From d6e164e3215794f9920af69cd2c6794632773478 Mon Sep 17 00:00:00 2001 From: Richard Alpe Date: Fri, 16 Jan 2015 12:30:40 +0100 Subject: [PATCH] tipc: fix socket list regression in new nl api Commit 07f6c4bc (tipc: convert tipc reference table to use generic rhashtable) introduced a problem with port listing in the new netlink API. It broke the resume functionality resulting in a never ending loop. This was caused by starting with the first hash table every time subsequently never returning an empty skb (terminating). This patch fixes the resume mechanism by keeping a logical reference to the last hash table along with a logical reference to the socket (port) that didn't fit in the previous message. Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/socket.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 720fda6cc2e6..679a22082fcb 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2749,29 +2749,35 @@ int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb) struct tipc_sock *tsk; const struct bucket_table *tbl; struct rhash_head *pos; - u32 prev_portid = cb->args[0]; - u32 portid = prev_portid; struct net *net = sock_net(skb->sk); struct tipc_net *tn = net_generic(net, tipc_net_id); - int i; + u32 tbl_id = cb->args[0]; + u32 prev_portid = cb->args[1]; rcu_read_lock(); tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht); - for (i = 0; i < tbl->size; i++) { - rht_for_each_entry_rcu(tsk, pos, tbl, i, node) { + for (; tbl_id < tbl->size; tbl_id++) { + rht_for_each_entry_rcu(tsk, pos, tbl, tbl_id, node) { spin_lock_bh(&tsk->sk.sk_lock.slock); - portid = tsk->portid; - err = __tipc_nl_add_sk(skb, cb, tsk); - spin_unlock_bh(&tsk->sk.sk_lock.slock); - if (err) - break; + if (prev_portid && prev_portid != tsk->portid) { + spin_unlock_bh(&tsk->sk.sk_lock.slock); + continue; + } - prev_portid = portid; + err = __tipc_nl_add_sk(skb, cb, tsk); + if (err) { + prev_portid = tsk->portid; + spin_unlock_bh(&tsk->sk.sk_lock.slock); + goto out; + } + prev_portid = 0; + spin_unlock_bh(&tsk->sk.sk_lock.slock); } } +out: rcu_read_unlock(); - - cb->args[0] = prev_portid; + cb->args[0] = tbl_id; + cb->args[1] = prev_portid; return skb->len; }