt of all packets arriving at the NIC
+irrespective of their destination MAC address. It is typically used by traffic
+sniffers and also set by Linux bridges for their ports.
+
 .TP
 .BI name " NAME"
 change the name of the device. This operation is not
-- 
2.20.1


^ permalink raw reply related

* [PATCH v2 net-next] Revert wake_on_lan devlink parameter
From: Vasundhara Volam @ 2019-02-11  9:16 UTC (permalink / raw)
  To: davem; +Cc: netdev

As per discussion with Jakub Kicinski and Michal Kubecek,
this will be better addressed by soon-too-come ethtool netlink
API with additional indication that given WoL configuration request
is supposed to be persisted.

Retain bnxt_en code for devlink port param table registration.
There will be follow up patches to add some devlink port params
for bnxt_en driver.

v1->v2:
Combine 2 patches into 1 patch to avoid build failures.

Vasundhara Volam (1):
  Revert "devlink: Add a generic wake_on_lan port parameter"

 drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c | 19 +------------------
 drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h |  1 -
 include/net/devlink.h                             |  8 --------
 net/core/devlink.c                                |  5 -----
 4 files changed, 1 insertion(+), 32 deletions(-)

-- 
1.8.3.1


^ permalink raw reply

* [PATCH v2 net-next] Revert "devlink: Add a generic wake_on_lan port parameter"
From: Vasundhara Volam @ 2019-02-11  9:16 UTC (permalink / raw)
  To: davem; +Cc: netdev
In-Reply-To: <1549876577-195336-1-git-send-email-vasundhara-v.volam@broadcom.com>

This reverts commit b639583f9e36d044ac1b13090ae812266992cbac.

As per discussion with Jakub Kicinski and Michal Kubecek,
this will be better addressed by soon-too-come ethtool netlink
API with additional indication that given configuration request
is supposed to be persisted.

Also, remove the parameter support from bnxt_en driver.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Cc: Michal Kubecek <mkubecek@suse.cz>
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c | 19 +------------------
 drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h |  1 -
 include/net/devlink.h                             |  8 --------
 net/core/devlink.c                                |  5 -----
 4 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c
index 2955e40..e1feb97 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c
@@ -37,8 +37,6 @@ enum bnxt_dl_param_id {
 	 NVM_OFF_MSIX_VEC_PER_PF_MIN, BNXT_NVM_SHARED_CFG, 7},
 	{BNXT_DEVLINK_PARAM_ID_GRE_VER_CHECK, NVM_OFF_DIS_GRE_VER_CHECK,
 	 BNXT_NVM_SHARED_CFG, 1},
-
-	{DEVLINK_PARAM_GENERIC_ID_WOL, NVM_OFF_WOL, BNXT_NVM_PORT_CFG, 1},
 };
 
 static int bnxt_hwrm_nvm_req(struct bnxt *bp, u32 param_id, void *msg,
@@ -72,8 +70,7 @@ static int bnxt_hwrm_nvm_req(struct bnxt *bp, u32 param_id, void *msg,
 	bytesize = roundup(nvm_param.num_bits, BITS_PER_BYTE) / BITS_PER_BYTE;
 	switch (bytesize) {
 	case 1:
-		if (nvm_param.num_bits == 1 &&
-		    nvm_param.id != DEVLINK_PARAM_GENERIC_ID_WOL)
+		if (nvm_param.num_bits == 1)
 			buf = &val->vbool;
 		else
 			buf = &val->vu8;
@@ -167,17 +164,6 @@ static int bnxt_dl_msix_validate(struct devlink *dl, u32 id,
 	return 0;
 }
 
-static int bnxt_dl_wol_validate(struct devlink *dl, u32 id,
-				union devlink_param_value val,
-				struct netlink_ext_ack *extack)
-{
-	if (val.vu8 && val.vu8 != DEVLINK_PARAM_WAKE_MAGIC) {
-		NL_SET_ERR_MSG_MOD(extack, "WOL type is not supported");
-		return -EINVAL;
-	}
-	return 0;
-}
-
 static const struct devlink_param bnxt_dl_params[] = {
 	DEVLINK_PARAM_GENERIC(ENABLE_SRIOV,
 			      BIT(DEVLINK_PARAM_CMODE_PERMANENT),
@@ -203,9 +189,6 @@ static int bnxt_dl_wol_validate(struct devlink *dl, u32 id,
 };
 
 static const struct devlink_param bnxt_dl_port_params[] = {
-	DEVLINK_PARAM_GENERIC(WOL, BIT(DEVLINK_PARAM_CMODE_PERMANENT),
-			      bnxt_dl_nvm_param_get, bnxt_dl_nvm_param_set,
-			      bnxt_dl_wol_validate),
 };
 
 int bnxt_dl_register(struct bnxt *bp)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h
index da065ca..5b6b2c7 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.h
@@ -35,7 +35,6 @@ static inline void bnxt_link_bp_to_dl(struct bnxt *bp, struct devlink *dl)
 
 #define NVM_OFF_MSIX_VEC_PER_PF_MAX	108
 #define NVM_OFF_MSIX_VEC_PER_PF_MIN	114
-#define NVM_OFF_WOL			152
 #define NVM_OFF_IGNORE_ARI		164
 #define NVM_OFF_DIS_GRE_VER_CHECK	171
 #define NVM_OFF_ENABLE_SRIOV		401
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 2b384a3..083a8b3 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -370,17 +370,12 @@ enum devlink_param_generic_id {
 	DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MAX,
 	DEVLINK_PARAM_GENERIC_ID_MSIX_VEC_PER_PF_MIN,
 	DEVLINK_PARAM_GENERIC_ID_FW_LOAD_POLICY,
-	DEVLINK_PARAM_GENERIC_ID_WOL,
 
 	/* add new param generic ids above here*/
 	__DEVLINK_PARAM_GENERIC_ID_MAX,
 	DEVLINK_PARAM_GENERIC_ID_MAX = __DEVLINK_PARAM_GENERIC_ID_MAX - 1,
 };
 
-enum devlink_param_wol_types {
-	DEVLINK_PARAM_WAKE_MAGIC = (1 << 0),
-};
-
 #define DEVLINK_PARAM_GENERIC_INT_ERR_RESET_NAME "internal_error_reset"
 #define DEVLINK_PARAM_GENERIC_INT_ERR_RESET_TYPE DEVLINK_PARAM_TYPE_BOOL
 
@@ -405,9 +400,6 @@ enum devlink_param_wol_types {
 #define DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_NAME "fw_load_policy"
 #define DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_TYPE DEVLINK_PARAM_TYPE_U8
 
-#define DEVLINK_PARAM_GENERIC_WOL_NAME "wake_on_lan"
-#define DEVLINK_PARAM_GENERIC_WOL_TYPE DEVLINK_PARAM_TYPE_U8
-
 #define DEVLINK_PARAM_GENERIC(_id, _cmodes, _get, _set, _validate)	\
 {									\
 	.id = DEVLINK_PARAM_GENERIC_ID_##_id,				\
diff --git a/net/core/devlink.c b/net/core/devlink.c
index e6a015b..00269a9 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2701,11 +2701,6 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 		.name = DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_NAME,
 		.type = DEVLINK_PARAM_GENERIC_FW_LOAD_POLICY_TYPE,
 	},
-	{
-		.id = DEVLINK_PARAM_GENERIC_ID_WOL,
-		.name = DEVLINK_PARAM_GENERIC_WOL_NAME,
-		.type = DEVLINK_PARAM_GENERIC_WOL_TYPE,
-	},
 };
 
 static int devlink_param_generic_verify(const struct devlink_param *param)
-- 
1.8.3.1


^ permalink raw reply related

* Re: [Resend PATCH] mt76: change the return type of mt76_dma_attach()
From: Kalle Valo @ 2019-02-11  9:19 UTC (permalink / raw)
  To: Ryder Lee
  Cc: Lorenzo Bianconi, Felix Fietkau, Roy Luo, linux-wireless,
	linux-kernel, netdev, linux-mediatek
In-Reply-To: <228fdddb9ca96e8ce861e324eb9039722cf18f49.1549850911.git.ryder.lee@mediatek.com>

Ryder Lee <ryder.lee@mediatek.com> writes:

> There is no need to return 0 in mt76_dma_attach(), so switch it to void.
>
> Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>

When you send a new version mark it as v2:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#patch_version_missing

And add a changelog:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#changelog_missing

No need to resend because of this, but please do remember this in the
future.

-- 
Kalle Valo

^ permalink raw reply

* Re: [PATCH net-next v3] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs
From: Nicolas Dichtel @ 2019-02-11  9:38 UTC (permalink / raw)
  To: Callum Sinclair, davem, kuznet, yoshfuji, nikolay, netdev,
	linux-kernel
In-Reply-To: <20190211035412.29218-2-callum.sinclair@alliedtelesis.co.nz>

Le 11/02/2019 à 04:54, Callum Sinclair a écrit :
> v1 -> v2:
> Implemented additional flags for static entries
> v2 -> v3:
> Cleaned up flag logic so any combination of routes can be cleared.
> Fixed style errors
> Fixed incorrect flag values
nit: those lines are usually put after the '---', thus they don't appear in the
final commit log (they are useful for reviewers only).

> 
> Currently the only way to clear the forwarding cache was to delete the
> entries one by one using the MRT_DEL_MFC socket option or to destroy and
> recreate the socket.
> 
> Create a new socket option which with the use of optional flags can
> clear any combination of multicast entries (static or not static) and
> multicast vifs (static or not static).
> 
> Calling the new socket option MRT_FLUSH with the flags MRT_FLUSH_MFC and
> MRT_FLUSH_VIFS will clear all entries and vifs on the socket except for
> static entries.
> 
> Signed-off-by: Callum Sinclair <callum.sinclair@alliedtelesis.co.nz>
> ---
ie, here

>  include/uapi/linux/mroute.h  |  9 ++++-
>  include/uapi/linux/mroute6.h |  9 ++++-
>  net/ipv4/ipmr.c              | 73 ++++++++++++++++++++-------------
>  net/ipv6/ip6mr.c             | 78 +++++++++++++++++++++++-------------
>  4 files changed, 112 insertions(+), 57 deletions(-)
> 
> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index 5d37a9ccce63..11c8c1fc1124 100644
> --- a/include/uapi/linux/mroute.h
> +++ b/include/uapi/linux/mroute.h
> @@ -28,12 +28,19 @@
>  #define MRT_TABLE	(MRT_BASE+9)	/* Specify mroute table ID		*/
>  #define MRT_ADD_MFC_PROXY	(MRT_BASE+10)	/* Add a (*,*|G) mfc entry	*/
>  #define MRT_DEL_MFC_PROXY	(MRT_BASE+11)	/* Del a (*,*|G) mfc entry	*/
> -#define MRT_MAX		(MRT_BASE+11)
> +#define MRT_FLUSH	(MRT_BASE+12)	/* Flush all mfc entries and/or vifs	*/
> +#define MRT_MAX		(MRT_BASE+12)
>  
>  #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* MRT_FLUSH optional flags */
> +#define MRT_FLUSH_MFC	1	/* Flush multicast entries */
> +#define MRT_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
> +#define MRT_FLUSH_VIFS	4	/* Flush multicast vifs */
> +#define MRT_FLUSH_VIFS_STATIC	8	/* Flush static multicast vifs */
> +
>  #define MAXVIFS		32
>  typedef unsigned long vifbitmap_t;	/* User mode code depends on this lot */
>  typedef unsigned short vifi_t;
> diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
> index 9999cc006390..ac84ef11b29c 100644
> --- a/include/uapi/linux/mroute6.h
> +++ b/include/uapi/linux/mroute6.h
> @@ -31,12 +31,19 @@
>  #define MRT6_TABLE	(MRT6_BASE+9)	/* Specify mroute table ID		*/
>  #define MRT6_ADD_MFC_PROXY	(MRT6_BASE+10)	/* Add a (*,*|G) mfc entry	*/
>  #define MRT6_DEL_MFC_PROXY	(MRT6_BASE+11)	/* Del a (*,*|G) mfc entry	*/
> -#define MRT6_MAX	(MRT6_BASE+11)
> +#define MRT6_FLUSH	(MRT6_BASE+12)	/* Flush all mfc entries and/or vifs	*/
> +#define MRT6_MAX	(MRT6_BASE+12)
>  
>  #define SIOCGETMIFCNT_IN6	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT_IN6	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* MRT6_FLUSH optional flags */
> +#define MRT6_FLUSH_MFC	1	/* Flush multicast entries */
> +#define MRT6_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
> +#define MRT6_FLUSH_VIFS	4	/* Flushing multicast vifs */
> +#define MRT6_FLUSH_VIFS_STATIC	8	/* Flush static multicast vifs */
> +
>  #define MAXMIFS		32
>  typedef unsigned long mifbitmap_t;	/* User mode code depends on this lot */
>  typedef unsigned short mifi_t;
> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
> index e536970557dd..2c95ef8cf224 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -110,7 +110,7 @@ static int ipmr_cache_report(struct mr_table *mrt,
>  static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
>  				 int cmd);
>  static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
> -static void mroute_clean_tables(struct mr_table *mrt, bool all);
> +static void mroute_clean_tables(struct mr_table *mrt, int flags);
>  static void ipmr_expire_process(struct timer_list *t);
>  
>  #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
> @@ -415,7 +415,8 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
>  static void ipmr_free_table(struct mr_table *mrt)
>  {
>  	del_timer_sync(&mrt->ipmr_expire_timer);
> -	mroute_clean_tables(mrt, true);
> +	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
> +						MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
nit: MRT_FLUSH_MFC must be aligned with 'mrt'

>  	rhltable_destroy(&mrt->mfc_hash);
>  	kfree(mrt);
>  }
> @@ -1296,7 +1297,7 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
>  }
>  
>  /* Close the multicast socket, and clear the vif tables etc */
> -static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +static void mroute_clean_tables(struct mr_table *mrt, int flags)
>  {
>  	struct net *net = read_pnet(&mrt->net);
>  	struct mr_mfc *c, *tmp;
> @@ -1305,35 +1306,42 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
>  	int i;
>  
>  	/* Shut down all active vif entries */
> -	for (i = 0; i < mrt->maxvif; i++) {
> -		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
> -			continue;
> -		vif_delete(mrt, i, 0, &list);
> +	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
> +		for (i = 0; i < mrt->maxvif; i++) {
> +			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
> +			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
> +			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH)))
s/MRT_FLUSH/MRT_FLUSH_VIFS


Regards,
Nicolas

^ permalink raw reply

* Re: [Xen-devel] [PATCH net-next] xen-netback: mark expected switch fall-through
From: Jan Beulich @ 2019-02-11  9:50 UTC (permalink / raw)
  To: Gustavo A.R.Silva
  Cc: Paul Durrant, Wei Liu, davem, xen-devel, linux-kernel, netdev
In-Reply-To: <20190208195838.GA11878@embeddedor>

>>> On 08.02.19 at 20:58, <gustavo@embeddedor.com> wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> This patch is part of the ongoing efforts to enabling
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/net/xen-netback/xenbus.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/xen-netback/xenbus.c 
> b/drivers/net/xen-netback/xenbus.c
> index 2625740bdc4a..330ddb64930f 100644
> --- a/drivers/net/xen-netback/xenbus.c
> +++ b/drivers/net/xen-netback/xenbus.c
> @@ -655,7 +655,7 @@ static void frontend_changed(struct xenbus_device *dev,
>  		set_backend_state(be, XenbusStateClosed);
>  		if (xenbus_dev_is_online(dev))
>  			break;
> -		/* fall through if not online */
> +		/* fall through - if not online */
>  	case XenbusStateUnknown:

Considering the fall-through was already annotated, I don't think
title and description really justify the change. Is the compiler after
a particular wording here?

Jan



^ permalink raw reply

* [PATCH net-next 1/2] net: marvell: mvpp2: add mvpp2_is_xlg() helper
From: Russell King @ 2019-02-11 10:23 UTC (permalink / raw)
  To: Antoine Tenart, Maxime Chevallier
  Cc: Baruch Siach, Sven Auhagen, David S. Miller, netdev

Add a mvpp2_is_xlg() helper to identify whether the interface mode
should be using the XLGMAC rather than the GMAC.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index fdd538c28f8a..03c79618bfef 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -965,6 +965,11 @@ mvpp2_shared_interrupt_mask_unmask(struct mvpp2_port *port, bool mask)
 }
 
 /* Port configuration routines */
+static bool mvpp2_is_xlg(phy_interface_t interface)
+{
+	return interface == PHY_INTERFACE_MODE_10GKR ||
+	       interface == PHY_INTERFACE_MODE_XAUI;
+}
 
 static void mvpp22_gop_init_rgmii(struct mvpp2_port *port)
 {
@@ -1196,9 +1201,7 @@ static void mvpp2_port_enable(struct mvpp2_port *port)
 	u32 val;
 
 	/* Only GOP port 0 has an XLG MAC */
-	if (port->gop_id == 0 &&
-	    (port->phy_interface == PHY_INTERFACE_MODE_XAUI ||
-	     port->phy_interface == PHY_INTERFACE_MODE_10GKR)) {
+	if (port->gop_id == 0 && mvpp2_is_xlg(port->phy_interface)) {
 		val = readl(port->base + MVPP22_XLG_CTRL0_REG);
 		val |= MVPP22_XLG_CTRL0_PORT_EN |
 		       MVPP22_XLG_CTRL0_MAC_RESET_DIS;
@@ -1217,9 +1220,7 @@ static void mvpp2_port_disable(struct mvpp2_port *port)
 	u32 val;
 
 	/* Only GOP port 0 has an XLG MAC */
-	if (port->gop_id == 0 &&
-	    (port->phy_interface == PHY_INTERFACE_MODE_XAUI ||
-	     port->phy_interface == PHY_INTERFACE_MODE_10GKR)) {
+	if (port->gop_id == 0 && mvpp2_is_xlg(port->phy_interface)) {
 		val = readl(port->base + MVPP22_XLG_CTRL0_REG);
 		val &= ~MVPP22_XLG_CTRL0_PORT_EN;
 		writel(val, port->base + MVPP22_XLG_CTRL0_REG);
@@ -3161,8 +3162,7 @@ static void mvpp22_mode_reconfigure(struct mvpp2_port *port)
 		ctrl3 = readl(port->base + MVPP22_XLG_CTRL3_REG);
 		ctrl3 &= ~MVPP22_XLG_CTRL3_MACMODESELECT_MASK;
 
-		if (port->phy_interface == PHY_INTERFACE_MODE_XAUI ||
-		    port->phy_interface == PHY_INTERFACE_MODE_10GKR)
+		if (mvpp2_is_xlg(port->phy_interface))
 			ctrl3 |= MVPP22_XLG_CTRL3_MACMODESELECT_10G;
 		else
 			ctrl3 |= MVPP22_XLG_CTRL3_MACMODESELECT_GMAC;
@@ -3170,9 +3170,7 @@ static void mvpp22_mode_reconfigure(struct mvpp2_port *port)
 		writel(ctrl3, port->base + MVPP22_XLG_CTRL3_REG);
 	}
 
-	if (port->gop_id == 0 &&
-	    (port->phy_interface == PHY_INTERFACE_MODE_XAUI ||
-	     port->phy_interface == PHY_INTERFACE_MODE_10GKR))
+	if (port->gop_id == 0 && mvpp2_is_xlg(port->phy_interface))
 		mvpp2_xlg_max_rx_size_set(port);
 	else
 		mvpp2_gmac_max_rx_size_set(port);
-- 
2.7.4


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