diff mbox

[net-next,37/40] rtnetlink: Compute and store minimum ifinfo dump size

Message ID 1307449995-9458-38-git-send-email-jeffrey.t.kirsher@intel.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Kirsher, Jeffrey T June 7, 2011, 12:33 p.m. UTC 
From: Greg Rose <gregory.v.rose@intel.com>

The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Evan Swanson <evan.swanson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 include/linux/netlink.h              |    6 ++-
 include/net/rtnetlink.h              |    7 +++-
 net/bridge/br_netlink.c              |   15 ++++++---
 net/core/fib_rules.c                 |    6 ++--
 net/core/neighbour.c                 |   11 +++---
 net/core/rtnetlink.c                 |   60 +++++++++++++++++++++++++++------
 net/dcb/dcbnl.c                      |    4 +-
 net/decnet/dn_dev.c                  |    6 ++--
 net/decnet/dn_fib.c                  |    4 +-
 net/decnet/dn_route.c                |    5 ++-
 net/ipv4/devinet.c                   |    6 ++--
 net/ipv4/fib_frontend.c              |    6 ++--
 net/ipv4/inet_diag.c                 |    2 +-
 net/ipv4/ipmr.c                      |    3 +-
 net/ipv4/route.c                     |    2 +-
 net/ipv6/addrconf.c                  |   16 ++++++---
 net/ipv6/addrlabel.c                 |    9 +++--
 net/ipv6/ip6_fib.c                   |    3 +-
 net/ipv6/ip6mr.c                     |    3 +-
 net/ipv6/route.c                     |    6 ++--
 net/netfilter/ipset/ip_set_core.c    |    2 +-
 net/netfilter/nf_conntrack_netlink.c |    4 +-
 net/netlink/af_netlink.c             |   17 ++++++---
 net/netlink/genetlink.c              |    2 +-
 net/phonet/pn_netlink.c              |   13 ++++---
 net/sched/act_api.c                  |    7 ++--
 net/sched/cls_api.c                  |    6 ++--
 net/sched/sch_api.c                  |   12 +++---
 net/xfrm/xfrm_user.c                 |    3 +-
 29 files changed, 157 insertions(+), 89 deletions(-)

Comments

Johannes Berg June 8, 2011, 6:09 a.m. UTC | #1 
On Tue, 2011-06-07 at 05:33 -0700, Jeff Kirsher wrote:
> From: Greg Rose <gregory.v.rose@intel.com>
> 
> The message size allocated for rtnl ifinfo dumps was limited to
> a single page.  This is not enough for additional interface info
> available with devices that support SR-IOV and caused a bug in
> which VF info would not be displayed if more than approximately
> 40 VFs were created per interface.
> 
> Implement a new function pointer for the rtnl_register service that will
> calculate the amount of data required for the ifinfo dump and allocate
> enough data to satisfy the request.

Curious. Weren't dumps supposed to be split up into small chunks and
then delivered? Where is this splitting going wrong, and could it be
improved to split into smaller pieces?

johannes

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David Miller June 8, 2011, 7:12 a.m. UTC | #2 
From: Johannes Berg <johannes@sipsolutions.net>
Date: Wed, 08 Jun 2011 08:09:57 +0200

> Curious. Weren't dumps supposed to be split up into small chunks and
> then delivered? Where is this splitting going wrong, and could it be
> improved to split into smaller pieces?

You can only split at the individual object boundary.

And in these cases individual single network device instances are too
large to go in one SKB.
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diff mbox

Patch

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index a9dd895..fdd0188 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -221,7 +221,8 @@  struct netlink_callback {
 	int			(*dump)(struct sk_buff * skb,
 					struct netlink_callback *cb);
 	int			(*done)(struct netlink_callback *cb);
-	int			family;
+	u16			family;
+	u16			min_dump_alloc;
 	long			args[6];
 };
 
@@ -259,7 +260,8 @@  __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
 extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 			      const struct nlmsghdr *nlh,
 			      int (*dump)(struct sk_buff *skb, struct netlink_callback*),
-			      int (*done)(struct netlink_callback*));
+			      int (*done)(struct netlink_callback*),
+			      u16 min_dump_alloc);
 
 
 #define NL_NONROOT_RECV 0x1
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 4093ca7..678f1ff 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -6,11 +6,14 @@ 
 
 typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *, void *);
 typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
+typedef u16 (*rtnl_calcit_func)(struct sk_buff *);
 
 extern int	__rtnl_register(int protocol, int msgtype,
-				rtnl_doit_func, rtnl_dumpit_func);
+				rtnl_doit_func, rtnl_dumpit_func,
+				rtnl_calcit_func);
 extern void	rtnl_register(int protocol, int msgtype,
-			      rtnl_doit_func, rtnl_dumpit_func);
+			      rtnl_doit_func, rtnl_dumpit_func,
+			      rtnl_calcit_func);
 extern int	rtnl_unregister(int protocol, int msgtype);
 extern void	rtnl_unregister_all(int protocol);
 
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index ffb0dc4..6814083 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -218,19 +218,24 @@  int __init br_netlink_init(void)
 	if (err < 0)
 		goto err1;
 
-	err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL, br_dump_ifinfo);
+	err = __rtnl_register(PF_BRIDGE, RTM_GETLINK, NULL,
+			      br_dump_ifinfo, NULL);
 	if (err)
 		goto err2;
-	err = __rtnl_register(PF_BRIDGE, RTM_SETLINK, br_rtm_setlink, NULL);
+	err = __rtnl_register(PF_BRIDGE, RTM_SETLINK,
+			      br_rtm_setlink, NULL, NULL);
 	if (err)
 		goto err3;
-	err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH, br_fdb_add, NULL);
+	err = __rtnl_register(PF_BRIDGE, RTM_NEWNEIGH,
+			      br_fdb_add, NULL, NULL);
 	if (err)
 		goto err3;
-	err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH, br_fdb_delete, NULL);
+	err = __rtnl_register(PF_BRIDGE, RTM_DELNEIGH,
+			      br_fdb_delete, NULL, NULL);
 	if (err)
 		goto err3;
-	err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH, NULL, br_fdb_dump);
+	err = __rtnl_register(PF_BRIDGE, RTM_GETNEIGH,
+			      NULL, br_fdb_dump, NULL);
 	if (err)
 		goto err3;
 
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 008dc70..e7ab0c0 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -740,9 +740,9 @@  static struct pernet_operations fib_rules_net_ops = {
 static int __init fib_rules_init(void)
 {
 	int err;
-	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL);
-	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule);
+	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
 
 	err = register_pernet_subsys(&fib_rules_net_ops);
 	if (err < 0)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 799f06e..ceb505b 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2909,12 +2909,13 @@  EXPORT_SYMBOL(neigh_sysctl_unregister);
 
 static int __init neigh_init(void)
 {
-	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL);
-	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info);
+	rtnl_register(PF_UNSPEC, RTM_NEWNEIGH, neigh_add, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELNEIGH, neigh_delete, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETNEIGH, NULL, neigh_dump_info, NULL);
 
-	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info);
-	rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETNEIGHTBL, NULL, neightbl_dump_info,
+		      NULL);
+	rtnl_register(PF_UNSPEC, RTM_SETNEIGHTBL, neightbl_set, NULL, NULL);
 
 	return 0;
 }
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index abd936d..a798fc6 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -56,9 +56,11 @@ 
 struct rtnl_link {
 	rtnl_doit_func		doit;
 	rtnl_dumpit_func	dumpit;
+	rtnl_calcit_func 	calcit;
 };
 
 static DEFINE_MUTEX(rtnl_mutex);
+static u16 min_ifinfo_dump_size;
 
 void rtnl_lock(void)
 {
@@ -144,12 +146,28 @@  static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
 	return tab ? tab[msgindex].dumpit : NULL;
 }
 
+static rtnl_calcit_func rtnl_get_calcit(int protocol, int msgindex)
+{
+	struct rtnl_link *tab;
+
+	if (protocol <= RTNL_FAMILY_MAX)
+		tab = rtnl_msg_handlers[protocol];
+	else
+		tab = NULL;
+
+	if (tab == NULL || tab[msgindex].calcit == NULL)
+		tab = rtnl_msg_handlers[PF_UNSPEC];
+
+	return tab ? tab[msgindex].calcit : NULL;
+}
+
 /**
  * __rtnl_register - Register a rtnetlink message type
  * @protocol: Protocol family or PF_UNSPEC
  * @msgtype: rtnetlink message type
  * @doit: Function pointer called for each request message
  * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ * @calcit: Function pointer to calc size of dump message
  *
  * Registers the specified function pointers (at least one of them has
  * to be non-NULL) to be called whenever a request message for the
@@ -162,7 +180,8 @@  static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex)
  * Returns 0 on success or a negative error code.
  */
 int __rtnl_register(int protocol, int msgtype,
-		    rtnl_doit_func doit, rtnl_dumpit_func dumpit)
+		    rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+		    rtnl_calcit_func calcit)
 {
 	struct rtnl_link *tab;
 	int msgindex;
@@ -185,6 +204,9 @@  int __rtnl_register(int protocol, int msgtype,
 	if (dumpit)
 		tab[msgindex].dumpit = dumpit;
 
+	if (calcit)
+		tab[msgindex].calcit = calcit;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__rtnl_register);
@@ -199,9 +221,10 @@  EXPORT_SYMBOL_GPL(__rtnl_register);
  * of memory implies no sense in continuing.
  */
 void rtnl_register(int protocol, int msgtype,
-		   rtnl_doit_func doit, rtnl_dumpit_func dumpit)
+		   rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+		   rtnl_calcit_func calcit)
 {
-	if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
+	if (__rtnl_register(protocol, msgtype, doit, dumpit, calcit) < 0)
 		panic("Unable to register rtnetlink message handler, "
 		      "protocol = %d, message type = %d\n",
 		      protocol, msgtype);
@@ -1818,6 +1841,11 @@  static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 	return err;
 }
 
+static u16 rtnl_calcit(struct sk_buff *skb)
+{
+	return min_ifinfo_dump_size;
+}
+
 static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	int idx;
@@ -1847,11 +1875,14 @@  void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
+	size_t if_info_size;
 
-	skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
+	skb = nlmsg_new((if_info_size = if_nlmsg_size(dev)), GFP_KERNEL);
 	if (skb == NULL)
 		goto errout;
 
+	min_ifinfo_dump_size = max_t(u16, if_info_size, min_ifinfo_dump_size);
+
 	err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size() */
@@ -1902,14 +1933,20 @@  static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
 		struct sock *rtnl;
 		rtnl_dumpit_func dumpit;
+		rtnl_calcit_func calcit;
+		u16 min_dump_alloc = 0;
 
 		dumpit = rtnl_get_dumpit(family, type);
 		if (dumpit == NULL)
 			return -EOPNOTSUPP;
+		calcit = rtnl_get_calcit(family, type);
+		if (calcit)
+			min_dump_alloc = calcit(skb);
 
 		__rtnl_unlock();
 		rtnl = net->rtnl;
-		err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
+		err = netlink_dump_start(rtnl, skb, nlh, dumpit,
+					 NULL, min_dump_alloc);
 		rtnl_lock();
 		return err;
 	}
@@ -2019,12 +2056,13 @@  void __init rtnetlink_init(void)
 	netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
 	register_netdevice_notifier(&rtnetlink_dev_notifier);
 
-	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
-	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
-	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
+		      rtnl_dump_ifinfo, rtnl_calcit);
+	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, NULL);
 
-	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
-	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
+	rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all, NULL);
 }
 
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 3609eac..ed1bb8c 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1819,8 +1819,8 @@  static int __init dcbnl_init(void)
 {
 	INIT_LIST_HEAD(&dcb_app_list);
 
-	rtnl_register(PF_UNSPEC, RTM_GETDCB, dcb_doit, NULL);
-	rtnl_register(PF_UNSPEC, RTM_SETDCB, dcb_doit, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETDCB, dcb_doit, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_SETDCB, dcb_doit, NULL, NULL);
 
 	return 0;
 }
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index cf26ac7..3780fd6 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -1414,9 +1414,9 @@  void __init dn_dev_init(void)
 
 	dn_dev_devices_on();
 
-	rtnl_register(PF_DECnet, RTM_NEWADDR, dn_nl_newaddr, NULL);
-	rtnl_register(PF_DECnet, RTM_DELADDR, dn_nl_deladdr, NULL);
-	rtnl_register(PF_DECnet, RTM_GETADDR, NULL, dn_nl_dump_ifaddr);
+	rtnl_register(PF_DECnet, RTM_NEWADDR, dn_nl_newaddr, NULL, NULL);
+	rtnl_register(PF_DECnet, RTM_DELADDR, dn_nl_deladdr, NULL, NULL);
+	rtnl_register(PF_DECnet, RTM_GETADDR, NULL, dn_nl_dump_ifaddr, NULL);
 
 	proc_net_fops_create(&init_net, "decnet_dev", S_IRUGO, &dn_dev_seq_fops);
 
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 1c74ed3..104324d 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -763,8 +763,8 @@  void __init dn_fib_init(void)
 
 	register_dnaddr_notifier(&dn_fib_dnaddr_notifier);
 
-	rtnl_register(PF_DECnet, RTM_NEWROUTE, dn_fib_rtm_newroute, NULL);
-	rtnl_register(PF_DECnet, RTM_DELROUTE, dn_fib_rtm_delroute, NULL);
+	rtnl_register(PF_DECnet, RTM_NEWROUTE, dn_fib_rtm_newroute, NULL, NULL);
+	rtnl_register(PF_DECnet, RTM_DELROUTE, dn_fib_rtm_delroute, NULL, NULL);
 }
 
 
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 74544bc..2949ca4 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1841,10 +1841,11 @@  void __init dn_route_init(void)
 	proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
 
 #ifdef CONFIG_DECNET_ROUTER
-	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, dn_fib_dump);
+	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
+		      dn_fib_dump, NULL);
 #else
 	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
-		      dn_cache_dump);
+		      dn_cache_dump, NULL);
 #endif
 }
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 0d4a184..37b3c18 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1833,8 +1833,8 @@  void __init devinet_init(void)
 
 	rtnl_af_register(&inet_af_ops);
 
-	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL);
-	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL);
-	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr);
+	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL, NULL);
+	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL, NULL);
+	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr, NULL);
 }
 
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 2252471..92fc5f6 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1124,9 +1124,9 @@  static struct pernet_operations fib_net_ops = {
 
 void __init ip_fib_init(void)
 {
-	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL);
-	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL);
-	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib);
+	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL, NULL);
+	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL, NULL);
+	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib, NULL);
 
 	register_pernet_subsys(&fib_net_ops);
 	register_netdevice_notifier(&fib_netdev_notifier);
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 6ffe94c..5ff4765 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -871,7 +871,7 @@  static int inet_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		}
 
 		return netlink_dump_start(idiagnl, skb, nlh,
-					  inet_diag_dump, NULL);
+					  inet_diag_dump, NULL, 0);
 	}
 
 	return inet_diag_get_exact(skb, nlh);
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 30a7763..aae2bd8 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -2544,7 +2544,8 @@  int __init ip_mr_init(void)
 		goto add_proto_fail;
 	}
 #endif
-	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
+	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
+		      NULL, ipmr_rtm_dumproute, NULL);
 	return 0;
 
 #ifdef CONFIG_IP_PIMSM_V2
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 52b0b95..aa29c62 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3295,7 +3295,7 @@  int __init ip_rt_init(void)
 	xfrm_init();
 	xfrm4_init(ip_rt_max_size);
 #endif
-	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
+	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
 
 #ifdef CONFIG_SYSCTL
 	register_pernet_subsys(&sysctl_route_ops);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 498b927..954772b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4692,16 +4692,20 @@  int __init addrconf_init(void)
 	if (err < 0)
 		goto errout_af;
 
-	err = __rtnl_register(PF_INET6, RTM_GETLINK, NULL, inet6_dump_ifinfo);
+	err = __rtnl_register(PF_INET6, RTM_GETLINK, NULL, inet6_dump_ifinfo,
+			      NULL);
 	if (err < 0)
 		goto errout;
 
 	/* Only the first call to __rtnl_register can fail */
-	__rtnl_register(PF_INET6, RTM_NEWADDR, inet6_rtm_newaddr, NULL);
-	__rtnl_register(PF_INET6, RTM_DELADDR, inet6_rtm_deladdr, NULL);
-	__rtnl_register(PF_INET6, RTM_GETADDR, inet6_rtm_getaddr, inet6_dump_ifaddr);
-	__rtnl_register(PF_INET6, RTM_GETMULTICAST, NULL, inet6_dump_ifmcaddr);
-	__rtnl_register(PF_INET6, RTM_GETANYCAST, NULL, inet6_dump_ifacaddr);
+	__rtnl_register(PF_INET6, RTM_NEWADDR, inet6_rtm_newaddr, NULL, NULL);
+	__rtnl_register(PF_INET6, RTM_DELADDR, inet6_rtm_deladdr, NULL, NULL);
+	__rtnl_register(PF_INET6, RTM_GETADDR, inet6_rtm_getaddr,
+			inet6_dump_ifaddr, NULL);
+	__rtnl_register(PF_INET6, RTM_GETMULTICAST, NULL,
+			inet6_dump_ifmcaddr, NULL);
+	__rtnl_register(PF_INET6, RTM_GETANYCAST, NULL,
+			inet6_dump_ifacaddr, NULL);
 
 	ipv6_addr_label_rtnl_register();
 
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index c8993e5..2d8ddba 100644
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c
@@ -592,8 +592,11 @@  out:
 
 void __init ipv6_addr_label_rtnl_register(void)
 {
-	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
-	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
-	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
+	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel,
+			NULL, NULL);
+	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel,
+			NULL, NULL);
+	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get,
+			ip6addrlbl_dump, NULL);
 }
 
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 4076a0b..3030bdf 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1586,7 +1586,8 @@  int __init fib6_init(void)
 	if (ret)
 		goto out_kmem_cache_create;
 
-	ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
+	ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
+			      NULL);
 	if (ret)
 		goto out_unregister_subsys;
 out:
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 82a8099..705c828 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1354,7 +1354,8 @@  int __init ip6_mr_init(void)
 		goto add_proto_fail;
 	}
 #endif
-	rtnl_register(RTNL_FAMILY_IP6MR, RTM_GETROUTE, NULL, ip6mr_rtm_dumproute);
+	rtnl_register(RTNL_FAMILY_IP6MR, RTM_GETROUTE, NULL,
+		      ip6mr_rtm_dumproute, NULL);
 	return 0;
 #ifdef CONFIG_IPV6_PIMSM_V2
 add_proto_fail:
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index de2b1de..216ff31 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2925,9 +2925,9 @@  int __init ip6_route_init(void)
 		goto xfrm6_init;
 
 	ret = -ENOBUFS;
-	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL) ||
-	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL) ||
-	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL))
+	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||
+	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
+	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))
 		goto fib6_rules_init;
 
 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 8041bef..333b0be 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1120,7 +1120,7 @@  ip_set_dump(struct sock *ctnl, struct sk_buff *skb,
 
 	return netlink_dump_start(ctnl, skb, nlh,
 				  ip_set_dump_start,
-				  ip_set_dump_done);
+				  ip_set_dump_done, 0);
 }
 
 /* Add, del and test */
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 482e90c..7dec88a 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -970,7 +970,7 @@  ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 
 	if (nlh->nlmsg_flags & NLM_F_DUMP)
 		return netlink_dump_start(ctnl, skb, nlh, ctnetlink_dump_table,
-					  ctnetlink_done);
+					  ctnetlink_done, 0);
 
 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
 	if (err < 0)
@@ -1840,7 +1840,7 @@  ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
 		return netlink_dump_start(ctnl, skb, nlh,
 					  ctnetlink_exp_dump_table,
-					  ctnetlink_exp_done);
+					  ctnetlink_exp_done, 0);
 	}
 
 	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6ef64ad..0b92f7549 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1659,13 +1659,10 @@  static int netlink_dump(struct sock *sk)
 {
 	struct netlink_sock *nlk = nlk_sk(sk);
 	struct netlink_callback *cb;
-	struct sk_buff *skb;
+	struct sk_buff *skb = NULL;
 	struct nlmsghdr *nlh;
 	int len, err = -ENOBUFS;
-
-	skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
-	if (!skb)
-		goto errout;
+	int alloc_size;
 
 	mutex_lock(nlk->cb_mutex);
 
@@ -1675,6 +1672,12 @@  static int netlink_dump(struct sock *sk)
 		goto errout_skb;
 	}
 
+	alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
+
+	skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL);
+	if (!skb)
+		goto errout;
+
 	len = cb->dump(skb, cb);
 
 	if (len > 0) {
@@ -1721,7 +1724,8 @@  int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 		       const struct nlmsghdr *nlh,
 		       int (*dump)(struct sk_buff *skb,
 				   struct netlink_callback *),
-		       int (*done)(struct netlink_callback *))
+		       int (*done)(struct netlink_callback *),
+		       u16 min_dump_alloc)
 {
 	struct netlink_callback *cb;
 	struct sock *sk;
@@ -1735,6 +1739,7 @@  int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
 	cb->dump = dump;
 	cb->done = done;
 	cb->nlh = nlh;
+	cb->min_dump_alloc = min_dump_alloc;
 	atomic_inc(&skb->users);
 	cb->skb = skb;
 
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 1781d99..482fa57 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -525,7 +525,7 @@  static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 		genl_unlock();
 		err = netlink_dump_start(net->genl_sock, skb, nlh,
-					 ops->dumpit, ops->done);
+					 ops->dumpit, ops->done, 0);
 		genl_lock();
 		return err;
 	}
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index 438accb..d61f676 100644
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -289,15 +289,16 @@  out:
 
 int __init phonet_netlink_register(void)
 {
-	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
+	int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit,
+				  NULL, NULL);
 	if (err)
 		return err;
 
 	/* Further __rtnl_register() cannot fail */
-	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
-	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL);
-	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit);
+	__rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit, NULL);
+	__rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL, NULL);
+	__rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit, NULL);
 	return 0;
 }
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index a606025..2f64262 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -1115,9 +1115,10 @@  nlmsg_failure:
 
 static int __init tc_action_init(void)
 {
-	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
-	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
+	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
+		      NULL);
 
 	return 0;
 }
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index bb2c523..9563887 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -610,10 +610,10 @@  EXPORT_SYMBOL(tcf_exts_dump_stats);
 
 static int __init tc_filter_init(void)
 {
-	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL);
+	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
 	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
-						 tc_dump_tfilter);
+		      tc_dump_tfilter, NULL);
 
 	return 0;
 }
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 6b86276..8182aef 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1792,12 +1792,12 @@  static int __init pktsched_init(void)
 	register_qdisc(&pfifo_head_drop_qdisc_ops);
 	register_qdisc(&mq_qdisc_ops);
 
-	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL);
-	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc);
-	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL);
-	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL);
-	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass);
+	rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, NULL);
+	rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, NULL);
 
 	return 0;
 }
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index c658cb3..0256b8a 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2299,7 +2299,8 @@  static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		if (link->dump == NULL)
 			return -EINVAL;
 
-		return netlink_dump_start(net->xfrm.nlsk, skb, nlh, link->dump, link->done);
+		return netlink_dump_start(net->xfrm.nlsk, skb, nlh,
+					  link->dump, link->done, 0);
 	}
 
 	err = nlmsg_parse(nlh, xfrm_msg_min[type], attrs, XFRMA_MAX,