linux/drivers/block/null_blk.h
Matias Bjørling ca4b2a0119 null_blk: add zone support
Adds support for exposing a null_blk device through the zone device
interface.

The interface is managed with the parameters zoned and zone_size.
If zoned is set, the null_blk instance registers as a zoned block
device. The zone_size parameter defines how big each zone will be.

Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09 09:07:55 -06:00

109 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BLK_NULL_BLK_H
#define __BLK_NULL_BLK_H
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/blk-mq.h>
#include <linux/hrtimer.h>
#include <linux/configfs.h>
#include <linux/badblocks.h>
#include <linux/fault-inject.h>
struct nullb_cmd {
struct list_head list;
struct llist_node ll_list;
struct __call_single_data csd;
struct request *rq;
struct bio *bio;
unsigned int tag;
blk_status_t error;
struct nullb_queue *nq;
struct hrtimer timer;
};
struct nullb_queue {
unsigned long *tag_map;
wait_queue_head_t wait;
unsigned int queue_depth;
struct nullb_device *dev;
unsigned int requeue_selection;
struct nullb_cmd *cmds;
};
struct nullb_device {
struct nullb *nullb;
struct config_item item;
struct radix_tree_root data; /* data stored in the disk */
struct radix_tree_root cache; /* disk cache data */
unsigned long flags; /* device flags */
unsigned int curr_cache;
struct badblocks badblocks;
unsigned int nr_zones;
struct blk_zone *zones;
sector_t zone_size_sects;
unsigned long size; /* device size in MB */
unsigned long completion_nsec; /* time in ns to complete a request */
unsigned long cache_size; /* disk cache size in MB */
unsigned long zone_size; /* zone size in MB if device is zoned */
unsigned int submit_queues; /* number of submission queues */
unsigned int home_node; /* home node for the device */
unsigned int queue_mode; /* block interface */
unsigned int blocksize; /* block size */
unsigned int irqmode; /* IRQ completion handler */
unsigned int hw_queue_depth; /* queue depth */
unsigned int index; /* index of the disk, only valid with a disk */
unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
bool blocking; /* blocking blk-mq device */
bool use_per_node_hctx; /* use per-node allocation for hardware context */
bool power; /* power on/off the device */
bool memory_backed; /* if data is stored in memory */
bool discard; /* if support discard */
bool zoned; /* if device is zoned */
};
struct nullb {
struct nullb_device *dev;
struct list_head list;
unsigned int index;
struct request_queue *q;
struct gendisk *disk;
struct blk_mq_tag_set *tag_set;
struct blk_mq_tag_set __tag_set;
unsigned int queue_depth;
atomic_long_t cur_bytes;
struct hrtimer bw_timer;
unsigned long cache_flush_pos;
spinlock_t lock;
struct nullb_queue *queues;
unsigned int nr_queues;
char disk_name[DISK_NAME_LEN];
};
#ifdef CONFIG_BLK_DEV_ZONED
int null_zone_init(struct nullb_device *dev);
void null_zone_exit(struct nullb_device *dev);
blk_status_t null_zone_report(struct nullb *nullb,
struct nullb_cmd *cmd);
void null_zone_write(struct nullb_cmd *cmd);
void null_zone_reset(struct nullb_cmd *cmd);
#else
static inline int null_zone_init(struct nullb_device *dev)
{
return -EINVAL;
}
static inline void null_zone_exit(struct nullb_device *dev) {}
static inline blk_status_t null_zone_report(struct nullb *nullb,
struct nullb_cmd *cmd)
{
return BLK_STS_NOTSUPP;
}
static inline void null_zone_write(struct nullb_cmd *cmd) {}
static inline void null_zone_reset(struct nullb_cmd *cmd) {}
#endif /* CONFIG_BLK_DEV_ZONED */
#endif /* __NULL_BLK_H */