Introduce composite detach

.checkpatch.conf

@@ -11,6 +11,7 @@
 --ignore NEW_TYPEDEFS
 --ignore PREFER_DEFINED_ATTRIBUTE_MACRO
 --ignore REPEATED_WORD
+--ignore MULTILINE_DEREFERENCE
 
 --exclude .github
 --exclude doc

example/simple/src/volume.c

@@ -1,6 +1,7 @@
 /*
  * Copyright(c) 2019-2022 Intel Corporation
  * Copyright(c) 2024 Huawei Technologies
+ * Copyright(c) 2026 Unvertical
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -103,6 +104,7 @@ const struct ocf_volume_properties volume_properties = {
 	.volume_priv_size = sizeof(struct myvolume),
 	.caps = {
 		.atomic_writes = 0,
+		.composite_volume = 0,
 	},
 	.ops = {
 		.open = volume_open,

inc/ocf_composite_volume.h

@@ -1,6 +1,7 @@
 /*
  * Copyright(c) 2022 Intel Corporation
  * Copyright(c) 2024 Huawei Technologies
+ * Copyright(c) 2026 Unvertical
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -41,33 +42,84 @@ int ocf_composite_volume_create(ocf_composite_volume_t *cvolume, ocf_ctx_t ctx);
  */
 void ocf_composite_volume_destroy(ocf_composite_volume_t cvolume);
 
+typedef enum {
+	ocf_composite_member_state_attached = 1,
+	/* If subvolume is opened it must be attached as well */
+	ocf_composite_member_state_opened = 3,
+	ocf_composite_member_state_detached = 4,
+	ocf_composite_member_state_any = 7,
+} ocf_composite_member_state_t;
+
 /**
- * @brief Add subvolume to composite volume
- *
- * @param[in] cvolume composite volume handle
- * @param[in] type type of added subvolume
- * @param[in] uuid UUID of added subvolume
- * @param[in] volume_params params to be passed to subvolume open
- *
- * @return Zero when success, othewise an error
+ * @param[in] subvolume Pointer to a subvolume
+ * @param[in] priv Priv
+ * @param[in] subvol_status flag with the info if current subvolume is opened,
+ *		attached or detached
  */
-int ocf_composite_volume_add(ocf_composite_volume_t cvolume,
-		ocf_volume_type_t type, struct ocf_volume_uuid *uuid,
-		void *volume_params);
-
 typedef int (*ocf_composite_volume_member_visitor_t)(ocf_volume_t subvolume,
-		void *priv);
+		void *priv, ocf_composite_member_state_t subvol_status);
 
 /**
  * @brief Call @visitor on every valid member of composite volume
  *
  * @param[in] cvolume composite volume handle
  * @param[in] visitor function callback
  * @param[in] priv pointer to be passed to the callback
+ * @param[in] subvol_status info whether iterate over
+ *		opened/attached/detached/all volumes
  *
- * @return subvolume in composite volume
+ * @return 0 if the visitor function was called for all subvolumes, error code
+ *		otherwise
  */
 int ocf_composite_volume_member_visit(ocf_composite_volume_t cvolume,
-		ocf_composite_volume_member_visitor_t visitor, void *priv);
+		ocf_composite_volume_member_visitor_t visitor, void *priv,
+		ocf_composite_member_state_t subvolume_status);
+
+/**
+ * @brief Get subvolume by index in composite volume
+ *
+ * @param[in] cvolume composite volume handle
+ * @param[in] index subvolume index
+ *
+ * @return subvolume in composite volume
+ */
+ocf_volume_t ocf_composite_volume_get_subvolume_by_index(
+		ocf_composite_volume_t cvolume, int index);
+
+/**
+ * @brief Get range of addresses from a subvolume
+ *
+ * @param[in] cvolume composite volume handle
+ * @param[in] subvolume_id subvolume index
+ * @param[out] begin_addr beginning of the address range
+ * @param[out] end_addr end of the address range
+ *
+ * @return 0 in case of success, error code otherwise
+ */
+int ocf_composite_volume_get_subvolume_addr_range(
+		ocf_composite_volume_t cvolume, uint8_t subvolume_id,
+		uint64_t *begin_addr, uint64_t *end_addr);
+
+/**
+ * @brief Set composite volume UUID
+ *
+ * @param[in] cvolume Volume
+ * @param[in] uuid UUID
+ *
+ * @return 0 in case of success, error code otherwise
+ */
+int ocf_composite_volume_set_uuid(ocf_composite_volume_t cvolume,
+		struct ocf_volume_uuid *uuid);
+
+/**
+ * @brief Get volume's id by UUID
+ *
+ * @param[in] volume Volume
+ * @param[in] uuid UUID
+ *
+ * @return id of the matching subvolume or error if the volume wasn't found
+ */
+int ocf_composite_volume_get_id_from_uuid(ocf_composite_volume_t cvolume,
+		ocf_uuid_t target_uuid);
 
 #endif /* __OCF_COMPOSITE_VOLUME_H__ */

inc/ocf_def.h

@@ -1,6 +1,7 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
  * Copyright(c) 2024 Huawei Technologies
+ * Copyright(c) 2026 Unvertical
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -93,6 +94,22 @@
  * @}
  */
 
+/**
+ * @name Composite volume defines
+ * @{
+ */
+/*
+ * Maximum value of a composite volume member id
+ */
+#define OCF_COMPOSITE_VOLUME_MEMBERS_MAX 16
+/*
+ * Invalid value of composite volume member
+ */
+#define OCF_COMPOSITE_VOLUME_MEMBER_ID_INVALID OCF_COMPOSITE_VOLUME_MEMBERS_MAX
+/**
+ * @}
+ */
+
 /**
  * @name Miscellaneous defines
  * @{

inc/ocf_err.h

@@ -1,6 +1,7 @@
 /*
  * Copyright(c) 2012-2021 Intel Corporation
  * Copyright(c) 2024 Huawei Technologies
+ * Copyright(c) 2026 Unvertical
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -72,6 +73,27 @@ typedef enum {
 	/** Core ID/name does not exist */
 	OCF_ERR_CORE_NOT_EXIST,
 
+	/** Composite volume member ID does not exist */
+	OCF_ERR_COMPOSITE_VOLUME_MEMBER_NOT_EXIST,
+
+	/** The volume is not a composite */
+	OCF_ERR_NOT_COMPOSITE_VOLUME,
+
+	/** Invalid subvolume ID */
+	OCF_ERR_COMPOSITE_INVALID_ID,
+
+	/** The target subvolume isn't initialised */
+	OCF_ERR_COMPOSITE_UNINITIALISED_VOLUME,
+
+	/** The target subvolume is already attached */
+	OCF_ERR_COMPOSITE_ATTACHED,
+
+	/** The target subvolume is already detached */
+	OCF_ERR_COMPOSITE_DETACHED,
+
+	/** The target subvolume has invalid size */
+	OCF_ERR_COMPOSITE_INVALID_SIZE,
+
 	/** Cache ID/name already exists */
 	OCF_ERR_CACHE_EXIST,
 

inc/ocf_mngt.h

@@ -1,6 +1,7 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
  * Copyright(c) 2024-2025 Huawei Technologies
+ * Copyright(c) 2026 Unvertical
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -513,6 +514,34 @@ typedef void (*ocf_mngt_cache_detach_end_t)(ocf_cache_t cache,
 void ocf_mngt_cache_detach(ocf_cache_t cache,
 		ocf_mngt_cache_detach_end_t cmpl, void *priv);
 
+/**
+ * @brief Add a new member to composite cache
+ *
+ * @param[in] cache Cache handle
+ * @param[in] vol_uuid UUID of the new volume to be added as a member
+ *				of composite
+ * @param[in] tgt_id Target subvolume id
+ * @param[in] vol_type Type of the new volume
+ * @param[in] vol_params Params of the new volume
+ * @param[in] cmpl Completion callback
+ * @param[in] priv Completion callback context
+ */
+void ocf_mngt_cache_attach_composite(ocf_cache_t cache, ocf_uuid_t vol_uuid,
+		uint8_t tgt_id, ocf_volume_type_t vol_type, void *vol_params,
+		ocf_mngt_cache_detach_end_t cmpl, void *priv);
+
+/**
+ * @brief Detach a member of composite cache
+ *
+ * @param[in] cache Cache handle
+ * @param[in] cmpl Completion callback
+ * @param[in] target_uuid uuid of the target subvolume
+ * @param[in] priv Completion callback context
+ */
+void ocf_mngt_cache_detach_composite(ocf_cache_t cache,
+		ocf_mngt_cache_detach_end_t cmpl, ocf_uuid_t target_uuid,
+		void *priv);
+
 /**
  * @brief Completion callback of cache load operation
  *

inc/ocf_volume.h

@@ -40,6 +40,9 @@ struct ocf_volume_uuid {
 struct ocf_volume_caps {
 	uint32_t atomic_writes : 1;
 		/*!< Volume supports atomic writes */
+
+	uint32_t composite_volume : 1;
+		/*!< Volume may be composed of multiple sub-volumes */
 };
 
 /**
@@ -211,6 +214,46 @@ struct ocf_volume_ops {
 	 * @return Maximum io size in bytes
 	 */
 	unsigned int (*get_max_io_size)(ocf_volume_t volume);
+
+	/**
+	 * @brief Add subvolume to composite volume
+	 *
+	 * @param[in] volume composite volume handle
+	 * @param[in] type type of added subvolume
+	 * @param[in] uuid UUID of added subvolume
+	 * @param[in] volume_params params to be passed to subvolume open
+	 *
+	 * @return Zero when success, otherwise an error
+	 */
+	int (*composite_volume_add)(ocf_volume_t cvolume,
+			ocf_volume_type_t type, struct ocf_volume_uuid *uuid,
+			void *volume_params);
+
+	/**
+	 * @brief Attach subvolume to composite volume
+	 *
+	 * @param[in] volume composite volume handle
+	 * @param[in] uuid UUID of added subvolume
+	 * @param[in] tgt_id Target subvolume id
+	 * @param[in] type type of added subvolume
+	 * @param[in] volume_params params to be passed to subvolume open
+	 *
+	 * @return Zero when success, otherwise an error
+	 */
+	int (*composite_volume_attach_member)(ocf_volume_t volume,
+			struct ocf_volume_uuid *uuid, uint8_t tgt_id,
+			ocf_volume_type_t type, void *volume_params);
+
+	/**
+	 * @brief Detach composite member volume
+	 *
+	 * @param[in] volume composite volume handle
+	 * @param[in] subvolume_id volume to be detached
+	 *
+	 * @return Zero on success, otherwise error code
+	 */
+	int (*composite_volume_detach_member)(ocf_volume_t volume,
+			uint8_t subvolume_id);
 };
 
 /**
@@ -337,6 +380,15 @@ ocf_cache_t ocf_volume_get_cache(ocf_volume_t volume);
  */
 int ocf_volume_is_atomic(ocf_volume_t volume);
 
+/**
+ * @brief Check if volume is composited of multiple sub-volumes
+ *
+ * @param[in] volume Volume
+ *
+ * @return True if volume is composite, otherwise false
+ */
+bool ocf_volume_is_composite(ocf_volume_t volume);
+
 /**
  * @brief Allocate new io
  *
@@ -387,12 +439,37 @@ void ocf_volume_submit_discard(ocf_io_t io);
 int ocf_volume_open(ocf_volume_t volume, void *volume_params);
 
 /**
- * @brief Get volume max io size
+ * @brief Close volume
  *
  * @param[in] volume Volume
  */
 void ocf_volume_close(ocf_volume_t volume);
 
+/**
+ * @brief Attach subvolume to composite volume
+ *
+ * @param[in] volume composite volume handle
+ * @param[in] tgt_id Target subvolume id
+ * @param[in] uuid UUID of added subvolume
+ * @param[in] type type of added subvolume
+ * @param[in] volume_params params to be passed to subvolume open
+ *
+ * @return Zero when success, otherwise an error
+ */
+int ocf_composite_volume_attach_member(ocf_volume_t volume, ocf_uuid_t uuid,
+		uint8_t tgt_id, ocf_volume_type_t vol_type, void *vol_params);
+
+/**
+ * @brief Detach composite member volume
+ *
+ * @param[in] volume composite volume handle
+ * @param[in] subvolume_id volume to be detached
+ *
+ * @return Zero when success, otherwise an error
+ */
+int ocf_composite_volume_detach_member(ocf_volume_t volume,
+		uint8_t subvolume_id);
+
 /**
  * @brief Get volume max io size
  *
@@ -402,6 +479,19 @@ void ocf_volume_close(ocf_volume_t volume);
  */
 unsigned int ocf_volume_get_max_io_size(ocf_volume_t volume);
 
+/**
+ * @brief Add subvolume to composite volume
+ *
+ * @param[in] volume composite volume handle
+ * @param[in] type type of added subvolume
+ * @param[in] uuid UUID of added subvolume
+ * @param[in] volume_params params to be passed to subvolume open
+ *
+ * @return Zero when success, otherwise an error
+ */
+int ocf_composite_volume_add(ocf_volume_t volume, ocf_volume_type_t type,
+		struct ocf_volume_uuid *uuid, void *volume_params);
+
 /**
  * @brief Get volume length
  *

src/metadata/metadata.c

@@ -605,6 +605,8 @@ static int ocf_metadata_init_fixed_size(struct ocf_cache *cache,
 			&part_runtime_meta[i].runtime;
 	}
 	cache->free.runtime= &part_runtime_meta[PARTITION_FREELIST].runtime;
+	cache->free_detached.runtime =
+		&part_runtime_meta[PARTITION_FREE_DETACHED].runtime;
 
 	/* Set core metadata */
 	core_meta_config = METADATA_MEM_POOL(ctrl,