rhashtable: silence RCU warning in rhashtable_test.

print_ht in rhashtable_test calls rht_dereference() with neither
RCU protection or the mutex.  This triggers an RCU warning.
So take the mutex to silence the warning.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index fb6968109113..6ca59ffcacbe 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -501,6 +501,8 @@ static unsigned int __init print_ht(struct rhltable *rhlt)
         unsigned int i, cnt = 0;
 
         ht = &rhlt->ht;
+        /* Take the mutex to avoid RCU warning */
+        mutex_lock(&ht->mutex);
         tbl = rht_dereference(ht->tbl, ht);
         for (i = 0; i < tbl->size; i++) {
                 struct rhash_head *pos, *next;
@@ -534,6 +536,7 @@ static unsigned int __init print_ht(struct rhltable *rhlt)
                 }
         }
         printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
+        mutex_unlock(&ht->mutex);
 
         return cnt;
 }