forked from mirrors/linux
tipc: convert name table read-write lock to RCU
Convert tipc name table read-write lock to RCU. After this change, a new spin lock is used to protect name table on write side while RCU is applied on read side. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ying Xue
David S. Miller
parent
834caafa3e
commit
97ede29e80
4 changed files with 69 additions and 59 deletions
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@ -542,6 +542,15 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n,
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pos = hlist_entry_safe(rcu_dereference_bh((pos)->member.next),\
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typeof(*(pos)), member))
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/**
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* hlist_for_each_entry_from_rcu - iterate over a hlist continuing from current point
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* @pos: the type * to use as a loop cursor.
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* @member: the name of the hlist_node within the struct.
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*/
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#define hlist_for_each_entry_from_rcu(pos, member) \
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for (; pos; \
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pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\
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typeof(*(pos)), member))
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#endif /* __KERNEL__ */
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#endif
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@ -113,8 +113,8 @@ struct sk_buff *tipc_named_publish(struct publication *publ)
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struct sk_buff *buf;
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struct distr_item *item;
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list_add_tail(&publ->local_list,
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&tipc_nametbl->publ_list[publ->scope]);
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list_add_tail_rcu(&publ->local_list,
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&tipc_nametbl->publ_list[publ->scope]);
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if (publ->scope == TIPC_NODE_SCOPE)
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return NULL;
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@ -208,12 +208,12 @@ void tipc_named_node_up(u32 dnode)
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__skb_queue_head_init(&head);
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read_lock_bh(&tipc_nametbl_lock);
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rcu_read_lock();
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named_distribute(&head, dnode,
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&tipc_nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
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named_distribute(&head, dnode,
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&tipc_nametbl->publ_list[TIPC_ZONE_SCOPE]);
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read_unlock_bh(&tipc_nametbl_lock);
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rcu_read_unlock();
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tipc_link_xmit(&head, dnode, dnode);
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}
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@ -260,12 +260,12 @@ static void tipc_publ_purge(struct publication *publ, u32 addr)
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{
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struct publication *p;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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p = tipc_nametbl_remove_publ(publ->type, publ->lower,
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publ->node, publ->ref, publ->key);
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if (p)
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tipc_publ_unsubscribe(p, addr);
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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if (p != publ) {
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pr_err("Unable to remove publication from failed node\n"
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@ -274,7 +274,7 @@ static void tipc_publ_purge(struct publication *publ, u32 addr)
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publ->key);
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}
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kfree(p);
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kfree_rcu(p, rcu);
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}
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void tipc_publ_notify(struct list_head *nsub_list, u32 addr)
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@ -311,7 +311,7 @@ static bool tipc_update_nametbl(struct distr_item *i, u32 node, u32 dtype)
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ntohl(i->key));
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if (publ) {
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tipc_publ_unsubscribe(publ, node);
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kfree(publ);
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kfree_rcu(publ, rcu);
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return true;
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}
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} else {
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@ -376,14 +376,14 @@ void tipc_named_rcv(struct sk_buff *buf)
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u32 count = msg_data_sz(msg) / ITEM_SIZE;
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u32 node = msg_orignode(msg);
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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while (count--) {
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if (!tipc_update_nametbl(item, node, msg_type(msg)))
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tipc_named_add_backlog(item, msg_type(msg), node);
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item++;
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}
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tipc_named_process_backlog();
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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kfree_skb(buf);
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}
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@ -399,12 +399,12 @@ void tipc_named_reinit(void)
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struct publication *publ;
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int scope;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
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list_for_each_entry(publ, &tipc_nametbl->publ_list[scope],
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local_list)
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list_for_each_entry_rcu(publ, &tipc_nametbl->publ_list[scope],
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local_list)
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publ->node = tipc_own_addr;
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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}
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@ -92,6 +92,7 @@ struct sub_seq {
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* @ns_list: links to adjacent name sequences in hash chain
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* @subscriptions: list of subscriptions for this 'type'
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* @lock: spinlock controlling access to publication lists of all sub-sequences
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* @rcu: RCU callback head used for deferred freeing
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*/
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struct name_seq {
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u32 type;
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@ -101,10 +102,11 @@ struct name_seq {
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struct hlist_node ns_list;
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struct list_head subscriptions;
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spinlock_t lock;
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struct rcu_head rcu;
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};
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struct name_table *tipc_nametbl;
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DEFINE_RWLOCK(tipc_nametbl_lock);
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DEFINE_SPINLOCK(tipc_nametbl_lock);
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static int hash(int x)
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{
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@ -166,7 +168,7 @@ static struct name_seq *tipc_nameseq_create(u32 type, struct hlist_head *seq_hea
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nseq->alloc = 1;
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INIT_HLIST_NODE(&nseq->ns_list);
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INIT_LIST_HEAD(&nseq->subscriptions);
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hlist_add_head(&nseq->ns_list, seq_head);
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hlist_add_head_rcu(&nseq->ns_list, seq_head);
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return nseq;
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}
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@ -451,7 +453,7 @@ static struct name_seq *nametbl_find_seq(u32 type)
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struct name_seq *ns;
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seq_head = &tipc_nametbl->seq_hlist[hash(type)];
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hlist_for_each_entry(ns, seq_head, ns_list) {
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hlist_for_each_entry_rcu(ns, seq_head, ns_list) {
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if (ns->type == type)
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return ns;
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}
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@ -498,10 +500,10 @@ struct publication *tipc_nametbl_remove_publ(u32 type, u32 lower,
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spin_lock_bh(&seq->lock);
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publ = tipc_nameseq_remove_publ(seq, lower, node, ref, key);
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if (!seq->first_free && list_empty(&seq->subscriptions)) {
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hlist_del_init(&seq->ns_list);
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spin_unlock_bh(&seq->lock);
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hlist_del_init_rcu(&seq->ns_list);
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kfree(seq->sseqs);
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kfree(seq);
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spin_unlock_bh(&seq->lock);
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kfree_rcu(seq, rcu);
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return publ;
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}
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spin_unlock_bh(&seq->lock);
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@ -533,7 +535,7 @@ u32 tipc_nametbl_translate(u32 type, u32 instance, u32 *destnode)
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if (!tipc_in_scope(*destnode, tipc_own_addr))
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return 0;
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read_lock_bh(&tipc_nametbl_lock);
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rcu_read_lock();
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seq = nametbl_find_seq(type);
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if (unlikely(!seq))
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goto not_found;
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@ -590,7 +592,7 @@ u32 tipc_nametbl_translate(u32 type, u32 instance, u32 *destnode)
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no_match:
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spin_unlock_bh(&seq->lock);
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not_found:
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read_unlock_bh(&tipc_nametbl_lock);
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rcu_read_unlock();
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*destnode = node;
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return ref;
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}
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@ -616,7 +618,7 @@ int tipc_nametbl_mc_translate(u32 type, u32 lower, u32 upper, u32 limit,
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struct name_info *info;
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int res = 0;
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read_lock_bh(&tipc_nametbl_lock);
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rcu_read_lock();
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seq = nametbl_find_seq(type);
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if (!seq)
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goto exit;
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@ -641,7 +643,7 @@ int tipc_nametbl_mc_translate(u32 type, u32 lower, u32 upper, u32 limit,
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}
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spin_unlock_bh(&seq->lock);
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exit:
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read_unlock_bh(&tipc_nametbl_lock);
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rcu_read_unlock();
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return res;
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}
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@ -654,11 +656,11 @@ struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
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struct publication *publ;
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struct sk_buff *buf = NULL;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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if (tipc_nametbl->local_publ_count >= TIPC_MAX_PUBLICATIONS) {
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pr_warn("Publication failed, local publication limit reached (%u)\n",
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TIPC_MAX_PUBLICATIONS);
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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return NULL;
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}
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@ -670,7 +672,7 @@ struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
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/* Any pending external events? */
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tipc_named_process_backlog();
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}
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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if (buf)
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named_cluster_distribute(buf);
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@ -685,7 +687,7 @@ int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
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struct publication *publ;
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struct sk_buff *skb = NULL;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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publ = tipc_nametbl_remove_publ(type, lower, tipc_own_addr, ref, key);
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if (likely(publ)) {
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tipc_nametbl->local_publ_count--;
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@ -693,13 +695,13 @@ int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
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/* Any pending external events? */
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tipc_named_process_backlog();
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list_del_init(&publ->pport_list);
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kfree(publ);
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kfree_rcu(publ, rcu);
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} else {
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pr_err("Unable to remove local publication\n"
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"(type=%u, lower=%u, ref=%u, key=%u)\n",
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type, lower, ref, key);
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}
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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if (skb) {
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named_cluster_distribute(skb);
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@ -717,7 +719,7 @@ void tipc_nametbl_subscribe(struct tipc_subscription *s)
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int index = hash(type);
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struct name_seq *seq;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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seq = nametbl_find_seq(type);
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if (!seq)
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seq = tipc_nameseq_create(type,
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@ -730,7 +732,7 @@ void tipc_nametbl_subscribe(struct tipc_subscription *s)
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pr_warn("Failed to create subscription for {%u,%u,%u}\n",
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s->seq.type, s->seq.lower, s->seq.upper);
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}
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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}
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/**
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@ -740,24 +742,23 @@ void tipc_nametbl_unsubscribe(struct tipc_subscription *s)
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{
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struct name_seq *seq;
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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seq = nametbl_find_seq(s->seq.type);
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if (seq != NULL) {
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spin_lock_bh(&seq->lock);
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list_del_init(&s->nameseq_list);
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if (!seq->first_free && list_empty(&seq->subscriptions)) {
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hlist_del_init(&seq->ns_list);
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spin_unlock_bh(&seq->lock);
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hlist_del_init_rcu(&seq->ns_list);
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kfree(seq->sseqs);
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kfree(seq);
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spin_unlock_bh(&seq->lock);
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kfree_rcu(seq, rcu);
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} else {
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spin_unlock_bh(&seq->lock);
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}
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}
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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}
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/**
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* subseq_list - print specified sub-sequence contents into the given buffer
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*/
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@ -880,7 +881,7 @@ static int nametbl_list(char *buf, int len, u32 depth_info,
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upbound = ~0;
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for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
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seq_head = &tipc_nametbl->seq_hlist[i];
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hlist_for_each_entry(seq, seq_head, ns_list) {
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hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
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ret += nameseq_list(seq, buf + ret, len - ret,
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depth, seq->type,
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lowbound, upbound, i);
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@ -896,7 +897,7 @@ static int nametbl_list(char *buf, int len, u32 depth_info,
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ret += nametbl_header(buf + ret, len - ret, depth);
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i = hash(type);
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seq_head = &tipc_nametbl->seq_hlist[i];
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hlist_for_each_entry(seq, seq_head, ns_list) {
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hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
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if (seq->type == type) {
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ret += nameseq_list(seq, buf + ret, len - ret,
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depth, type,
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@ -928,11 +929,11 @@ struct sk_buff *tipc_nametbl_get(const void *req_tlv_area, int req_tlv_space)
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pb = TLV_DATA(rep_tlv);
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pb_len = ULTRA_STRING_MAX_LEN;
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argv = (struct tipc_name_table_query *)TLV_DATA(req_tlv_area);
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read_lock_bh(&tipc_nametbl_lock);
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rcu_read_lock();
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str_len = nametbl_list(pb, pb_len, ntohl(argv->depth),
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ntohl(argv->type),
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ntohl(argv->lowbound), ntohl(argv->upbound));
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read_unlock_bh(&tipc_nametbl_lock);
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rcu_read_unlock();
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str_len += 1; /* for "\0" */
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skb_put(buf, TLV_SPACE(str_len));
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TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
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@ -974,13 +975,13 @@ static void tipc_purge_publications(struct name_seq *seq)
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list_for_each_entry_safe(publ, safe, &info->zone_list, zone_list) {
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tipc_nametbl_remove_publ(publ->type, publ->lower, publ->node,
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publ->ref, publ->key);
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kfree(publ);
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kfree_rcu(publ, rcu);
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}
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hlist_del_init(&seq->ns_list);
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hlist_del_init_rcu(&seq->ns_list);
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kfree(seq->sseqs);
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spin_lock_bh(&seq->lock);
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kfree(seq->sseqs);
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kfree(seq);
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kfree_rcu(seq, rcu);
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}
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void tipc_nametbl_stop(void)
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@ -988,22 +989,22 @@ void tipc_nametbl_stop(void)
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u32 i;
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struct name_seq *seq;
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struct hlist_head *seq_head;
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struct hlist_node *safe;
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/* Verify name table is empty and purge any lingering
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* publications, then release the name table
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*/
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write_lock_bh(&tipc_nametbl_lock);
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spin_lock_bh(&tipc_nametbl_lock);
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for (i = 0; i < TIPC_NAMETBL_SIZE; i++) {
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if (hlist_empty(&tipc_nametbl->seq_hlist[i]))
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continue;
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seq_head = &tipc_nametbl->seq_hlist[i];
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hlist_for_each_entry_safe(seq, safe, seq_head, ns_list) {
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hlist_for_each_entry_rcu(seq, seq_head, ns_list) {
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tipc_purge_publications(seq);
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}
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}
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write_unlock_bh(&tipc_nametbl_lock);
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spin_unlock_bh(&tipc_nametbl_lock);
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synchronize_net();
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kfree(tipc_nametbl);
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}
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@ -1109,7 +1110,7 @@ static int __tipc_nl_seq_list(struct tipc_nl_msg *msg, u32 *last_type,
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u32 *last_lower, u32 *last_publ)
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{
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struct hlist_head *seq_head;
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struct name_seq *seq;
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struct name_seq *seq = NULL;
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int err;
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int i;
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@ -1126,13 +1127,13 @@ static int __tipc_nl_seq_list(struct tipc_nl_msg *msg, u32 *last_type,
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if (!seq)
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return -EPIPE;
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} else {
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seq = hlist_entry_safe((seq_head)->first,
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struct name_seq, ns_list);
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hlist_for_each_entry_rcu(seq, seq_head, ns_list)
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break;
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if (!seq)
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continue;
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}
|
||||
|
||||
hlist_for_each_entry_from(seq, ns_list) {
|
||||
hlist_for_each_entry_from_rcu(seq, ns_list) {
|
||||
spin_lock_bh(&seq->lock);
|
||||
err = __tipc_nl_subseq_list(msg, seq, last_lower,
|
||||
last_publ);
|
||||
|
|
@ -1165,8 +1166,7 @@ int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
|
|||
msg.portid = NETLINK_CB(cb->skb).portid;
|
||||
msg.seq = cb->nlh->nlmsg_seq;
|
||||
|
||||
read_lock_bh(&tipc_nametbl_lock);
|
||||
|
||||
rcu_read_lock();
|
||||
err = __tipc_nl_seq_list(&msg, &last_type, &last_lower, &last_publ);
|
||||
if (!err) {
|
||||
done = 1;
|
||||
|
|
@ -1179,8 +1179,7 @@ int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
|
|||
*/
|
||||
cb->prev_seq = 1;
|
||||
}
|
||||
|
||||
read_unlock_bh(&tipc_nametbl_lock);
|
||||
rcu_read_unlock();
|
||||
|
||||
cb->args[0] = last_type;
|
||||
cb->args[1] = last_lower;
|
||||
|
|
|
|||
|
|
@ -62,6 +62,7 @@ struct tipc_port_list;
|
|||
* @node_list: adjacent matching name seq publications with >= node scope
|
||||
* @cluster_list: adjacent matching name seq publications with >= cluster scope
|
||||
* @zone_list: adjacent matching name seq publications with >= zone scope
|
||||
* @rcu: RCU callback head used for deferred freeing
|
||||
*
|
||||
* Note that the node list, cluster list, and zone list are circular lists.
|
||||
*/
|
||||
|
|
@ -79,6 +80,7 @@ struct publication {
|
|||
struct list_head node_list;
|
||||
struct list_head cluster_list;
|
||||
struct list_head zone_list;
|
||||
struct rcu_head rcu;
|
||||
};
|
||||
|
||||
/**
|
||||
|
|
@ -93,7 +95,7 @@ struct name_table {
|
|||
u32 local_publ_count;
|
||||
};
|
||||
|
||||
extern rwlock_t tipc_nametbl_lock;
|
||||
extern spinlock_t tipc_nametbl_lock;
|
||||
extern struct name_table *tipc_nametbl;
|
||||
|
||||
int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb);
|
||||
|
|
|
|||
Loading…
Reference in a new issue