powerpc/64s/hash: Fix hash_preload running with interrupts enabled

[linux-2.6-microblaze.git] / lib / rhashtable.c

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index bdb7e4c..9f6890a 100644 (file)
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -63,13 +63,22 @@ EXPORT_SYMBOL_GPL(lockdep_rht_bucket_is_held);
 #define ASSERT_RHT_MUTEX(HT)
 #endif
 
+static inline union nested_table *nested_table_top(
+       const struct bucket_table *tbl)
+{
+       /* The top-level bucket entry does not need RCU protection
+        * because it's set at the same time as tbl->nest.
+        */
+       return (void *)rcu_dereference_protected(tbl->buckets[0], 1);
+}
+
 static void nested_table_free(union nested_table *ntbl, unsigned int size)
 {
        const unsigned int shift = PAGE_SHIFT - ilog2(sizeof(void *));
        const unsigned int len = 1 << shift;
        unsigned int i;
 
-       ntbl = rcu_dereference_raw(ntbl->table);
+       ntbl = rcu_dereference_protected(ntbl->table, 1);
        if (!ntbl)
                return;
 
@@ -89,7 +98,7 @@ static void nested_bucket_table_free(const struct bucket_table *tbl)
        union nested_table *ntbl;
        unsigned int i;
 
-       ntbl = (union nested_table *)rcu_dereference_raw(tbl->buckets[0]);
+       ntbl = nested_table_top(tbl);
 
        for (i = 0; i < len; i++)
                nested_table_free(ntbl + i, size);
@@ -1173,7 +1182,7 @@ struct rhash_lock_head **__rht_bucket_nested(const struct bucket_table *tbl,
        unsigned int subhash = hash;
        union nested_table *ntbl;
 
-       ntbl = (union nested_table *)rcu_dereference_raw(tbl->buckets[0]);
+       ntbl = nested_table_top(tbl);
        ntbl = rht_dereference_bucket_rcu(ntbl[index].table, tbl, hash);
        subhash >>= tbl->nest;
 
@@ -1213,7 +1222,7 @@ struct rhash_lock_head **rht_bucket_nested_insert(struct rhashtable *ht,
        unsigned int size = tbl->size >> tbl->nest;
        union nested_table *ntbl;
 
-       ntbl = (union nested_table *)rcu_dereference_raw(tbl->buckets[0]);
+       ntbl = nested_table_top(tbl);
        hash >>= tbl->nest;
        ntbl = nested_table_alloc(ht, &ntbl[index].table,
                                  size <= (1 << shift));