diff options
| -rw-r--r-- | include/linux/rhashtable.h | 5 | ||||
| -rw-r--r-- | lib/rhashtable.c | 49 | ||||
| -rw-r--r-- | net/netfilter/nft_hash.c | 25 |
3 files changed, 49 insertions, 30 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index ae26c49..99f2e49 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -136,12 +136,10 @@ struct rhashtable_params { * @run_work: Deferred worker to expand/shrink asynchronously * @mutex: Mutex to protect current/future table swapping * @lock: Spin lock to protect walker list - * @being_destroyed: True if table is set up for destruction */ struct rhashtable { struct bucket_table __rcu *tbl; atomic_t nelems; - bool being_destroyed; unsigned int key_len; unsigned int elasticity; struct rhashtable_params p; @@ -334,6 +332,9 @@ int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU); void *rhashtable_walk_next(struct rhashtable_iter *iter); void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU); +void rhashtable_free_and_destroy(struct rhashtable *ht, + void (*free_fn)(void *ptr, void *arg), + void *arg); void rhashtable_destroy(struct rhashtable *ht); #define rht_dereference(p, ht) \ diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 50374d1..4b7b7e6 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -359,8 +359,6 @@ static void rht_deferred_worker(struct work_struct *work) ht = container_of(work, struct rhashtable, run_work); mutex_lock(&ht->mutex); - if (ht->being_destroyed) - goto unlock; tbl = rht_dereference(ht->tbl, ht); tbl = rhashtable_last_table(ht, tbl); @@ -372,7 +370,6 @@ static void rht_deferred_worker(struct work_struct *work) err = rhashtable_rehash_table(ht); -unlock: mutex_unlock(&ht->mutex); if (err) @@ -783,21 +780,53 @@ int rhashtable_init(struct rhashtable *ht, EXPORT_SYMBOL_GPL(rhashtable_init); /** - * rhashtable_destroy - destroy hash table + * rhashtable_free_and_destroy - free elements and destroy hash table * @ht: the hash table to destroy + * @free_fn: callback to release resources of element + * @arg: pointer passed to free_fn * - * 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. + * Stops an eventual async resize. If defined, invokes free_fn for each + * element to releasal resources. Please note that RCU protected + * readers may still be accessing the elements. Releasing of resources + * must occur in a compatible manner. Then frees the bucket array. + * + * This function will eventually sleep to wait for an async resize + * to complete. The caller is responsible that no further write operations + * occurs in parallel. */ -void rhashtable_destroy(struct rhashtable *ht) +void rhashtable_free_and_destroy(struct rhashtable *ht, + void (*free_fn)(void *ptr, void *arg), + void *arg) { - ht->being_destroyed = true; + const struct bucket_table *tbl; + unsigned int i; cancel_work_sync(&ht->run_work); mutex_lock(&ht->mutex); - bucket_table_free(rht_dereference(ht->tbl, ht)); + tbl = rht_dereference(ht->tbl, ht); + if (free_fn) { + for (i = 0; i < tbl->size; i++) { + struct rhash_head *pos, *next; + + for (pos = rht_dereference(tbl->buckets[i], ht), + next = !rht_is_a_nulls(pos) ? + rht_dereference(pos->next, ht) : NULL; + !rht_is_a_nulls(pos); + pos = next, + next = !rht_is_a_nulls(pos) ? + rht_dereference(pos->next, ht) : NULL) + free_fn(rht_obj(ht, pos), arg); + } + } + + bucket_table_free(tbl); mutex_unlock(&ht->mutex); } +EXPORT_SYMBOL_GPL(rhashtable_free_and_destroy); + +void rhashtable_destroy(struct rhashtable *ht) +{ + return rhashtable_free_and_destroy(ht, NULL, NULL); +} EXPORT_SYMBOL_GPL(rhashtable_destroy); diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c index 8577a37..f9ce219 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -188,26 +188,15 @@ static int nft_hash_init(const struct nft_set *set, return rhashtable_init(priv, ¶ms); } -static void nft_hash_destroy(const struct nft_set *set) +static void nft_free_element(void *ptr, void *arg) { - struct rhashtable *priv = nft_set_priv(set); - const struct bucket_table *tbl; - struct nft_hash_elem *he; - struct rhash_head *pos, *next; - unsigned int i; - - /* Stop an eventual async resizing */ - priv->being_destroyed = true; - mutex_lock(&priv->mutex); - - tbl = rht_dereference(priv->tbl, priv); - for (i = 0; i < tbl->size; i++) { - rht_for_each_entry_safe(he, pos, next, tbl, i, node) - nft_hash_elem_destroy(set, he); - } - mutex_unlock(&priv->mutex); + nft_hash_elem_destroy((const struct nft_set *)arg, ptr); +} - rhashtable_destroy(priv); +static void nft_hash_destroy(const struct nft_set *set) +{ + rhashtable_free_and_destroy(nft_set_priv(set), nft_free_element, + (void *)set); } static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features, |
