1 files changed, 21 insertions, 89 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index c43c96554a3e..889e7e3d3e8a 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -207,6 +207,7 @@ static const struct nla_policy devlink_selftest_nl_policy[DEVLINK_ATTR_SELFTEST_
 
 static DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
 #define DEVLINK_REGISTERED XA_MARK_1
+#define DEVLINK_UNREGISTERING XA_MARK_2
 
 /* devlink instances are open to the access from the user space after
  * devlink_register() call. Such logical barrier allows us to have certain
@@ -224,12 +225,6 @@ static DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
 #define ASSERT_DEVLINK_NOT_REGISTERED(d)                                       \
 	WARN_ON_ONCE(xa_get_mark(&devlinks, (d)->index, DEVLINK_REGISTERED))
 
-/* devlink_mutex
- *
- * An overall lock guarding every operation coming from userspace.
- */
-static DEFINE_MUTEX(devlink_mutex);
-
 struct net *devlink_net(const struct devlink *devlink)
 {
 	return read_pnet(&devlink->_net);
@@ -305,6 +300,14 @@ retry:
 	devlink = xa_find_fn(&devlinks, indexp, ULONG_MAX, DEVLINK_REGISTERED);
 	if (!devlink)
 		goto unlock;
+
+	/* In case devlink_unregister() was already called and "unregistering"
+	 * mark was set, do not allow to get a devlink reference here.
+	 * This prevents live-lock of devlink_unregister() wait for completion.
+	 */
+	if (xa_get_mark(&devlinks, *indexp, DEVLINK_UNREGISTERING))
+		goto retry;
+
 	/* For a possible retry, the xa_find_after() should be always used */
 	xa_find_fn = xa_find_after;
 	if (!devlink_try_get(devlink))
@@ -759,12 +762,6 @@ devlink_region_snapshot_get_by_id(struct devlink_region *region, u32 id)
 #define DEVLINK_NL_FLAG_NEED_RATE_NODE		BIT(3)
 #define DEVLINK_NL_FLAG_NEED_LINECARD		BIT(4)
 
-/* The per devlink instance lock is taken by default in the pre-doit
- * operation, yet several commands do not require this. The global
- * devlink lock is taken and protects from disruption by user-calls.
- */
-#define DEVLINK_NL_FLAG_NO_LOCK			BIT(5)
-
 static int devlink_nl_pre_doit(const struct genl_ops *ops,
 			       struct sk_buff *skb, struct genl_info *info)
 {
@@ -773,14 +770,10 @@ static int devlink_nl_pre_doit(const struct genl_ops *ops,
 	struct devlink *devlink;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlink = devlink_get_from_attrs(genl_info_net(info), info->attrs);
-	if (IS_ERR(devlink)) {
-		mutex_unlock(&devlink_mutex);
+	if (IS_ERR(devlink))
 		return PTR_ERR(devlink);
-	}
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
-		devl_lock(devlink);
+	devl_lock(devlink);
 	info->user_ptr[0] = devlink;
 	if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_PORT) {
 		devlink_port = devlink_port_get_from_info(devlink, info);
@@ -822,10 +815,8 @@ static int devlink_nl_pre_doit(const struct genl_ops *ops,
 	return 0;
 
 unlock:
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
-		devl_unlock(devlink);
+	devl_unlock(devlink);
 	devlink_put(devlink);
-	mutex_unlock(&devlink_mutex);
 	return err;
 }
 
@@ -840,10 +831,8 @@ static void devlink_nl_post_doit(const struct genl_ops *ops,
 		linecard = info->user_ptr[1];
 		devlink_linecard_put(linecard);
 	}
-	if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
-		devl_unlock(devlink);
+	devl_unlock(devlink);
 	devlink_put(devlink);
-	mutex_unlock(&devlink_mutex);
 }
 
 static struct genl_family devlink_nl_family;
@@ -1408,7 +1397,6 @@ static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(devlink_rate, &devlink->rate_list, list) {
@@ -1433,7 +1421,6 @@ static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -1504,7 +1491,6 @@ static int devlink_nl_cmd_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (idx < start) {
 			idx++;
@@ -1521,8 +1507,6 @@ static int devlink_nl_cmd_get_dumpit(struct sk_buff *msg,
 		idx++;
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -1559,7 +1543,6 @@ static int devlink_nl_cmd_port_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(devlink_port, &devlink->port_list, list) {
@@ -1583,8 +1566,6 @@ static int devlink_nl_cmd_port_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -2238,7 +2219,6 @@ static int devlink_nl_cmd_linecard_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		mutex_lock(&devlink->linecards_lock);
 		list_for_each_entry(linecard, &devlink->linecard_list, list) {
@@ -2265,8 +2245,6 @@ static int devlink_nl_cmd_linecard_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -2503,7 +2481,6 @@ static int devlink_nl_cmd_sb_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(devlink_sb, &devlink->sb_list, list) {
@@ -2527,8 +2504,6 @@ static int devlink_nl_cmd_sb_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -2648,7 +2623,6 @@ static int devlink_nl_cmd_sb_pool_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (!devlink->ops->sb_pool_get)
 			goto retry;
@@ -2672,8 +2646,6 @@ retry:
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -2865,7 +2837,6 @@ static int devlink_nl_cmd_sb_port_pool_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (!devlink->ops->sb_port_pool_get)
 			goto retry;
@@ -2889,8 +2860,6 @@ retry:
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -3110,7 +3079,6 @@ devlink_nl_cmd_sb_tc_pool_bind_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (!devlink->ops->sb_tc_pool_bind_get)
 			goto retry;
@@ -3135,8 +3103,6 @@ retry:
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -4908,7 +4874,6 @@ static int devlink_nl_cmd_selftests_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (idx < start || !devlink->ops->selftest_check)
 			goto inc;
@@ -4927,7 +4892,6 @@ inc:
 		idx++;
 		devlink_put(devlink);
 	}
-	mutex_unlock(&devlink_mutex);
 
 	if (err != -EMSGSIZE)
 		return err;
@@ -5393,7 +5357,6 @@ static int devlink_nl_cmd_param_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(param_item, &devlink->param_list, list) {
@@ -5419,8 +5382,6 @@ static int devlink_nl_cmd_param_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -5621,7 +5582,6 @@ static int devlink_nl_cmd_port_param_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(devlink_port, &devlink->port_list, list) {
@@ -5652,8 +5612,6 @@ static int devlink_nl_cmd_port_param_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	if (err != -EMSGSIZE)
 		return err;
 
@@ -6208,7 +6166,6 @@ static int devlink_nl_cmd_region_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		err = devlink_nl_cmd_region_get_devlink_dumpit(msg, cb, devlink,
 							       &idx, start);
@@ -6217,7 +6174,6 @@ static int devlink_nl_cmd_region_get_dumpit(struct sk_buff *msg,
 			goto out;
 	}
 out:
-	mutex_unlock(&devlink_mutex);
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -6483,12 +6439,9 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 
 	start_offset = *((u64 *)&cb->args[0]);
 
-	mutex_lock(&devlink_mutex);
 	devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs);
-	if (IS_ERR(devlink)) {
-		err = PTR_ERR(devlink);
-		goto out_dev;
-	}
+	if (IS_ERR(devlink))
+		return PTR_ERR(devlink);
 
 	devl_lock(devlink);
 
@@ -6588,8 +6541,6 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 	genlmsg_end(skb, hdr);
 	devl_unlock(devlink);
 	devlink_put(devlink);
-	mutex_unlock(&devlink_mutex);
-
 	return skb->len;
 
 nla_put_failure:
@@ -6597,8 +6548,6 @@ nla_put_failure:
 out_unlock:
 	devl_unlock(devlink);
 	devlink_put(devlink);
-out_dev:
-	mutex_unlock(&devlink_mutex);
 	return err;
 }
 
@@ -6747,7 +6696,6 @@ static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err = 0;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		if (idx < start || !devlink->ops->info_get)
 			goto inc;
@@ -6768,7 +6716,6 @@ inc:
 		idx++;
 		devlink_put(devlink);
 	}
-	mutex_unlock(&devlink_mutex);
 
 	if (err != -EMSGSIZE)
 		return err;
@@ -7847,18 +7794,13 @@ devlink_health_reporter_get_from_cb(struct netlink_callback *cb)
 	struct nlattr **attrs = info->attrs;
 	struct devlink *devlink;
 
-	mutex_lock(&devlink_mutex);
 	devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs);
 	if (IS_ERR(devlink))
-		goto unlock;
+		return NULL;
 
 	reporter = devlink_health_reporter_get_from_attrs(devlink, attrs);
 	devlink_put(devlink);
-	mutex_unlock(&devlink_mutex);
 	return reporter;
-unlock:
-	mutex_unlock(&devlink_mutex);
-	return NULL;
 }
 
 void
@@ -7924,7 +7866,6 @@ devlink_nl_cmd_health_reporter_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		mutex_lock(&devlink->reporters_lock);
 		list_for_each_entry(reporter, &devlink->reporter_list,
@@ -7976,8 +7917,6 @@ devlink_nl_cmd_health_reporter_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -8510,7 +8449,6 @@ static int devlink_nl_cmd_trap_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(trap_item, &devlink->trap_list, list) {
@@ -8534,8 +8472,6 @@ static int devlink_nl_cmd_trap_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -8730,7 +8666,6 @@ static int devlink_nl_cmd_trap_group_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(group_item, &devlink->trap_group_list,
@@ -8755,8 +8690,6 @@ static int devlink_nl_cmd_trap_group_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -9037,7 +8970,6 @@ static int devlink_nl_cmd_trap_policer_get_dumpit(struct sk_buff *msg,
 	int idx = 0;
 	int err;
 
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
 		devl_lock(devlink);
 		list_for_each_entry(policer_item, &devlink->trap_policer_list,
@@ -9062,8 +8994,6 @@ static int devlink_nl_cmd_trap_policer_get_dumpit(struct sk_buff *msg,
 		devlink_put(devlink);
 	}
 out:
-	mutex_unlock(&devlink_mutex);
-
 	cb->args[0] = idx;
 	return msg->len;
 }
@@ -9405,7 +9335,6 @@ static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_reload,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PARAM_GET,
@@ -9576,6 +9505,7 @@ static struct genl_family devlink_nl_family __ro_after_init = {
 	.maxattr	= DEVLINK_ATTR_MAX,
 	.policy = devlink_nl_policy,
 	.netnsok	= true,
+	.parallel_ops	= true,
 	.pre_doit	= devlink_nl_pre_doit,
 	.post_doit	= devlink_nl_post_doit,
 	.module		= THIS_MODULE,
@@ -9809,11 +9739,13 @@ void devlink_unregister(struct devlink *devlink)
 	ASSERT_DEVLINK_REGISTERED(devlink);
 	/* Make sure that we are in .remove() routine */
 
+	xa_set_mark(&devlinks, devlink->index, DEVLINK_UNREGISTERING);
 	devlink_put(devlink);
 	wait_for_completion(&devlink->comp);
 
 	devlink_notify_unregister(devlink);
 	xa_clear_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
+	xa_clear_mark(&devlinks, devlink->index, DEVLINK_UNREGISTERING);
 }
 EXPORT_SYMBOL_GPL(devlink_unregister);
 
@@ -12493,18 +12425,18 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
 	/* In case network namespace is getting destroyed, reload
 	 * all devlink instances from this namespace into init_net.
 	 */
-	mutex_lock(&devlink_mutex);
 	devlinks_xa_for_each_registered_get(net, index, devlink) {
 		WARN_ON(!(devlink->features & DEVLINK_F_RELOAD));
+		mutex_lock(&devlink->lock);
 		err = devlink_reload(devlink, &init_net,
 				     DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
 				     DEVLINK_RELOAD_LIMIT_UNSPEC,
 				     &actions_performed, NULL);
+		mutex_unlock(&devlink->lock);
 		if (err && err != -EOPNOTSUPP)
 			pr_warn("Failed to reload devlink instance into init_net\n");
 		devlink_put(devlink);
 	}
-	mutex_unlock(&devlink_mutex);
 }
 
 static struct pernet_operations devlink_pernet_ops __net_initdata = {