xref: /src/sys/dev/dm/dm.h

/*        $NetBSD: dm.h,v 1.23 2011/08/27 17:07:49 ahoka Exp $      */

/*
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Adam Hamsik.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _DM_DEV_H_
#define _DM_DEV_H_


#ifdef _KERNEL

#include <sys/errno.h>

#include <sys/atomic.h>
#include <sys/fcntl.h>
#include <sys/condvar.h>
#include <sys/kauth.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/queue.h>

#include <sys/device.h>
#include <sys/disk.h>
#include <sys/disklabel.h>

#include <prop/proplib.h>

#define DM_MAX_TYPE_NAME 16
#define DM_NAME_LEN 128
#define DM_UUID_LEN 129

#define DM_VERSION_MAJOR	4
#define DM_VERSION_MINOR	16

#define DM_VERSION_PATCHLEVEL	0

/*** Internal device-mapper structures ***/

/*
 * A table entry describes a physical range of the logical volume.
 */
#define MAX_TARGET_STRING_LEN 32

/*
 * A device mapper table is a list of physical ranges plus the mapping target
 * applied to them.
 */

typedef struct dm_table_entry {
	struct dm_dev *dm_dev;		/* backlink */
	uint64_t start;
	uint64_t length;

	struct dm_target *target;      /* Link to table target. */
	void *target_config;           /* Target specific data. */
	SLIST_ENTRY(dm_table_entry) next;
} dm_table_entry_t;

SLIST_HEAD(dm_table, dm_table_entry);

typedef struct dm_table dm_table_t;

typedef struct dm_table_head {
	/* Current active table is selected with this. */
	int cur_active_table;
	struct dm_table tables[2];

	kmutex_t   table_mtx;
	kcondvar_t table_cv; /*IO waiting cv */

	uint32_t io_cnt;
} dm_table_head_t;

#define MAX_DEV_NAME 32

/*
 * This structure is used to store opened vnodes for disk with name.
 * I need this because devices can be opened only once, but I can
 * have more then one device on one partition.
 */

typedef struct dm_pdev {
	char name[MAX_DEV_NAME];

	struct vnode *pdev_vnode;
	uint64_t pdev_numsec;
	unsigned pdev_secsize;
	int ref_cnt; /* reference counter for users ofthis pdev */

	SLIST_ENTRY(dm_pdev) next_pdev;
} dm_pdev_t;

/*
 * This structure is called for every device-mapper device.
 * It points to SLIST of device tables and mirrored, snapshoted etc. devices.
 */
TAILQ_HEAD(dm_dev_head, dm_dev) dm_devs;

typedef struct dm_dev {
	char name[DM_NAME_LEN];
	char uuid[DM_UUID_LEN];

	device_t devt; /* pointer to autoconf device_t structure */
	uint64_t minor; /* Device minor number */
	uint32_t flags; /* store communication protocol flags */

	kmutex_t dev_mtx; /* mutex for generall device lock */
	kcondvar_t dev_cv; /* cv for between ioctl synchronisation */

	uint32_t event_nr;
	uint32_t ref_cnt;

	uint32_t dev_type;

	dm_table_head_t table_head;

	struct dm_dev_head upcalls;

	struct disk *diskp;
	kmutex_t diskp_mtx;

	TAILQ_ENTRY(dm_dev) next_upcall; /* LIST of mirrored, snapshoted devices. */

	TAILQ_ENTRY(dm_dev) next_devlist; /* Major device list. */
} dm_dev_t;

/* Device types used for upcalls */
#define DM_ZERO_DEV            (1 << 0)
#define DM_ERROR_DEV           (1 << 1)
#define DM_LINEAR_DEV          (1 << 2)
#define DM_MIRROR_DEV          (1 << 3)
#define DM_STRIPE_DEV          (1 << 4)
#define DM_SNAPSHOT_DEV        (1 << 5)
#define DM_SNAPSHOT_ORIG_DEV   (1 << 6)
#define DM_SPARE_DEV           (1 << 7)
/* Set this device type only during dev remove ioctl. */
#define DM_DELETING_DEV        (1 << 8)


/* for zero, error : dm_target->target_config == NULL */

/*
 * Target config is initiated with target_init function.
 */

/* for linear : */
typedef struct target_linear_config {
	dm_pdev_t *pdev;
	uint64_t offset;
	TAILQ_ENTRY(target_linear_config) entries;
} dm_target_linear_config_t;

/*
 * Striping devices are stored in a linked list, this might be inefficient
 * for more than 8 striping devices and can be changed to something more
 * scalable.
 * TODO: look for other options than linked list.
 */
TAILQ_HEAD(target_linear_devs, target_linear_config);

typedef struct target_linear_devs dm_target_linear_devs_t;

/* for stripe : */
typedef struct target_stripe_config {
#define DM_STRIPE_DEV_OFFSET 2
	struct target_linear_devs stripe_devs;
	uint8_t stripe_num;
	uint64_t stripe_chunksize;
	size_t params_len;
} dm_target_stripe_config_t;

/* for mirror : */
typedef struct target_mirror_config {
#define MAX_MIRROR_COPIES 4
	dm_pdev_t *orig;
	dm_pdev_t *copies[MAX_MIRROR_COPIES];

	/* copied blocks bitmaps administration etc*/
	dm_pdev_t *log_pdev;	/* for administration */
	uint64_t log_regionsize;	/* blocksize of mirror */

	/* list of parts that still need copied etc.; run length encoded? */
} dm_target_mirror_config_t;


/* for snapshot : */
typedef struct target_snapshot_config {
	dm_pdev_t *tsc_snap_dev;
	/* cow dev is set only for persistent snapshot devices */
	dm_pdev_t *tsc_cow_dev;

	uint64_t tsc_chunk_size;
	uint32_t tsc_persistent_dev;
} dm_target_snapshot_config_t;

/* for snapshot-origin devices */
typedef struct target_snapshot_origin_config {
	dm_pdev_t *tsoc_real_dev;
	/* list of snapshots ? */
} dm_target_snapshot_origin_config_t;

/* constant dm_target structures for error, zero, linear, stripes etc. */
typedef struct dm_target {
	char name[DM_MAX_TYPE_NAME];
	/* Initialize target_config area */
	int (*init)(dm_dev_t *, void **, char *);

	/* Destroy target_config area */
	int (*destroy)(dm_table_entry_t *);

	int (*deps) (dm_table_entry_t *, prop_array_t);
	/*
	 * Status routine is called to get params string, which is target
	 * specific. When dm_table_status_ioctl is called with flag
	 * DM_STATUS_TABLE_FLAG I have to sent params string back.
	 */
	char * (*status)(void *);
	int (*strategy)(dm_table_entry_t *, struct buf *);
	int (*sync)(dm_table_entry_t *);
	int (*upcall)(dm_table_entry_t *, struct buf *);
	int (*secsize)(dm_table_entry_t *, unsigned *);

	uint32_t version[3];
	int ref_cnt;

	TAILQ_ENTRY(dm_target) dm_target_next;
} dm_target_t;

/* Interface structures */

/*
 * This structure is used to translate command sent to kernel driver in
 * <key>command</key>
 * <value></value>
 * to function which I can call, and if the command is allowed for
 * non-superusers.
 */
struct cmd_function {
	const char *cmd;
	int  (*fn)(prop_dictionary_t);
	int  allowed;
};

/* device-mapper */
void dmgetproperties(struct disk *, dm_table_head_t *);

/* dm_ioctl.c */
int dm_dev_create_ioctl(prop_dictionary_t);
int dm_dev_list_ioctl(prop_dictionary_t);
int dm_dev_remove_ioctl(prop_dictionary_t);
int dm_dev_rename_ioctl(prop_dictionary_t);
int dm_dev_resume_ioctl(prop_dictionary_t);
int dm_dev_status_ioctl(prop_dictionary_t);
int dm_dev_suspend_ioctl(prop_dictionary_t);

int dm_check_version(prop_dictionary_t);
int dm_get_version_ioctl(prop_dictionary_t);
int dm_list_versions_ioctl(prop_dictionary_t);

int dm_table_clear_ioctl(prop_dictionary_t);
int dm_table_deps_ioctl(prop_dictionary_t);
int dm_table_load_ioctl(prop_dictionary_t);
int dm_table_status_ioctl(prop_dictionary_t);

/* dm_target.c */
dm_target_t* dm_target_alloc(const char *);
dm_target_t* dm_target_autoload(const char *);
int dm_target_destroy(void);
int dm_target_insert(dm_target_t *);
prop_array_t dm_target_prop_list(void);
dm_target_t* dm_target_lookup(const char *);
int dm_target_rem(char *);
void dm_target_unbusy(dm_target_t *);
void dm_target_busy(dm_target_t *);

/* XXX temporally add */
int dm_target_init(void);

#define DM_MAX_PARAMS_SIZE 1024

/* dm_target_linear.c */
int dm_target_linear_init(dm_dev_t *, void**, char *);
char * dm_target_linear_status(void *);
int dm_target_linear_strategy(dm_table_entry_t *, struct buf *);
int dm_target_linear_sync(dm_table_entry_t *);
int dm_target_linear_deps(dm_table_entry_t *, prop_array_t);
int dm_target_linear_destroy(dm_table_entry_t *);
int dm_target_linear_upcall(dm_table_entry_t *, struct buf *);
int dm_target_linear_secsize(dm_table_entry_t *, unsigned *);

/* Generic function used to convert char to string */
uint64_t atoi(const char *);

/* dm_target_stripe.c */
int dm_target_stripe_init(dm_dev_t *, void**, char *);
char * dm_target_stripe_status(void *);
int dm_target_stripe_strategy(dm_table_entry_t *, struct buf *);
int dm_target_stripe_sync(dm_table_entry_t *);
int dm_target_stripe_deps(dm_table_entry_t *, prop_array_t);
int dm_target_stripe_destroy(dm_table_entry_t *);
int dm_target_stripe_upcall(dm_table_entry_t *, struct buf *);
int dm_target_stripe_secsize(dm_table_entry_t *, unsigned *);

/* dm_table.c  */
#define DM_TABLE_ACTIVE 0
#define DM_TABLE_INACTIVE 1

int dm_table_destroy(dm_table_head_t *, uint8_t);
uint64_t dm_table_size(dm_table_head_t *);
uint64_t dm_inactive_table_size(dm_table_head_t *);
void dm_table_disksize(dm_table_head_t *, uint64_t *, unsigned *);
dm_table_t * dm_table_get_entry(dm_table_head_t *, uint8_t);
int dm_table_get_target_count(dm_table_head_t *, uint8_t);
void dm_table_release(dm_table_head_t *, uint8_t s);
void dm_table_switch_tables(dm_table_head_t *);
void dm_table_head_init(dm_table_head_t *);
void dm_table_head_destroy(dm_table_head_t *);

/* dm_dev.c */
dm_dev_t* dm_dev_alloc(void);
void dm_dev_busy(dm_dev_t *);
int dm_dev_destroy(void);
dm_dev_t* dm_dev_detach(device_t);
int dm_dev_free(dm_dev_t *);
int dm_dev_init(void);
int dm_dev_insert(dm_dev_t *);
dm_dev_t* dm_dev_lookup(const char *, const char *, int);
prop_array_t dm_dev_prop_list(void);
dm_dev_t* dm_dev_rem(const char *, const char *, int);
/*int dm_dev_test_minor(int);*/
void dm_dev_unbusy(dm_dev_t *);

/* dm_pdev.c */
int dm_pdev_decr(dm_pdev_t *);
int dm_pdev_destroy(void);
int dm_pdev_init(void);
dm_pdev_t* dm_pdev_insert(const char *);

#endif /*_KERNEL*/

#endif /*_DM_DEV_H_*/