sunrpc: Pass lockdep expression to RCU lists

detail->hash_table[] is traversed using hlist_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of detail->hash_lock.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index bd843a8..8a8e352 100644 (file)
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -113,7 +113,8 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
        spin_lock(&detail->hash_lock);
 
        /* check if entry appeared while we slept */
-       hlist_for_each_entry_rcu(tmp, head, cache_list) {
+       hlist_for_each_entry_rcu(tmp, head, cache_list,
+                                lockdep_is_held(&detail->hash_lock)) {
                if (detail->match(tmp, key)) {
                        if (cache_is_expired(detail, tmp)) {
                                sunrpc_begin_cache_remove_entry(tmp, detail);