linux-stable/drivers/md/dm-rq.h

/*
 * Internal header file for device mapper
 *
 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef DM_RQ_INTERNAL_H
#define DM_RQ_INTERNAL_H

#include <linux/bio.h>
#include <linux/kthread.h>

#include "dm-stats.h"

struct mapped_device;

/*
 * One of these is allocated per request.
 */
struct dm_rq_target_io {
	struct mapped_device *md;
	struct dm_target *ti;
	struct request *orig, *clone;
	struct kthread_work work;
	int error;
	union map_info info;
	struct dm_stats_aux stats_aux;
	unsigned long duration_jiffies;
	unsigned n_sectors;
};

/*
 * For request-based dm - the bio clones we allocate are embedded in these
 * structs.
 *
 * We allocate these with bio_alloc_bioset, using the front_pad parameter when
 * the bioset is created - this means the bio has to come at the end of the
 * struct.
 */
struct dm_rq_clone_bio_info {
	struct bio *orig;
	struct dm_rq_target_io *tio;
	struct bio clone;
};

bool dm_use_blk_mq_default(void);
bool dm_use_blk_mq(struct mapped_device *md);

int dm_old_init_request_queue(struct mapped_device *md);
int dm_mq_init_request_queue(struct mapped_device *md, struct dm_table *t);
void dm_mq_cleanup_mapped_device(struct mapped_device *md);

void dm_start_queue(struct request_queue *q);
void dm_stop_queue(struct request_queue *q);

unsigned dm_get_reserved_rq_based_ios(void);

ssize_t dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device *md, char *buf);
ssize_t dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device *md,
						     const char *buf, size_t count);

#endif