[PATCH 2/3] netlink: Mark dumps as inconsistent which have been interrupted by a resize
From: Thomas Graf <tgraf@suug.ch>
Date: 2015-01-20 13:20:26
Also in:
netfilter-devel
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
A deferred resize of nl_table causes the offsets that Netlink diag keeps to become inaccurate. Mark the dump as inconsistent and have user space request a new dump. Signed-off-by: Thomas Graf <tgraf@suug.ch> --- net/netlink/af_netlink.c | 10 ++++++++++ net/netlink/af_netlink.h | 1 + net/netlink/diag.c | 1 + 3 files changed, 12 insertions(+)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7a94185..e214557 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c@@ -91,6 +91,9 @@ static inline int netlink_is_kernel(struct sock *sk) struct netlink_table *nl_table; EXPORT_SYMBOL_GPL(nl_table); +atomic_t nl_table_seq; +EXPORT_SYMBOL_GPL(nl_table_seq); + static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); static int netlink_dump(struct sock *sk);
@@ -3071,6 +3074,12 @@ static const struct net_proto_family netlink_family_ops = { .owner = THIS_MODULE, /* for consistency 8) */ }; +static void nl_table_resize_notify(const struct rhashtable *ht, + enum rht_resize_op op) +{ + atomic_inc(&nl_table_seq); +} + static int __net_init netlink_net_init(struct net *net) { #ifdef CONFIG_PROC_FS
@@ -3124,6 +3133,7 @@ static int __init netlink_proto_init(void) .max_shift = 16, /* 64K */ .grow_decision = rht_grow_above_75, .shrink_decision = rht_shrink_below_30, + .resize_notify = nl_table_resize_notify, }; if (err != 0)
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index 7518375..51c23c0 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h@@ -74,5 +74,6 @@ struct netlink_table { extern struct netlink_table *nl_table; extern rwlock_t nl_table_lock; +extern atomic_t nl_table_seq; #endif
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index 3ee63a3..50aa385 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c@@ -112,6 +112,7 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, int ret = 0, num = 0, i; req = nlmsg_data(cb->nlh); + cb->seq = atomic_read(&nl_table_seq); for (i = 0; i < htbl->size; i++) { struct rhash_head *pos;
--
1.9.3