[NetLabel]: correct usage of RCU locking
This fixes some awkward, and perhaps even problematic, RCU lock usage in the
NetLabel code as well as some other related trivial cleanups found when
looking through the RCU locking. Most of the changes involve removing the
redundant RCU read locks wrapping spinlocks in the case of a RCU writer.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 805a78e6..f18e88b 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -504,22 +504,16 @@
INIT_RCU_HEAD(&doi_def->rcu);
INIT_LIST_HEAD(&doi_def->dom_list);
- rcu_read_lock();
- if (cipso_v4_doi_search(doi_def->doi) != NULL)
- goto doi_add_failure_rlock;
spin_lock(&cipso_v4_doi_list_lock);
if (cipso_v4_doi_search(doi_def->doi) != NULL)
- goto doi_add_failure_slock;
+ goto doi_add_failure;
list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return 0;
-doi_add_failure_slock:
+doi_add_failure:
spin_unlock(&cipso_v4_doi_list_lock);
-doi_add_failure_rlock:
- rcu_read_unlock();
return -EEXIST;
}
@@ -543,29 +537,23 @@
struct cipso_v4_doi *doi_def;
struct cipso_v4_domhsh_entry *dom_iter;
- rcu_read_lock();
- if (cipso_v4_doi_search(doi) != NULL) {
- spin_lock(&cipso_v4_doi_list_lock);
- doi_def = cipso_v4_doi_search(doi);
- if (doi_def == NULL) {
- spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
- return -ENOENT;
- }
+ spin_lock(&cipso_v4_doi_list_lock);
+ doi_def = cipso_v4_doi_search(doi);
+ if (doi_def != NULL) {
doi_def->valid = 0;
list_del_rcu(&doi_def->list);
spin_unlock(&cipso_v4_doi_list_lock);
+ rcu_read_lock();
list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list)
if (dom_iter->valid)
netlbl_domhsh_remove(dom_iter->domain,
audit_info);
- cipso_v4_cache_invalidate();
rcu_read_unlock();
-
+ cipso_v4_cache_invalidate();
call_rcu(&doi_def->rcu, callback);
return 0;
}
- rcu_read_unlock();
+ spin_unlock(&cipso_v4_doi_list_lock);
return -ENOENT;
}
@@ -653,22 +641,19 @@
new_dom->valid = 1;
INIT_RCU_HEAD(&new_dom->rcu);
- rcu_read_lock();
spin_lock(&cipso_v4_doi_list_lock);
- list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
+ list_for_each_entry(iter, &doi_def->dom_list, list)
if (iter->valid &&
((domain != NULL && iter->domain != NULL &&
strcmp(iter->domain, domain) == 0) ||
(domain == NULL && iter->domain == NULL))) {
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
kfree(new_dom->domain);
kfree(new_dom);
return -EEXIST;
}
list_add_tail_rcu(&new_dom->list, &doi_def->dom_list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return 0;
}
@@ -689,9 +674,8 @@
{
struct cipso_v4_domhsh_entry *iter;
- rcu_read_lock();
spin_lock(&cipso_v4_doi_list_lock);
- list_for_each_entry_rcu(iter, &doi_def->dom_list, list)
+ list_for_each_entry(iter, &doi_def->dom_list, list)
if (iter->valid &&
((domain != NULL && iter->domain != NULL &&
strcmp(iter->domain, domain) == 0) ||
@@ -699,13 +683,10 @@
iter->valid = 0;
list_del_rcu(&iter->list);
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
call_rcu(&iter->rcu, cipso_v4_doi_domhsh_free);
-
return 0;
}
spin_unlock(&cipso_v4_doi_list_lock);
- rcu_read_unlock();
return -ENOENT;
}