Red Hat INTERNAL-ONLY kernel discussion list <rhkernel-list@redhat.com>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: 2015-05-14 05:56:45
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Thu, May 14, 2015 at 12:21:51PM +0800, Herbert Xu wrote:
If that was the case then we simply need to get rid of dynamic rehashing.
Here is a totally untested patch against 4.0.
---8<---
The current rhashtable rehash code is buggy and can't deal with
parallel insertions/removals without corrupting the hash table.
This patch disables it by partially reverting
c5adde9468b0714a051eac7f9666f23eb10b61f7 ("netlink: eliminate
nl_sk_hash_lock").
This patch also removes a bogus socket lock introduced by that
very same patch.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 05919bf..322fe03 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c@@ -1052,7 +1052,7 @@ static int netlink_insert(struct sock *sk, u32 portid) struct netlink_table *table = &nl_table[sk->sk_protocol]; int err; - lock_sock(sk); + mutex_lock(&table->hash.mutex); err = -EBUSY; if (nlk_sk(sk)->portid)
@@ -1073,7 +1073,7 @@ static int netlink_insert(struct sock *sk, u32 portid) } err: - release_sock(sk); + mutex_unlock(&table->hash.mutex); return err; }
@@ -1082,10 +1082,12 @@ static void netlink_remove(struct sock *sk) struct netlink_table *table; table = &nl_table[sk->sk_protocol]; + mutex_lock(&table->hash.mutex); if (rhashtable_remove(&table->hash, &nlk_sk(sk)->node)) { WARN_ON(atomic_read(&sk->sk_refcnt) == 1); __sock_put(sk); } + mutex_unlock(&table->hash.mutex); netlink_table_grab(); if (nlk_sk(sk)->subscriptions) {
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt