From 988dfbd795cf08b00576c1ced4210281b2bccffc Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 10 Mar 2015 09:27:55 +1100 Subject: rhashtable: Move hash_rnd into bucket_table Currently hash_rnd is a parameter that users can set. However, no existing users set this parameter. It is also something that people are unlikely to want to set directly since it's just a random number. In preparation for allowing the reseeding/rehashing of rhashtable, this patch moves hash_rnd into bucket_table so that it's now an internal state rather than a parameter. Signed-off-by: Herbert Xu Acked-by: Thomas Graf Signed-off-by: David S. Miller --- lib/rhashtable.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'lib/rhashtable.c') diff --git a/lib/rhashtable.c b/lib/rhashtable.c index b5344ef4c684..ba15dceee27f 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -66,25 +66,28 @@ static u32 rht_bucket_index(const struct bucket_table *tbl, u32 hash) return hash & (tbl->size - 1); } -static u32 obj_raw_hashfn(const struct rhashtable *ht, const void *ptr) +static u32 obj_raw_hashfn(struct rhashtable *ht, const void *ptr) { + struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); u32 hash; if (unlikely(!ht->p.key_len)) - hash = ht->p.obj_hashfn(ptr, ht->p.hash_rnd); + hash = ht->p.obj_hashfn(ptr, tbl->hash_rnd); else hash = ht->p.hashfn(ptr + ht->p.key_offset, ht->p.key_len, - ht->p.hash_rnd); + tbl->hash_rnd); return hash >> HASH_RESERVED_SPACE; } static u32 key_hashfn(struct rhashtable *ht, const void *key, u32 len) { - return ht->p.hashfn(key, len, ht->p.hash_rnd) >> HASH_RESERVED_SPACE; + struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); + + return ht->p.hashfn(key, len, tbl->hash_rnd) >> HASH_RESERVED_SPACE; } -static u32 head_hashfn(const struct rhashtable *ht, +static u32 head_hashfn(struct rhashtable *ht, const struct bucket_table *tbl, const struct rhash_head *he) { @@ -92,7 +95,7 @@ static u32 head_hashfn(const struct rhashtable *ht, } #ifdef CONFIG_PROVE_LOCKING -static void debug_dump_buckets(const struct rhashtable *ht, +static void debug_dump_buckets(struct rhashtable *ht, const struct bucket_table *tbl) { struct rhash_head *he; @@ -385,6 +388,8 @@ int rhashtable_expand(struct rhashtable *ht) if (new_tbl == NULL) return -ENOMEM; + new_tbl->hash_rnd = old_tbl->hash_rnd; + atomic_inc(&ht->shift); /* Make insertions go into the new, empty table right away. Deletions @@ -476,6 +481,8 @@ int rhashtable_shrink(struct rhashtable *ht) if (new_tbl == NULL) return -ENOMEM; + new_tbl->hash_rnd = tbl->hash_rnd; + rcu_assign_pointer(ht->future_tbl, new_tbl); synchronize_rcu(); @@ -1099,14 +1106,13 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params) if (tbl == NULL) return -ENOMEM; + get_random_bytes(&tbl->hash_rnd, sizeof(tbl->hash_rnd)); + atomic_set(&ht->nelems, 0); atomic_set(&ht->shift, ilog2(tbl->size)); RCU_INIT_POINTER(ht->tbl, tbl); RCU_INIT_POINTER(ht->future_tbl, tbl); - if (!ht->p.hash_rnd) - get_random_bytes(&ht->p.hash_rnd, sizeof(ht->p.hash_rnd)); - INIT_WORK(&ht->run_work, rht_deferred_worker); return 0; -- cgit v1.2.3