kernel-aes67/drivers/md/dm-vdo/action-manager.h

111 lines
4.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright 2023 Red Hat
*/
#ifndef VDO_ACTION_MANAGER_H
#define VDO_ACTION_MANAGER_H
#include "admin-state.h"
#include "types.h"
/*
* An action_manager provides a generic mechanism for applying actions to multi-zone entities (such
* as the block map or slab depot). Each action manager is tied to a specific context for which it
* manages actions. The manager ensures that only one action is active on that context at a time,
* and supports at most one pending action. Calls to schedule an action when there is already a
* pending action will result in VDO_COMPONENT_BUSY errors. Actions may only be submitted to the
* action manager from a single thread (which thread is determined when the action manager is
* constructed).
*
* A scheduled action consists of four components:
*
* preamble
* an optional method to be run on the initiator thread before applying the action to all zones
* zone_action
* an optional method to be applied to each of the zones
* conclusion
* an optional method to be run on the initiator thread once the per-zone method has been
* applied to all zones
* parent
* an optional completion to be finished once the conclusion is done
*
* At least one of the three methods must be provided.
*/
/*
* A function which is to be applied asynchronously to a set of zones.
* @context: The object which holds the per-zone context for the action
* @zone_number: The number of zone to which the action is being applied
* @parent: The object to notify when the action is complete
*/
typedef void (*vdo_zone_action_fn)(void *context, zone_count_t zone_number,
struct vdo_completion *parent);
/*
* A function which is to be applied asynchronously on an action manager's initiator thread as the
* preamble of an action.
* @context: The object which holds the per-zone context for the action
* @parent: The object to notify when the action is complete
*/
typedef void (*vdo_action_preamble_fn)(void *context, struct vdo_completion *parent);
/*
* A function which will run on the action manager's initiator thread as the conclusion of an
* action.
* @context: The object which holds the per-zone context for the action
*
* Return: VDO_SUCCESS or an error
*/
typedef int (*vdo_action_conclusion_fn)(void *context);
/*
* A function to schedule an action.
* @context: The object which holds the per-zone context for the action
*
* Return: true if an action was scheduled
*/
typedef bool (*vdo_action_scheduler_fn)(void *context);
/*
* A function to get the id of the thread associated with a given zone.
* @context: The action context
* @zone_number: The number of the zone for which the thread ID is desired
*/
typedef thread_id_t (*vdo_zone_thread_getter_fn)(void *context, zone_count_t zone_number);
struct action_manager;
int __must_check vdo_make_action_manager(zone_count_t zones,
vdo_zone_thread_getter_fn get_zone_thread_id,
thread_id_t initiator_thread_id, void *context,
vdo_action_scheduler_fn scheduler,
struct vdo *vdo,
struct action_manager **manager_ptr);
const struct admin_state_code *__must_check
vdo_get_current_manager_operation(struct action_manager *manager);
void * __must_check vdo_get_current_action_context(struct action_manager *manager);
bool vdo_schedule_default_action(struct action_manager *manager);
bool vdo_schedule_action(struct action_manager *manager, vdo_action_preamble_fn preamble,
vdo_zone_action_fn action, vdo_action_conclusion_fn conclusion,
struct vdo_completion *parent);
bool vdo_schedule_operation(struct action_manager *manager,
const struct admin_state_code *operation,
vdo_action_preamble_fn preamble, vdo_zone_action_fn action,
vdo_action_conclusion_fn conclusion,
struct vdo_completion *parent);
bool vdo_schedule_operation_with_context(struct action_manager *manager,
const struct admin_state_code *operation,
vdo_action_preamble_fn preamble,
vdo_zone_action_fn action,
vdo_action_conclusion_fn conclusion,
void *context, struct vdo_completion *parent);
#endif /* VDO_ACTION_MANAGER_H */