From 5e2847432223b6dc5bdb25a1f18a5217afdd8127 Mon Sep 17 00:00:00 2001
From: Adam Rutkowski <adam.j.rutkowski@intel.com>
Date: Mon, 23 Sep 2019 11:08:27 -0400
Subject: [PATCH] Adding partition locks

Adding locks to assure partition list consistency. Partition
lists is typically modified under cacheline or hash bucket lock.
This is not sufficient synchronization as adding/removing cacheline
from partition list affects neighbouring cachelines state as well.

Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
---
 src/concurrency/ocf_metadata_concurrency.c | 12 ++++++++++++
 src/concurrency/ocf_metadata_concurrency.h | 14 ++++++++++++++
 src/metadata/metadata_partition.c          |  8 ++++++++
 src/metadata/metadata_structs.h            |  1 +
 4 files changed, 35 insertions(+)

diff --git a/src/concurrency/ocf_metadata_concurrency.c b/src/concurrency/ocf_metadata_concurrency.c
index 058271b..59814b3 100644
--- a/src/concurrency/ocf_metadata_concurrency.c
+++ b/src/concurrency/ocf_metadata_concurrency.c
@@ -8,13 +8,25 @@
 
 void ocf_metadata_concurrency_init(struct ocf_metadata_lock *metadata_lock)
 {
+	unsigned i;
+
 	env_spinlock_init(&metadata_lock->eviction);
 	env_rwlock_init(&metadata_lock->status);
 	env_rwsem_init(&metadata_lock->global);
+
+	for (i = 0; i < OCF_IO_CLASS_MAX; i++) {
+		env_spinlock_init(&metadata_lock->partition[i]);
+	}
 }
 
 void ocf_metadata_concurrency_deinit(struct ocf_metadata_lock *metadata_lock)
 {
+	unsigned i;
+
+	for (i = 0; i < OCF_IO_CLASS_MAX; i++) {
+		env_spinlock_destroy(&metadata_lock->partition[i]);
+	}
+
 	env_spinlock_destroy(&metadata_lock->eviction);
 	env_rwlock_destroy(&metadata_lock->status);
 	env_rwsem_destroy(&metadata_lock->global);
diff --git a/src/concurrency/ocf_metadata_concurrency.h b/src/concurrency/ocf_metadata_concurrency.h
index ffef123..1445602 100644
--- a/src/concurrency/ocf_metadata_concurrency.h
+++ b/src/concurrency/ocf_metadata_concurrency.h
@@ -33,6 +33,20 @@ static inline void ocf_metadata_eviction_unlock(
 	env_spinlock_unlock(&metadata_lock->eviction);
 }
 
+static inline void ocf_metadata_partition_lock(
+		struct ocf_metadata_lock *metadata_lock,
+		ocf_part_id_t part_id)
+{
+	env_spinlock_lock(&metadata_lock->partition[part_id]);
+}
+
+static inline void ocf_metadata_partition_unlock(
+		struct ocf_metadata_lock *metadata_lock,
+		ocf_part_id_t part_id)
+{
+	env_spinlock_unlock(&metadata_lock->partition[part_id]);
+}
+
 #define OCF_METADATA_EVICTION_LOCK() \
 		ocf_metadata_eviction_lock(&cache->metadata.lock)
 
diff --git a/src/metadata/metadata_partition.c b/src/metadata/metadata_partition.c
index b802101..437f400 100644
--- a/src/metadata/metadata_partition.c
+++ b/src/metadata/metadata_partition.c
@@ -26,6 +26,8 @@ void ocf_metadata_add_to_partition(struct ocf_cache *cache,
 
 	ENV_BUG_ON(!(line < line_entries));
 
+	ocf_metadata_partition_lock(&cache->metadata.lock, part_id);
+
 	/* First node to be added/ */
 	if (!part->runtime->curr_size) {
 
@@ -55,6 +57,8 @@ void ocf_metadata_add_to_partition(struct ocf_cache *cache,
 	}
 
 	part->runtime->curr_size++;
+
+	ocf_metadata_partition_unlock(&cache->metadata.lock, part_id);
 }
 
 /* Deletes the node with the given collision_index from the Partition list */
@@ -68,6 +72,8 @@ void ocf_metadata_remove_from_partition(struct ocf_cache *cache,
 
 	ENV_BUG_ON(!(line < line_entries));
 
+	ocf_metadata_partition_lock(&cache->metadata.lock, part_id);
+
 	/* Get Partition info */
 	ocf_metadata_get_partition_info(cache, line, NULL,
 			&next_line, &prev_line);
@@ -131,4 +137,6 @@ void ocf_metadata_remove_from_partition(struct ocf_cache *cache,
 	}
 
 	part->runtime->curr_size--;
+
+	ocf_metadata_partition_unlock(&cache->metadata.lock, part_id);
 }
diff --git a/src/metadata/metadata_structs.h b/src/metadata/metadata_structs.h
index 9d6e681..71eb02a 100644
--- a/src/metadata/metadata_structs.h
+++ b/src/metadata/metadata_structs.h
@@ -441,6 +441,7 @@ struct ocf_metadata_lock
 	env_spinlock eviction; /*!< Fast lock for eviction policy */
 	env_rwsem *hash; /*!< Hash bucket locks */
 	env_rwsem *collision_pages; /*!< Collision table page locks */
+	env_spinlock partition[OCF_IO_CLASS_MAX]; /* partition lock */
 	uint32_t num_hash_entries;  /*!< Hash bucket count */
 	uint32_t num_collision_pages; /*!< Collision table page count */
 	ocf_cache_t cache;  /*!< Parent cache object */