1 files changed, 19 insertions, 22 deletions

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 06f24ff08ac..624a0b7c05e 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -23,7 +23,6 @@
 #include <linux/hash.h>
 #include <linux/random.h>
 #include <linux/rhashtable.h>
-#include <linux/log2.h>
 
 #define HASH_DEFAULT_SIZE	64UL
 #define HASH_MIN_SIZE		4UL
@@ -38,16 +37,10 @@ int lockdep_rht_mutex_is_held(const struct rhashtable *ht)
 EXPORT_SYMBOL_GPL(lockdep_rht_mutex_is_held);
 #endif
 
-/**
- * rht_obj - cast hash head to outer object
- * @ht:		hash table
- * @he:		hashed node
- */
-void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he)
+static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he)
 {
 	return (void *) he - ht->p.head_offset;
 }
-EXPORT_SYMBOL_GPL(rht_obj);
 
 static u32 __hashfn(const struct rhashtable *ht, const void *key,
 		      u32 len, u32 hsize)
@@ -237,7 +230,7 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags)
 	ht->shift++;
 
 	/* For each new bucket, search the corresponding old bucket
-	 * for the first entry that hashes to the new bucket, and
+	 * for the first entry that hashes to the new bucket, and
 	 * link the new bucket to that entry. Since all the entries
 	 * which will end up in the new bucket appear in the same
 	 * old bucket, this constructs an entirely valid new hash
@@ -255,8 +248,8 @@ int rhashtable_expand(struct rhashtable *ht, gfp_t flags)
 	}
 
 	/* Publish the new table pointer. Lookups may now traverse
-	 * the new table, but they will not benefit from any
-	 * additional efficiency until later steps unzip the buckets.
+	 * the new table, but they will not benefit from any
+	 * additional efficiency until later steps unzip the buckets.
 	 */
 	rcu_assign_pointer(ht->tbl, new_tbl);
 
@@ -304,7 +297,7 @@ int rhashtable_shrink(struct rhashtable *ht, gfp_t flags)
 
 	ASSERT_RHT_MUTEX(ht);
 
-	if (tbl->size <= HASH_MIN_SIZE)
+	if (ht->shift <= ht->p.min_shift)
 		return 0;
 
 	ntbl = bucket_table_alloc(tbl->size / 2, flags);
@@ -313,14 +306,14 @@ int rhashtable_shrink(struct rhashtable *ht, gfp_t flags)
 
 	ht->shift--;
 
-	/* Link each bucket in the new table to the first bucket
+	/* Link each bucket in the new table to the first bucket
 	 * in the old table that contains entries which will hash
 	 * to the new bucket.
 	 */
 	for (i = 0; i < ntbl->size; i++) {
 		ntbl->buckets[i] = tbl->buckets[i];
 
-		/* Link each bucket in the new table to the first bucket
+		/* Link each bucket in the new table to the first bucket
 		 * in the old table that contains entries which will hash
 		 * to the new bucket.
 		 */
@@ -386,7 +379,7 @@ EXPORT_SYMBOL_GPL(rhashtable_insert);
  * deletion when combined with walking or lookup.
  */
 void rhashtable_remove_pprev(struct rhashtable *ht, struct rhash_head *obj,
-			     struct rhash_head **pprev, gfp_t flags)
+			     struct rhash_head __rcu **pprev, gfp_t flags)
 {
 	struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
 
@@ -512,9 +505,10 @@ void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash,
 }
 EXPORT_SYMBOL_GPL(rhashtable_lookup_compare);
 
-static size_t rounded_hashtable_size(unsigned int nelem)
+static size_t rounded_hashtable_size(struct rhashtable_params *params)
 {
-	return max(roundup_pow_of_two(nelem * 4 / 3), HASH_MIN_SIZE);
+	return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
+		   1UL << params->min_shift);
 }
 
 /**
@@ -572,8 +566,11 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
 	    (!params->key_len && !params->obj_hashfn))
 		return -EINVAL;
 
+	params->min_shift = max_t(size_t, params->min_shift,
+				  ilog2(HASH_MIN_SIZE));
+
 	if (params->nelem_hint)
-		size = rounded_hashtable_size(params->nelem_hint);
+		size = rounded_hashtable_size(params);
 
 	tbl = bucket_table_alloc(size, GFP_KERNEL);
 	if (tbl == NULL)
@@ -595,13 +592,13 @@ EXPORT_SYMBOL_GPL(rhashtable_init);
  * rhashtable_destroy - destroy hash table
  * @ht:		the hash table to destroy
  *
- * Frees the bucket array.
+ * Frees the bucket array. This function is not rcu safe, therefore the caller
+ * has to make sure that no resizing may happen by unpublishing the hashtable
+ * and waiting for the quiescent cycle before releasing the bucket array.
  */
 void rhashtable_destroy(const struct rhashtable *ht)
 {
-	const struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
-
-	bucket_table_free(tbl);
+	bucket_table_free(ht->tbl);
 }
 EXPORT_SYMBOL_GPL(rhashtable_destroy);