Introduce io_queues_lock

The queues can be created and destroyed dynamically at any point in
the cache lifetime, and this can happen from different execution contexts,
thus there is a need to protect the queue_list with a lock.

Signed-off-by: Robert Baldyga <robert.baldyga@huawei.com>
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>

src/mngt/ocf_mngt_cache.c

@@ -850,6 +850,11 @@ static int _ocf_mngt_init_new_cache(struct ocf_cache_mngt_init_params *params)
 		goto lock_err;
 	}
 
+	INIT_LIST_HEAD(&cache->io_queues);
+	result = env_spinlock_init(&cache->io_queues_lock);
+	if (result)
+		goto mutex_err;
+
 	ENV_BUG_ON(!ocf_refcnt_inc(&cache->refcnt.cache));
 
 	/* start with freezed metadata ref counter to indicate detached device*/
@@ -865,6 +870,8 @@ static int _ocf_mngt_init_new_cache(struct ocf_cache_mngt_init_params *params)
 
 	return 0;
 
+mutex_err:
+	env_mutex_destroy(&cache->flush_mutex);
 lock_err:
 	ocf_mngt_cache_unlock(cache);
 	ocf_mngt_cache_lock_deinit(cache);
@@ -1438,6 +1445,8 @@ static void _ocf_mngt_init_handle_error(ocf_ctx_t ctx,
 	if (!params->flags.cache_alloc)
 		return;
 
+	env_spinlock_destroy(&cache->io_queues_lock);
+
 	env_mutex_destroy(&cache->flush_mutex);
 
 	ocf_mngt_cache_lock_deinit(cache);
@@ -1466,8 +1475,6 @@ static void _ocf_mngt_cache_init(ocf_cache_t cache,
 	cache->conf_meta->promotion_policy_type = params->metadata.promotion_policy;
 	__set_cleaning_policy(cache, ocf_cleaning_default);
 
-	INIT_LIST_HEAD(&cache->io_queues);
-
 	/* Init Partitions */
 	ocf_user_part_init(cache);
 	__init_free(cache);
@@ -2197,6 +2204,9 @@ static void ocf_mngt_cache_remove(ocf_ctx_t ctx, ocf_cache_t cache)
 
 	/* Deinitialize locks */
 	ocf_mngt_cache_lock_deinit(cache);
+
+	env_spinlock_destroy(&cache->io_queues_lock);
+
 	env_mutex_destroy(&cache->flush_mutex);
 
 	/* Remove cache from the list */

src/ocf_cache_priv.h

@@ -107,6 +107,8 @@ struct ocf_cache {
 	struct ocf_cleaner cleaner;
 
 	struct list_head io_queues;
+	env_spinlock io_queues_lock;
+
 	ocf_promotion_policy_t promotion_policy;
 
 	struct {

src/ocf_queue.c

@@ -48,6 +48,7 @@ int ocf_queue_create(ocf_cache_t cache, ocf_queue_t *queue,
 {
 	ocf_queue_t tmp_queue;
 	int result;
+	unsigned long flags = 0;
 
 	OCF_CHECK_NULL(cache);
 
@@ -68,7 +69,9 @@ int ocf_queue_create(ocf_cache_t cache, ocf_queue_t *queue,
 		return result;
 	}
 
+	env_spinlock_lock_irqsave(&cache->io_queues_lock, flags);
 	list_add(&tmp_queue->list, &cache->io_queues);
+	env_spinlock_unlock_irqrestore(&cache->io_queues_lock, flags);
 
 	*queue = tmp_queue;
 
@@ -112,19 +115,25 @@ void ocf_queue_get(ocf_queue_t queue)
 
 void ocf_queue_put(ocf_queue_t queue)
 {
+	ocf_cache_t cache = queue->cache;
+	unsigned long flags = 0;
+
 	OCF_CHECK_NULL(queue);
 
-	if (env_atomic_dec_return(&queue->ref_count) == 0) {
+	if (env_atomic_dec_return(&queue->ref_count))
+		return;
+
 	queue->ops->stop(queue);
 	if (queue != queue->cache->mngt_queue) {
+		env_spinlock_lock_irqsave(&cache->io_queues_lock, flags);
 		list_del(&queue->list);
+		env_spinlock_unlock_irqrestore(&cache->io_queues_lock, flags);
 		ocf_queue_seq_cutoff_deinit(queue);
 	}
 	ocf_mngt_cache_put(queue->cache);
 	env_spinlock_destroy(&queue->io_list_lock);
 	env_free(queue);
 }
-}
 
 void ocf_io_handle(struct ocf_io *io, void *opaque)
 {