[linux-2.6-block.git] / drivers / block / loop.h

/*
 * loop.h
 *
 * Written by Theodore Ts'o, 3/29/93.
 *
 * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
 * permitted under the GNU General Public License.
 */
#ifndef _LINUX_LOOP_H
#define _LINUX_LOOP_H

#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <uapi/linux/loop.h>

/* Possible states of device */
enum {
	Lo_unbound,
	Lo_bound,
	Lo_rundown,
};

struct loop_func_table;

struct loop_device {
	int		lo_number;
	atomic_t	lo_refcnt;
	loff_t		lo_offset;
	loff_t		lo_sizelimit;
	int		lo_flags;
	int		(*transfer)(struct loop_device *, int cmd,
				    struct page *raw_page, unsigned raw_off,
				    struct page *loop_page, unsigned loop_off,
				    int size, sector_t real_block);
	char		lo_file_name[LO_NAME_SIZE];
	char		lo_crypt_name[LO_NAME_SIZE];
	char		lo_encrypt_key[LO_KEY_SIZE];
	int		lo_encrypt_key_size;
	struct loop_func_table *lo_encryption;
	__u32           lo_init[2];
	kuid_t		lo_key_owner;	/* Who set the key */
	int		(*ioctl)(struct loop_device *, int cmd, 
				 unsigned long arg); 

	struct file *	lo_backing_file;
	struct block_device *lo_device;
	void		*key_data; 

	gfp_t		old_gfp_mask;

	spinlock_t		lo_lock;
	int			lo_state;
	struct kthread_worker	worker;
	struct task_struct	*worker_task;
	bool			use_dio;
	bool			sysfs_inited;

	struct request_queue	*lo_queue;
	struct blk_mq_tag_set	tag_set;
	struct gendisk		*lo_disk;
};

struct loop_cmd {
	struct kthread_work work;
	bool use_aio; /* use AIO interface to handle I/O */
	atomic_t ref; /* only for aio */
	long ret;
	struct kiocb iocb;
	struct bio_vec *bvec;
	struct cgroup_subsys_state *css;
};

/* Support for loadable transfer modules */
struct loop_func_table {
	int number;	/* filter type */ 
	int (*transfer)(struct loop_device *lo, int cmd,
			struct page *raw_page, unsigned raw_off,
			struct page *loop_page, unsigned loop_off,
			int size, sector_t real_block);
	int (*init)(struct loop_device *, const struct loop_info64 *); 
	/* release is called from loop_unregister_transfer or clr_fd */
	int (*release)(struct loop_device *); 
	int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
	struct module *owner;
}; 

int loop_register_transfer(struct loop_func_table *funcs);
int loop_unregister_transfer(int number); 

#endif
Commit	Line	Data
	1	/*
	2	* loop.h
	3	*
	4	* Written by Theodore Ts'o, 3/29/93.
	5	*
	6	* Copyright 1993 by Theodore Ts'o. Redistribution of this file is
	7	* permitted under the GNU General Public License.
	8	*/
	9	#ifndef _LINUX_LOOP_H
	10	#define _LINUX_LOOP_H
	11
	12	#include <linux/bio.h>
	13	#include <linux/blkdev.h>
	14	#include <linux/blk-mq.h>
	15	#include <linux/spinlock.h>
	16	#include <linux/mutex.h>
	17	#include <linux/kthread.h>
	18	#include <uapi/linux/loop.h>
	19
	20	/* Possible states of device */
	21	enum {
	22	Lo_unbound,
	23	Lo_bound,
	24	Lo_rundown,
	25	};
	26
	27	struct loop_func_table;
	28
	29	struct loop_device {
	30	int lo_number;
	31	atomic_t lo_refcnt;
	32	loff_t lo_offset;
	33	loff_t lo_sizelimit;
	34	int lo_flags;
	35	int (transfer)(struct loop_device , int cmd,
	36	struct page *raw_page, unsigned raw_off,
	37	struct page *loop_page, unsigned loop_off,
	38	int size, sector_t real_block);
	39	char lo_file_name[LO_NAME_SIZE];
	40	char lo_crypt_name[LO_NAME_SIZE];
	41	char lo_encrypt_key[LO_KEY_SIZE];
	42	int lo_encrypt_key_size;
	43	struct loop_func_table *lo_encryption;
	44	__u32 lo_init[2];
	45	kuid_t lo_key_owner; /* Who set the key */
	46	int (ioctl)(struct loop_device , int cmd,
	47	unsigned long arg);
	48
	49	struct file * lo_backing_file;
	50	struct block_device *lo_device;
	51	void *key_data;
	52
	53	gfp_t old_gfp_mask;
	54
	55	spinlock_t lo_lock;
	56	int lo_state;
	57	struct kthread_worker worker;
	58	struct task_struct *worker_task;
	59	bool use_dio;
	60	bool sysfs_inited;
	61
	62	struct request_queue *lo_queue;
	63	struct blk_mq_tag_set tag_set;
	64	struct gendisk *lo_disk;
	65	};
	66
	67	struct loop_cmd {
	68	struct kthread_work work;
	69	bool use_aio; /* use AIO interface to handle I/O */
	70	atomic_t ref; /* only for aio */
	71	long ret;
	72	struct kiocb iocb;
	73	struct bio_vec *bvec;
	74	struct cgroup_subsys_state *css;
	75	};
	76
	77	/* Support for loadable transfer modules */
	78	struct loop_func_table {
	79	int number; /* filter type */
	80	int (transfer)(struct loop_device lo, int cmd,
	81	struct page *raw_page, unsigned raw_off,
	82	struct page *loop_page, unsigned loop_off,
	83	int size, sector_t real_block);
	84	int (init)(struct loop_device , const struct loop_info64 *);
	85	/* release is called from loop_unregister_transfer or clr_fd */
	86	int (release)(struct loop_device );
	87	int (ioctl)(struct loop_device , int cmd, unsigned long arg);
	88	struct module *owner;
	89	};
	90
	91	int loop_register_transfer(struct loop_func_table *funcs);
	92	int loop_unregister_transfer(int number);
	93
	94	#endif