/*
 * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
 * Copyright (C) 2004-2014 Red Hat, Inc. All rights reserved.
 *
 * This file is part of the device-mapper userspace tools.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU Lesser General Public License v.2.1.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef LIB_DEVICE_MAPPER_H
#define LIB_DEVICE_MAPPER_H

#include <inttypes.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>

#ifdef __linux__
#  include <linux/types.h>
#endif

#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#ifndef __GNUC__
# define __typeof__ typeof
#endif

/* Macros to make string defines */
#define DM_TO_STRING_EXP(A) #A
#define DM_TO_STRING(A) DM_TO_STRING_EXP(A)

#define DM_ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))

#ifdef __cplusplus
extern "C" {
#endif

/*****************************************************************
 * The first section of this file provides direct access to the
 * individual device-mapper ioctls.  Since it is quite laborious to
 * build the ioctl arguments for the device-mapper, people are
 * encouraged to use this library.
 ****************************************************************/

/*
 * The library user may wish to register their own
 * logging function.  By default errors go to stderr.
 * Use dm_log_with_errno_init(NULL) to restore the default log fn.
 * Error messages may have a non-zero errno.
 * Debug messages may have a non-zero class.
 * Aborts on internal error when env DM_ABORT_ON_INTERNAL_ERRORS is 1
 */

typedef void (*dm_log_with_errno_fn) (int level, const char *file, int line,
				      int dm_errno_or_class, const char *f, ...)
    __attribute__ ((format(printf, 5, 6)));

void dm_log_with_errno_init(dm_log_with_errno_fn fn);
void dm_log_init_verbose(int level);

/*
 * Original version of this function.
 * dm_errno is set to 0.
 *
 * Deprecated: Use the _with_errno_ versions above instead.
 */
typedef void (*dm_log_fn) (int level, const char *file, int line,
			   const char *f, ...)
    __attribute__ ((format(printf, 4, 5)));

void dm_log_init(dm_log_fn fn);
/*
 * For backward-compatibility, indicate that dm_log_init() was used
 * to set a non-default value of dm_log().
 */
int dm_log_is_non_default(void);

/*
 * Number of devices currently in suspended state (via the library).
 */
int dm_get_suspended_counter(void);

enum {
	DM_DEVICE_CREATE,
	DM_DEVICE_RELOAD,
	DM_DEVICE_REMOVE,
	DM_DEVICE_REMOVE_ALL,

	DM_DEVICE_SUSPEND,
	DM_DEVICE_RESUME,

	DM_DEVICE_INFO,
	DM_DEVICE_DEPS,
	DM_DEVICE_RENAME,

	DM_DEVICE_VERSION,

	DM_DEVICE_STATUS,
	DM_DEVICE_TABLE,
	DM_DEVICE_WAITEVENT,

	DM_DEVICE_LIST,

	DM_DEVICE_CLEAR,

	DM_DEVICE_MKNODES,

	DM_DEVICE_LIST_VERSIONS,
	
	DM_DEVICE_TARGET_MSG,

	DM_DEVICE_SET_GEOMETRY
};

/*
 * You will need to build a struct dm_task for
 * each ioctl command you want to execute.
 */

struct dm_task;

struct dm_task *dm_task_create(int type);
void dm_task_destroy(struct dm_task *dmt);

int dm_task_set_name(struct dm_task *dmt, const char *name);
int dm_task_set_uuid(struct dm_task *dmt, const char *uuid);

/*
 * Retrieve attributes after an info.
 */
struct dm_info {
	int exists;
	int suspended;
	int live_table;
	int inactive_table;
	int32_t open_count;
	uint32_t event_nr;
	uint32_t major;
	uint32_t minor;		/* minor device number */
	int read_only;		/* 0:read-write; 1:read-only */

	int32_t target_count;
};

struct dm_deps {
	uint32_t count;
	uint32_t filler;
	uint64_t device[0];
};

struct dm_names {
	uint64_t dev;
	uint32_t next;		/* Offset to next struct from start of this struct */
	char name[0];
};

struct dm_versions {
	uint32_t next;		/* Offset to next struct from start of this struct */
	uint32_t version[3];

	char name[0];
};

int dm_get_library_version(char *version, size_t size);
int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size);
int dm_task_get_info(struct dm_task *dmt, struct dm_info *dmi);

/*
 * This function returns dm device's UUID based on the value
 * of the mangling mode set during preceding dm_task_run call:
 *   - unmangled UUID for DM_STRING_MANGLING_{AUTO, HEX},
 *   - UUID without any changes for DM_STRING_MANGLING_NONE.
 *
 * To get mangled or unmangled form of the UUID directly, use
 * dm_task_get_uuid_mangled or dm_task_get_uuid_unmangled function.
 */
const char *dm_task_get_uuid(const struct dm_task *dmt);

struct dm_deps *dm_task_get_deps(struct dm_task *dmt);
struct dm_versions *dm_task_get_versions(struct dm_task *dmt);
const char *dm_task_get_message_response(struct dm_task *dmt);

/*
 * These functions return device-mapper names based on the value
 * of the mangling mode set during preceding dm_task_run call:
 *   - unmangled name for DM_STRING_MANGLING_{AUTO, HEX},
 *   - name without any changes for DM_STRING_MANGLING_NONE.
 *
 * To get mangled or unmangled form of the name directly, use
 * dm_task_get_name_mangled or dm_task_get_name_unmangled function.
 */
const char *dm_task_get_name(const struct dm_task *dmt);
struct dm_names *dm_task_get_names(struct dm_task *dmt);

int dm_task_set_ro(struct dm_task *dmt);
int dm_task_set_newname(struct dm_task *dmt, const char *newname);
int dm_task_set_newuuid(struct dm_task *dmt, const char *newuuid);
int dm_task_set_minor(struct dm_task *dmt, int minor);
int dm_task_set_major(struct dm_task *dmt, int major);
int dm_task_set_major_minor(struct dm_task *dmt, int major, int minor, int allow_default_major_fallback);
int dm_task_set_uid(struct dm_task *dmt, uid_t uid);
int dm_task_set_gid(struct dm_task *dmt, gid_t gid);
int dm_task_set_mode(struct dm_task *dmt, mode_t mode);
int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags);
int dm_task_set_event_nr(struct dm_task *dmt, uint32_t event_nr);
int dm_task_set_geometry(struct dm_task *dmt, const char *cylinders, const char *heads, const char *sectors, const char *start);
int dm_task_set_message(struct dm_task *dmt, const char *message);
int dm_task_set_sector(struct dm_task *dmt, uint64_t sector);
int dm_task_no_flush(struct dm_task *dmt);
int dm_task_no_open_count(struct dm_task *dmt);
int dm_task_skip_lockfs(struct dm_task *dmt);
int dm_task_query_inactive_table(struct dm_task *dmt);
int dm_task_suppress_identical_reload(struct dm_task *dmt);
int dm_task_secure_data(struct dm_task *dmt);
int dm_task_retry_remove(struct dm_task *dmt);

/*
 * Enable checks for common mistakes such as issuing ioctls in an unsafe order.
 */
int dm_task_enable_checks(struct dm_task *dmt);

typedef enum {
	DM_ADD_NODE_ON_RESUME, /* add /dev/mapper node with dmsetup resume */
	DM_ADD_NODE_ON_CREATE  /* add /dev/mapper node with dmsetup create */
} dm_add_node_t;
int dm_task_set_add_node(struct dm_task *dmt, dm_add_node_t add_node);

/*
 * Control read_ahead.
 */
#define DM_READ_AHEAD_AUTO UINT32_MAX	/* Use kernel default readahead */
#define DM_READ_AHEAD_NONE 0		/* Disable readahead */

#define DM_READ_AHEAD_MINIMUM_FLAG	0x1	/* Value supplied is minimum */

/*
 * Read ahead is set with DM_DEVICE_CREATE with a table or DM_DEVICE_RESUME.
 */
int dm_task_set_read_ahead(struct dm_task *dmt, uint32_t read_ahead,
			   uint32_t read_ahead_flags);
uint32_t dm_task_get_read_ahead(const struct dm_task *dmt,
				uint32_t *read_ahead);

/*
 * Use these to prepare for a create or reload.
 */
int dm_task_add_target(struct dm_task *dmt,
		       uint64_t start,
		       uint64_t size, const char *ttype, const char *params);

/*
 * Format major/minor numbers correctly for input to driver.
 */
#define DM_FORMAT_DEV_BUFSIZE	13	/* Minimum bufsize to handle worst case. */
int dm_format_dev(char *buf, int bufsize, uint32_t dev_major, uint32_t dev_minor);

/* Use this to retrive target information returned from a STATUS call */
void *dm_get_next_target(struct dm_task *dmt,
			 void *next, uint64_t *start, uint64_t *length,
			 char **target_type, char **params);

/*
 * Parse params from STATUS call for raid target
 */
struct dm_pool;

/*
 * dm_get_status_raid will allocate the dm_status_raid structure and
 * the necessary character arrays from the mempool provided to the
 * function.  If the mempool is from a dev_manager struct (dm->mem),
 * then the caller does not need to free the memory - simply calling
 * dev_manager_destroy will do.
 */
struct dm_status_raid {
	uint64_t reserved;
	uint64_t total_regions;
	uint64_t insync_regions;
	uint64_t mismatch_count;
	uint32_t dev_count;
	char *raid_type;
	char *dev_health;
	char *sync_action;
};

int dm_get_status_raid(struct dm_pool *mem, const char *params,
		       struct dm_status_raid **status);

struct dm_status_cache {
	uint64_t version;  /* zero for now */

	uint32_t metadata_block_size;   /* in 512B sectors */
	uint32_t block_size;            /* AKA 'chunk_size' */

	uint64_t metadata_used_blocks;
	uint64_t metadata_total_blocks;

	uint64_t used_blocks;
	uint64_t dirty_blocks;
	uint64_t total_blocks;

	uint64_t read_hits;
	uint64_t read_misses;
	uint64_t write_hits;
	uint64_t write_misses;

	uint64_t demotions;
	uint64_t promotions;

	uint32_t feature_flags;

	int core_argc;
	char **core_argv;

	char *policy_name;
	int   policy_argc;
	char **policy_argv;
};

int dm_get_status_cache(struct dm_pool *mem, const char *params,
			struct dm_status_cache **status);

/*
 * Snapshot target's format:
 * <= 1.7.0: <used_sectors>/<total_sectors>
 * >= 1.8.0: <used_sectors>/<total_sectors> <metadata_sectors>
 */
struct dm_status_snapshot {
	uint64_t used_sectors;          /* in 512b units */
	uint64_t total_sectors;
	uint64_t metadata_sectors;
	unsigned has_metadata_sectors : 1; /* set when metadata_sectors is present */
	unsigned invalid : 1;		/* set when snapshot is invalidated */
	unsigned merge_failed : 1;	/* set when snapshot merge failed */
};

int dm_get_status_snapshot(struct dm_pool *mem, const char *params,
			   struct dm_status_snapshot **status);

/*
 * Parse params from STATUS call for thin_pool target
 */
typedef enum {
	DM_THIN_DISCARDS_IGNORE,
	DM_THIN_DISCARDS_NO_PASSDOWN,
	DM_THIN_DISCARDS_PASSDOWN
} dm_thin_discards_t;

struct dm_status_thin_pool {
	uint64_t transaction_id;
	uint64_t used_metadata_blocks;
	uint64_t total_metadata_blocks;
	uint64_t used_data_blocks;
	uint64_t total_data_blocks;
	uint64_t held_metadata_root;
	uint32_t read_only;
	dm_thin_discards_t discards;
};

int dm_get_status_thin_pool(struct dm_pool *mem, const char *params,
			    struct dm_status_thin_pool **status);

/*
 * Parse params from STATUS call for thin target
 */
struct dm_status_thin {
	uint64_t mapped_sectors;
	uint64_t highest_mapped_sector;
};

int dm_get_status_thin(struct dm_pool *mem, const char *params,
		       struct dm_status_thin **status);

/*
 * Call this to actually run the ioctl.
 */
int dm_task_run(struct dm_task *dmt);

/*
 * Call this to make or remove the device nodes associated with previously
 * issued commands.
 */
void dm_task_update_nodes(void);

/*
 * Mangling support
 *
 * Character whitelist: 0-9, A-Z, a-z, #+-.:=@_
 * HEX mangling format: \xNN, NN being the hex value of the character.
 * (whitelist and format supported by udev)
*/
typedef enum {
	DM_STRING_MANGLING_NONE, /* do not mangle at all */
	DM_STRING_MANGLING_AUTO, /* mangle only if not already mangled with hex, error when mixed */
	DM_STRING_MANGLING_HEX	 /* always mangle with hex encoding, no matter what the input is */
} dm_string_mangling_t;

/*
 * Set/get mangling mode used for device-mapper names and uuids.
 */
int dm_set_name_mangling_mode(dm_string_mangling_t name_mangling);
dm_string_mangling_t dm_get_name_mangling_mode(void);

/*
 * Get mangled/unmangled form of the device-mapper name or uuid
 * irrespective of the global setting (set by dm_set_name_mangling_mode).
 * The name or uuid returned needs to be freed after use by calling dm_free!
 */
char *dm_task_get_name_mangled(const struct dm_task *dmt);
char *dm_task_get_name_unmangled(const struct dm_task *dmt);
char *dm_task_get_uuid_mangled(const struct dm_task *dmt);
char *dm_task_get_uuid_unmangled(const struct dm_task *dmt);

/*
 * Configure the device-mapper directory
 */
int dm_set_dev_dir(const char *dir);
const char *dm_dir(void);

/*
 * Configure sysfs directory, /sys by default
 */
int dm_set_sysfs_dir(const char *dir);
const char *dm_sysfs_dir(void);

/*
 * Configure default UUID prefix string.
 * Conventionally this is a short capitalised prefix indicating the subsystem
 * that is managing the devices, e.g. "LVM-" or "MPATH-".
 * To support stacks of devices from different subsystems, recursive functions
 * stop recursing if they reach a device with a different prefix.
 */
int dm_set_uuid_prefix(const char *uuid_prefix);
const char *dm_uuid_prefix(void);

/*
 * Determine whether a major number belongs to device-mapper or not.
 */
int dm_is_dm_major(uint32_t major);

/*
 * Get associated device name for given major and minor number by reading
 * the sysfs content. If this is a dm device, get associated dm name, the one
 * that appears in /dev/mapper. DM names could be resolved this way only if
 * kernel used >= 2.6.29, kernel name is found otherwise (e.g. dm-0).
 * If prefer_kernel_name is set, the kernel name is always preferred over
 * device-mapper name for dm devices no matter what the kernel version is.
 * For non-dm devices, we always get associated kernel name, e.g sda, md0 etc.
 * Returns 0 on error or if sysfs is not used (or configured incorrectly),
 * otherwise returns 1 and the supplied buffer holds the device name.
 */
int dm_device_get_name(uint32_t major, uint32_t minor,
		       int prefer_kernel_name,
		       char *buf, size_t buf_size);

/*
 * Determine whether a device has any holders (devices
 * using this device). If sysfs is not used (or configured
 * incorrectly), returns 0.
 */
int dm_device_has_holders(uint32_t major, uint32_t minor);

/*
 * Determine whether a device contains mounted filesystem.
 * If sysfs is not used (or configured incorrectly), returns 0.
 */
int dm_device_has_mounted_fs(uint32_t major, uint32_t minor);


/*
 * Callback is invoked for individal mountinfo lines,
 * minor, major and mount target are parsed and unmangled.
 */
typedef int (*dm_mountinfo_line_callback_fn) (char *line, unsigned maj, unsigned min,
					      char *target, void *cb_data);

/*
 * Read all lines from /proc/self/mountinfo,
 * for each line calls read_fn callback.
 */
int dm_mountinfo_read(dm_mountinfo_line_callback_fn read_fn, void *cb_data);

/*
 * Initialise library
 */
void dm_lib_init(void) __attribute__((constructor));

/*
 * Release library resources
 */
void dm_lib_release(void);
void dm_lib_exit(void) __attribute__((destructor));

/*
 * Use NULL for all devices.
 */
int dm_mknodes(const char *name);
int dm_driver_version(char *version, size_t size);

/******************************************************
 * Functions to build and manipulate trees of devices *
 ******************************************************/
struct dm_tree;
struct dm_tree_node;

/*
 * Initialise an empty dependency tree.
 *
 * The tree consists of a root node together with one node for each mapped 
 * device which has child nodes for each device referenced in its table.
 *
 * Every node in the tree has one or more children and one or more parents.
 *
 * The root node is the parent/child of every node that doesn't have other 
 * parents/children.
 */
struct dm_tree *dm_tree_create(void);
void dm_tree_free(struct dm_tree *tree);

/*
 * Add nodes to the tree for a given device and all the devices it uses.
 */
int dm_tree_add_dev(struct dm_tree *tree, uint32_t major, uint32_t minor);
int dm_tree_add_dev_with_udev_flags(struct dm_tree *tree, uint32_t major,
				    uint32_t minor, uint16_t udev_flags);

/*
 * Add a new node to the tree if it doesn't already exist.
 */
struct dm_tree_node *dm_tree_add_new_dev(struct dm_tree *tree,
					 const char *name,
					 const char *uuid,
					 uint32_t major, uint32_t minor,
					 int read_only,
					 int clear_inactive,
					 void *context);
struct dm_tree_node *dm_tree_add_new_dev_with_udev_flags(struct dm_tree *tree,
							 const char *name,
							 const char *uuid,
							 uint32_t major,
							 uint32_t minor,
							 int read_only,
							 int clear_inactive,
							 void *context,
							 uint16_t udev_flags);

/*
 * Search for a node in the tree.
 * Set major and minor to 0 or uuid to NULL to get the root node.
 */
struct dm_tree_node *dm_tree_find_node(struct dm_tree *tree,
				       uint32_t major,
				       uint32_t minor);
struct dm_tree_node *dm_tree_find_node_by_uuid(struct dm_tree *tree,
					       const char *uuid);

/*
 * Use this to walk through all children of a given node.
 * Set handle to NULL in first call.
 * Returns NULL after the last child.
 * Set inverted to use inverted tree.
 */
struct dm_tree_node *dm_tree_next_child(void **handle,
					const struct dm_tree_node *parent,
					uint32_t inverted);

/*
 * Get properties of a node.
 */
const char *dm_tree_node_get_name(const struct dm_tree_node *node);
const char *dm_tree_node_get_uuid(const struct dm_tree_node *node);
const struct dm_info *dm_tree_node_get_info(const struct dm_tree_node *node);
void *dm_tree_node_get_context(const struct dm_tree_node *node);
int dm_tree_node_size_changed(const struct dm_tree_node *dnode);

/*
 * Returns the number of children of the given node (excluding the root node).
 * Set inverted for the number of parents.
 */
int dm_tree_node_num_children(const struct dm_tree_node *node, uint32_t inverted);

/*
 * Deactivate a device plus all dependencies.
 * Ignores devices that don't have a uuid starting with uuid_prefix.
 */
int dm_tree_deactivate_children(struct dm_tree_node *dnode,
				const char *uuid_prefix,
				size_t uuid_prefix_len);
/*
 * Preload/create a device plus all dependencies.
 * Ignores devices that don't have a uuid starting with uuid_prefix.
 */
int dm_tree_preload_children(struct dm_tree_node *dnode,
			     const char *uuid_prefix,
			     size_t uuid_prefix_len);

/*
 * Resume a device plus all dependencies.
 * Ignores devices that don't have a uuid starting with uuid_prefix.
 */
int dm_tree_activate_children(struct dm_tree_node *dnode,
			      const char *uuid_prefix,
			      size_t uuid_prefix_len);

/*
 * Suspend a device plus all dependencies.
 * Ignores devices that don't have a uuid starting with uuid_prefix.
 */
int dm_tree_suspend_children(struct dm_tree_node *dnode,
			     const char *uuid_prefix,
			     size_t uuid_prefix_len);

/*
 * Skip the filesystem sync when suspending.
 * Does nothing with other functions.
 * Use this when no snapshots are involved.
 */ 
void dm_tree_skip_lockfs(struct dm_tree_node *dnode);

/*
 * Set the 'noflush' flag when suspending devices.
 * If the kernel supports it, instead of erroring outstanding I/O that
 * cannot be completed, the I/O is queued and resubmitted when the
 * device is resumed.  This affects multipath devices when all paths
 * have failed and queue_if_no_path is set, and mirror devices when
 * block_on_error is set and the mirror log has failed.
 */
void dm_tree_use_no_flush_suspend(struct dm_tree_node *dnode);

/*
 * Retry removal of each device if not successful.
 */
void dm_tree_retry_remove(struct dm_tree_node *dnode);

/*
 * Is the uuid prefix present in the tree?
 * Only returns 0 if every node was checked successfully.
 * Returns 1 if the tree walk has to be aborted.
 */
int dm_tree_children_use_uuid(struct dm_tree_node *dnode,
			      const char *uuid_prefix,
			      size_t uuid_prefix_len);

/*
 * Construct tables for new nodes before activating them.
 */
int dm_tree_node_add_snapshot_origin_target(struct dm_tree_node *dnode,
					    uint64_t size,
					    const char *origin_uuid);
int dm_tree_node_add_snapshot_target(struct dm_tree_node *node,
				     uint64_t size,
				     const char *origin_uuid,
				     const char *cow_uuid,
				     int persistent,
				     uint32_t chunk_size);
int dm_tree_node_add_snapshot_merge_target(struct dm_tree_node *node,
					   uint64_t size,
					   const char *origin_uuid,
					   const char *cow_uuid,
					   const char *merge_uuid,
					   uint32_t chunk_size);
int dm_tree_node_add_error_target(struct dm_tree_node *node,
				  uint64_t size);
int dm_tree_node_add_zero_target(struct dm_tree_node *node,
				 uint64_t size);
int dm_tree_node_add_linear_target(struct dm_tree_node *node,
				   uint64_t size);
int dm_tree_node_add_striped_target(struct dm_tree_node *node,
				    uint64_t size,
				    uint32_t stripe_size);

#define DM_CRYPT_IV_DEFAULT	UINT64_C(-1)	/* iv_offset == seg offset */
/*
 * Function accepts one string in cipher specification
 * (chainmode and iv should be NULL because included in cipher string)
 *   or
 * separate arguments which will be joined to "cipher-chainmode-iv"
 */
int dm_tree_node_add_crypt_target(struct dm_tree_node *node,
				  uint64_t size,
				  const char *cipher,
				  const char *chainmode,
				  const char *iv,
				  uint64_t iv_offset,
				  const char *key);
int dm_tree_node_add_mirror_target(struct dm_tree_node *node,
				   uint64_t size);
 
/* Mirror log flags */
#define DM_NOSYNC		0x00000001	/* Known already in sync */
#define DM_FORCESYNC		0x00000002	/* Force resync */
#define DM_BLOCK_ON_ERROR	0x00000004	/* On error, suspend I/O */
#define DM_CORELOG		0x00000008	/* In-memory log */

int dm_tree_node_add_mirror_target_log(struct dm_tree_node *node,
				       uint32_t region_size,
				       unsigned clustered,
				       const char *log_uuid,
				       unsigned area_count,
				       uint32_t flags);

int dm_tree_node_add_raid_target(struct dm_tree_node *node,
				 uint64_t size,
				 const char *raid_type,
				 uint32_t region_size,
				 uint32_t stripe_size,
				 uint64_t rebuilds,
				 uint64_t flags);

/*
 * Defines bellow are based on kernel's dm-cache.c defines
 * DM_CACHE_MIN_DATA_BLOCK_SIZE (32 * 1024 >> SECTOR_SHIFT)
 * DM_CACHE_MAX_DATA_BLOCK_SIZE (1024 * 1024 * 1024 >> SECTOR_SHIFT)
 */
#define DM_CACHE_MIN_DATA_BLOCK_SIZE (UINT32_C(64))
#define DM_CACHE_MAX_DATA_BLOCK_SIZE (UINT32_C(2097152))
/*
 * Max supported size for cache pool metadata device.
 * Limitation is hardcoded into the kernel and bigger device sizes
 * are not accepted.
 *
 * Limit defined in drivers/md/dm-cache-metadata.h
 */
#define DM_CACHE_METADATA_MAX_SECTORS DM_THIN_METADATA_MAX_SECTORS

struct dm_tree_node_raid_params {
	const char *raid_type;

	uint32_t stripes;
	uint32_t mirrors;
	uint32_t region_size;
	uint32_t stripe_size;

	/*
	 * 'rebuilds' and 'writemostly' are bitfields that signify
	 * which devices in the array are to be rebuilt or marked
	 * writemostly.  By choosing a 'uint64_t', we limit ourself
	 * to RAID arrays with 64 devices.
	 */
	uint64_t rebuilds;
	uint64_t writemostly;
	uint32_t writebehind;       /* I/Os (kernel default COUNTER_MAX / 2) */
	uint32_t sync_daemon_sleep; /* ms (kernel default = 5sec) */
	uint32_t max_recovery_rate; /* kB/sec/disk */
	uint32_t min_recovery_rate; /* kB/sec/disk */
	uint32_t stripe_cache;      /* sectors */

	uint64_t flags;             /* [no]sync */
	uint64_t reserved2;
};

int dm_tree_node_add_raid_target_with_params(struct dm_tree_node *node,
					     uint64_t size,
					     struct dm_tree_node_raid_params *p);

/* Cache feature_flags */
#define DM_CACHE_FEATURE_WRITEBACK    0x00000001
#define DM_CACHE_FEATURE_WRITETHROUGH 0x00000002

int dm_tree_node_add_cache_target(struct dm_tree_node *node,
				  uint64_t size,
				  const char *metadata_uuid,
				  const char *data_uuid,
				  const char *origin_uuid,
				  uint32_t chunk_size,
				  uint32_t feature_flags, /* DM_CACHE_FEATURE_* */
				  unsigned core_argc,
				  const char *const *core_argv,
				  const char *policy_name,
				  unsigned policy_argc,
				  const char *const *policy_argv);

/*
 * Replicator operation mode
 * Note: API for Replicator is not yet stable
 */
typedef enum {
	DM_REPLICATOR_SYNC,			/* Synchronous replication */
	DM_REPLICATOR_ASYNC_WARN,		/* Warn if async replicator is slow */
	DM_REPLICATOR_ASYNC_STALL,		/* Stall replicator if not fast enough */
	DM_REPLICATOR_ASYNC_DROP,		/* Drop sites out of sync */
	DM_REPLICATOR_ASYNC_FAIL,		/* Fail replicator if slow */
	NUM_DM_REPLICATOR_MODES
} dm_replicator_mode_t;

int dm_tree_node_add_replicator_target(struct dm_tree_node *node,
				       uint64_t size,
				       const char *rlog_uuid,
				       const char *rlog_type,
				       unsigned rsite_index,
				       dm_replicator_mode_t mode,
				       uint32_t async_timeout,
				       uint64_t fall_behind_data,
				       uint32_t fall_behind_ios);

int dm_tree_node_add_replicator_dev_target(struct dm_tree_node *node,
					   uint64_t size,
					   const char *replicator_uuid,	/* Replicator control device */
					   uint64_t rdevice_index,
					   const char *rdev_uuid,	/* Rimage device name/uuid */
					   unsigned rsite_index,
					   const char *slog_uuid,
					   uint32_t slog_flags,		/* Mirror log flags */
					   uint32_t slog_region_size);
/* End of Replicator API */

/*
 * FIXME: Defines bellow are based on kernel's dm-thin.c defines
 * DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
 * DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
 */
#define DM_THIN_MIN_DATA_BLOCK_SIZE (UINT32_C(128))
#define DM_THIN_MAX_DATA_BLOCK_SIZE (UINT32_C(2097152))
/*
 * Max supported size for thin pool  metadata device (17112760320 bytes)
 * Limitation is hardcoded into the kernel and bigger device size
 * is not accepted.
 * drivers/md/dm-thin-metadata.h THIN_METADATA_MAX_SECTORS
 */
#define DM_THIN_MAX_METADATA_SIZE   (UINT64_C(255) * (1 << 14) * (4096 / (1 << 9)) - 256 * 1024)

int dm_tree_node_add_thin_pool_target(struct dm_tree_node *node,
				      uint64_t size,
				      uint64_t transaction_id,
				      const char *metadata_uuid,
				      const char *pool_uuid,
				      uint32_t data_block_size,
				      uint64_t low_water_mark,
				      unsigned skip_block_zeroing);

/* Supported messages for thin provision target */
typedef enum {
	DM_THIN_MESSAGE_CREATE_SNAP,		/* device_id, origin_id */
	DM_THIN_MESSAGE_CREATE_THIN,		/* device_id */
	DM_THIN_MESSAGE_DELETE,			/* device_id */
	DM_THIN_MESSAGE_SET_TRANSACTION_ID,	/* current_id, new_id */
	DM_THIN_MESSAGE_RESERVE_METADATA_SNAP,	/* target version >= 1.1 */
	DM_THIN_MESSAGE_RELEASE_METADATA_SNAP,	/* target version >= 1.1 */
} dm_thin_message_t;

int dm_tree_node_add_thin_pool_message(struct dm_tree_node *node,
				       dm_thin_message_t type,
				       uint64_t id1, uint64_t id2);

/*
 * Set thin pool discard features
 *   ignore      - Disable support for discards
 *   no_passdown - Don't pass discards down to underlying data device,
 *                 just remove the mapping
 * Feature is available since version 1.1 of the thin target.
 */
int dm_tree_node_set_thin_pool_discard(struct dm_tree_node *node,
				       unsigned ignore,
				       unsigned no_passdown);

/*
 * FIXME: Defines bellow are based on kernel's dm-thin.c defines
 * MAX_DEV_ID ((1 << 24) - 1)
 */
#define DM_THIN_MAX_DEVICE_ID (UINT32_C((1 << 24) - 1))
int dm_tree_node_add_thin_target(struct dm_tree_node *node,
				 uint64_t size,
				 const char *pool_uuid,
				 uint32_t device_id);

int dm_tree_node_set_thin_external_origin(struct dm_tree_node *node,
					  const char *external_uuid);

void dm_tree_node_set_udev_flags(struct dm_tree_node *node, uint16_t udev_flags);

void dm_tree_node_set_presuspend_node(struct dm_tree_node *node,
				      struct dm_tree_node *presuspend_node);

int dm_tree_node_add_target_area(struct dm_tree_node *node,
				    const char *dev_name,
				    const char *dlid,
				    uint64_t offset);

/*
 * Only for temporarily-missing raid devices where changes are tracked.
 */
int dm_tree_node_add_null_area(struct dm_tree_node *node, uint64_t offset);

/*
 * Set readahead (in sectors) after loading the node.
 */
void dm_tree_node_set_read_ahead(struct dm_tree_node *dnode,
				 uint32_t read_ahead,
				 uint32_t read_ahead_flags);

/*
 * Set node callback hook before de/activation.
 * Callback is called before 'activation' of node for activation tree,
 * or 'deactivation' of node for deactivation tree.
 */
typedef enum {
	DM_NODE_CALLBACK_PRELOADED,   /* Node has preload deps */
	DM_NODE_CALLBACK_DEACTIVATED, /* Node is deactivated */
} dm_node_callback_t;
typedef int (*dm_node_callback_fn) (struct dm_tree_node *node,
				    dm_node_callback_t type, void *cb_data);
void dm_tree_node_set_callback(struct dm_tree_node *node,
			       dm_node_callback_fn cb, void *cb_data);

void dm_tree_set_cookie(struct dm_tree_node *node, uint32_t cookie);
uint32_t dm_tree_get_cookie(struct dm_tree_node *node);

/*****************************************************************************
 * Library functions
 *****************************************************************************/

/*******************
 * Memory management
 *******************/

void *dm_malloc_aux(size_t s, const char *file, int line)
	__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void *dm_malloc_aux_debug(size_t s, const char *file, int line)
	__attribute__((__warn_unused_result__));
void *dm_zalloc_aux(size_t s, const char *file, int line)
	__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void *dm_zalloc_aux_debug(size_t s, const char *file, int line)
	__attribute__((__warn_unused_result__));
char *dm_strdup_aux(const char *str, const char *file, int line)
	__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void dm_free_aux(void *p);
void *dm_realloc_aux(void *p, unsigned int s, const char *file, int line)
	__attribute__((__warn_unused_result__));
int dm_dump_memory_debug(void);
void dm_bounds_check_debug(void);

#ifdef DEBUG_MEM

#  define dm_malloc(s) dm_malloc_aux_debug((s), __FILE__, __LINE__)
#  define dm_zalloc(s) dm_zalloc_aux_debug((s), __FILE__, __LINE__)
#  define dm_strdup(s) dm_strdup_aux((s), __FILE__, __LINE__)
#  define dm_free(p) dm_free_aux(p)
#  define dm_realloc(p, s) dm_realloc_aux(p, s, __FILE__, __LINE__)
#  define dm_dump_memory() dm_dump_memory_debug()
#  define dm_bounds_check() dm_bounds_check_debug()

#else

#  define dm_malloc(s) dm_malloc_aux((s), __FILE__, __LINE__)
#  define dm_zalloc(s) dm_zalloc_aux((s), __FILE__, __LINE__)
#  define dm_strdup(s) strdup(s)
#  define dm_free(p) free(p)
#  define dm_realloc(p, s) realloc(p, s)
#  define dm_dump_memory() {}
#  define dm_bounds_check() {}

#endif


/*
 * The pool allocator is useful when you are going to allocate
 * lots of memory, use the memory for a bit, and then free the
 * memory in one go.  A surprising amount of code has this usage
 * profile.
 *
 * You should think of the pool as an infinite, contiguous chunk
 * of memory.  The front of this chunk of memory contains
 * allocated objects, the second half is free.  dm_pool_alloc grabs
 * the next 'size' bytes from the free half, in effect moving it
 * into the allocated half.  This operation is very efficient.
 *
 * dm_pool_free frees the allocated object *and* all objects
 * allocated after it.  It is important to note this semantic
 * difference from malloc/free.  This is also extremely
 * efficient, since a single dm_pool_free can dispose of a large
 * complex object.
 *
 * dm_pool_destroy frees all allocated memory.
 *
 * eg, If you are building a binary tree in your program, and
 * know that you are only ever going to insert into your tree,
 * and not delete (eg, maintaining a symbol table for a
 * compiler).  You can create yourself a pool, allocate the nodes
 * from it, and when the tree becomes redundant call dm_pool_destroy
 * (no nasty iterating through the tree to free nodes).
 *
 * eg, On the other hand if you wanted to repeatedly insert and
 * remove objects into the tree, you would be better off
 * allocating the nodes from a free list; you cannot free a
 * single arbitrary node with pool.
 */

struct dm_pool;

/* constructor and destructor */
struct dm_pool *dm_pool_create(const char *name, size_t chunk_hint)
	__attribute__((__warn_unused_result__));
void dm_pool_destroy(struct dm_pool *p);

/* simple allocation/free routines */
void *dm_pool_alloc(struct dm_pool *p, size_t s)
	__attribute__((__warn_unused_result__));
void *dm_pool_alloc_aligned(struct dm_pool *p, size_t s, unsigned alignment)
	__attribute__((__warn_unused_result__));
void dm_pool_empty(struct dm_pool *p);
void dm_pool_free(struct dm_pool *p, void *ptr);

/*
 * To aid debugging, a pool can be locked. Any modifications made
 * to the content of the pool while it is locked can be detected.
 * Default compilation is using a crc checksum to notice modifications.
 * The pool locking is using the mprotect with the compilation flag
 * DEBUG_ENFORCE_POOL_LOCKING to enforce the memory protection.
 */
/* query pool lock status */
int dm_pool_locked(struct dm_pool *p);
/* mark pool as locked */
int dm_pool_lock(struct dm_pool *p, int crc)
	__attribute__((__warn_unused_result__));
/* mark pool as unlocked */
int dm_pool_unlock(struct dm_pool *p, int crc)
	__attribute__((__warn_unused_result__));

/*
 * Object building routines:
 *
 * These allow you to 'grow' an object, useful for
 * building strings, or filling in dynamic
 * arrays.
 *
 * It's probably best explained with an example:
 *
 * char *build_string(struct dm_pool *mem)
 * {
 *      int i;
 *      char buffer[16];
 *
 *      if (!dm_pool_begin_object(mem, 128))
 *              return NULL;
 *
 *      for (i = 0; i < 50; i++) {
 *              snprintf(buffer, sizeof(buffer), "%d, ", i);
 *              if (!dm_pool_grow_object(mem, buffer, 0))
 *                      goto bad;
 *      }
 *
 *	// add null
 *      if (!dm_pool_grow_object(mem, "\0", 1))
 *              goto bad;
 *
 *      return dm_pool_end_object(mem);
 *
 * bad:
 *
 *      dm_pool_abandon_object(mem);
 *      return NULL;
 *}
 *
 * So start an object by calling dm_pool_begin_object
 * with a guess at the final object size - if in
 * doubt make the guess too small.
 *
 * Then append chunks of data to your object with
 * dm_pool_grow_object.  Finally get your object with
 * a call to dm_pool_end_object.
 *
 * Setting delta to 0 means it will use strlen(extra).
 */
int dm_pool_begin_object(struct dm_pool *p, size_t hint);
int dm_pool_grow_object(struct dm_pool *p, const void *extra, size_t delta);
void *dm_pool_end_object(struct dm_pool *p);
void dm_pool_abandon_object(struct dm_pool *p);

/* utilities */
char *dm_pool_strdup(struct dm_pool *p, const char *str)
	__attribute__((__warn_unused_result__));
char *dm_pool_strndup(struct dm_pool *p, const char *str, size_t n)
	__attribute__((__warn_unused_result__));
void *dm_pool_zalloc(struct dm_pool *p, size_t s)
	__attribute__((__warn_unused_result__));

/******************
 * bitset functions
 ******************/

typedef uint32_t *dm_bitset_t;

dm_bitset_t dm_bitset_create(struct dm_pool *mem, unsigned num_bits);
void dm_bitset_destroy(dm_bitset_t bs);

int dm_bitset_equal(dm_bitset_t in1, dm_bitset_t in2);

void dm_bit_and(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2);
void dm_bit_union(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2);
int dm_bit_get_first(dm_bitset_t bs);
int dm_bit_get_next(dm_bitset_t bs, int last_bit);

#define DM_BITS_PER_INT (sizeof(int) * CHAR_BIT)

#define dm_bit(bs, i) \
   ((bs)[((i) / DM_BITS_PER_INT) + 1] & (0x1 << ((i) & (DM_BITS_PER_INT - 1))))

#define dm_bit_set(bs, i) \
   ((bs)[((i) / DM_BITS_PER_INT) + 1] |= (0x1 << ((i) & (DM_BITS_PER_INT - 1))))

#define dm_bit_clear(bs, i) \
   ((bs)[((i) / DM_BITS_PER_INT) + 1] &= ~(0x1 << ((i) & (DM_BITS_PER_INT - 1))))

#define dm_bit_set_all(bs) \
   memset((bs) + 1, -1, ((*(bs) / DM_BITS_PER_INT) + 1) * sizeof(int))

#define dm_bit_clear_all(bs) \
   memset((bs) + 1, 0, ((*(bs) / DM_BITS_PER_INT) + 1) * sizeof(int))

#define dm_bit_copy(bs1, bs2) \
   memcpy((bs1) + 1, (bs2) + 1, ((*(bs1) / DM_BITS_PER_INT) + 1) * sizeof(int))

/* Returns number of set bits */
static inline unsigned hweight32(uint32_t i)
{
	unsigned r = (i & 0x55555555) + ((i >> 1) & 0x55555555);

	r =    (r & 0x33333333) + ((r >>  2) & 0x33333333);
	r =    (r & 0x0F0F0F0F) + ((r >>  4) & 0x0F0F0F0F);
	r =    (r & 0x00FF00FF) + ((r >>  8) & 0x00FF00FF);
	return (r & 0x0000FFFF) + ((r >> 16) & 0x0000FFFF);
}

/****************
 * hash functions
 ****************/

struct dm_hash_table;
struct dm_hash_node;

typedef void (*dm_hash_iterate_fn) (void *data);

struct dm_hash_table *dm_hash_create(unsigned size_hint)
	__attribute__((__warn_unused_result__));
void dm_hash_destroy(struct dm_hash_table *t);
void dm_hash_wipe(struct dm_hash_table *t);

void *dm_hash_lookup(struct dm_hash_table *t, const char *key);
int dm_hash_insert(struct dm_hash_table *t, const char *key, void *data);
void dm_hash_remove(struct dm_hash_table *t, const char *key);

void *dm_hash_lookup_binary(struct dm_hash_table *t, const void *key, uint32_t len);
int dm_hash_insert_binary(struct dm_hash_table *t, const void *key, uint32_t len,
			  void *data);
void dm_hash_remove_binary(struct dm_hash_table *t, const void *key, uint32_t len);

unsigned dm_hash_get_num_entries(struct dm_hash_table *t);
void dm_hash_iter(struct dm_hash_table *t, dm_hash_iterate_fn f);

char *dm_hash_get_key(struct dm_hash_table *t, struct dm_hash_node *n);
void *dm_hash_get_data(struct dm_hash_table *t, struct dm_hash_node *n);
struct dm_hash_node *dm_hash_get_first(struct dm_hash_table *t);
struct dm_hash_node *dm_hash_get_next(struct dm_hash_table *t, struct dm_hash_node *n);

#define dm_hash_iterate(v, h) \
	for (v = dm_hash_get_first((h)); v; \
	     v = dm_hash_get_next((h), v))

/****************
 * list functions
 ****************/

/*
 * A list consists of a list head plus elements.
 * Each element has 'next' and 'previous' pointers.
 * The list head's pointers point to the first and the last element.
 */

struct dm_list {
	struct dm_list *n, *p;
};

/*
 * String list.
 */
struct dm_str_list {
	struct dm_list list;
	const char *str;
};

/*
 * Initialise a list before use.
 * The list head's next and previous pointers point back to itself.
 */
#define DM_LIST_INIT(name)	struct dm_list name = { &(name), &(name) }
void dm_list_init(struct dm_list *head);

/*
 * Insert an element before 'head'.
 * If 'head' is the list head, this adds an element to the end of the list.
 */
void dm_list_add(struct dm_list *head, struct dm_list *elem);

/*
 * Insert an element after 'head'.
 * If 'head' is the list head, this adds an element to the front of the list.
 */
void dm_list_add_h(struct dm_list *head, struct dm_list *elem);

/*
 * Delete an element from its list.
 * Note that this doesn't change the element itself - it may still be safe
 * to follow its pointers.
 */
void dm_list_del(struct dm_list *elem);

/*
 * Remove an element from existing list and insert before 'head'.
 */
void dm_list_move(struct dm_list *head, struct dm_list *elem);

/*
 * Join 'head1' to the end of 'head'.
 */
void dm_list_splice(struct dm_list *head, struct dm_list *head1);

/*
 * Is the list empty?
 */
int dm_list_empty(const struct dm_list *head);

/*
 * Is this the first element of the list?
 */
int dm_list_start(const struct dm_list *head, const struct dm_list *elem);

/*
 * Is this the last element of the list?
 */
int dm_list_end(const struct dm_list *head, const struct dm_list *elem);

/*
 * Return first element of the list or NULL if empty
 */
struct dm_list *dm_list_first(const struct dm_list *head);

/*
 * Return last element of the list or NULL if empty
 */
struct dm_list *dm_list_last(const struct dm_list *head);

/*
 * Return the previous element of the list, or NULL if we've reached the start.
 */
struct dm_list *dm_list_prev(const struct dm_list *head, const struct dm_list *elem);

/*
 * Return the next element of the list, or NULL if we've reached the end.
 */
struct dm_list *dm_list_next(const struct dm_list *head, const struct dm_list *elem);

/*
 * Given the address v of an instance of 'struct dm_list' called 'head' 
 * contained in a structure of type t, return the containing structure.
 */
#define dm_list_struct_base(v, t, head) \
    ((t *)((const char *)(v) - (const char *)&((t *) 0)->head))

/*
 * Given the address v of an instance of 'struct dm_list list' contained in
 * a structure of type t, return the containing structure.
 */
#define dm_list_item(v, t) dm_list_struct_base((v), t, list)

/*
 * Given the address v of one known element e in a known structure of type t,
 * return another element f.
 */
#define dm_struct_field(v, t, e, f) \
    (((t *)((uintptr_t)(v) - (uintptr_t)&((t *) 0)->e))->f)

/*
 * Given the address v of a known element e in a known structure of type t,
 * return the list head 'list'
 */
#define dm_list_head(v, t, e) dm_struct_field(v, t, e, list)

/*
 * Set v to each element of a list in turn.
 */
#define dm_list_iterate(v, head) \
	for (v = (head)->n; v != head; v = v->n)

/*
 * Set v to each element in a list in turn, starting from the element 
 * in front of 'start'.
 * You can use this to 'unwind' a list_iterate and back out actions on
 * already-processed elements.
 * If 'start' is 'head' it walks the list backwards.
 */
#define dm_list_uniterate(v, head, start) \
	for (v = (start)->p; v != head; v = v->p)

/*
 * A safe way to walk a list and delete and free some elements along
 * the way.
 * t must be defined as a temporary variable of the same type as v.
 */
#define dm_list_iterate_safe(v, t, head) \
	for (v = (head)->n, t = v->n; v != head; v = t, t = v->n)

/*
 * Walk a list, setting 'v' in turn to the containing structure of each item.
 * The containing structure should be the same type as 'v'.
 * The 'struct dm_list' variable within the containing structure is 'field'.
 */
#define dm_list_iterate_items_gen(v, head, field) \
	for (v = dm_list_struct_base((head)->n, __typeof__(*v), field); \
	     &v->field != (head); \
	     v = dm_list_struct_base(v->field.n, __typeof__(*v), field))

/*
 * Walk a list, setting 'v' in turn to the containing structure of each item.
 * The containing structure should be the same type as 'v'.
 * The list should be 'struct dm_list list' within the containing structure.
 */
#define dm_list_iterate_items(v, head) dm_list_iterate_items_gen(v, (head), list)

/*
 * Walk a list, setting 'v' in turn to the containing structure of each item.
 * The containing structure should be the same type as 'v'.
 * The 'struct dm_list' variable within the containing structure is 'field'.
 * t must be defined as a temporary variable of the same type as v.
 */
#define dm_list_iterate_items_gen_safe(v, t, head, field) \
	for (v = dm_list_struct_base((head)->n, __typeof__(*v), field), \
	     t = dm_list_struct_base(v->field.n, __typeof__(*v), field); \
	     &v->field != (head); \
	     v = t, t = dm_list_struct_base(v->field.n, __typeof__(*v), field))
/*
 * Walk a list, setting 'v' in turn to the containing structure of each item.
 * The containing structure should be the same type as 'v'.
 * The list should be 'struct dm_list list' within the containing structure.
 * t must be defined as a temporary variable of the same type as v.
 */
#define dm_list_iterate_items_safe(v, t, head) \
	dm_list_iterate_items_gen_safe(v, t, (head), list)

/*
 * Walk a list backwards, setting 'v' in turn to the containing structure 
 * of each item.
 * The containing structure should be the same type as 'v'.
 * The 'struct dm_list' variable within the containing structure is 'field'.
 */
#define dm_list_iterate_back_items_gen(v, head, field) \
	for (v = dm_list_struct_base((head)->p, __typeof__(*v), field); \
	     &v->field != (head); \
	     v = dm_list_struct_base(v->field.p, __typeof__(*v), field))

/*
 * Walk a list backwards, setting 'v' in turn to the containing structure 
 * of each item.
 * The containing structure should be the same type as 'v'.
 * The list should be 'struct dm_list list' within the containing structure.
 */
#define dm_list_iterate_back_items(v, head) dm_list_iterate_back_items_gen(v, (head), list)

/*
 * Return the number of elements in a list by walking it.
 */
unsigned int dm_list_size(const struct dm_list *head);

/*********
 * selinux
 *********/

/*
 * Obtain SELinux security context assigned for the path and set this
 * context for creating a new file system object. This security context
 * is global and it is used until reset to default policy behaviour
 * by calling 'dm_prepare_selinux_context(NULL, 0)'.
 */
int dm_prepare_selinux_context(const char *path, mode_t mode);
/*
 * Set SELinux context for existing file system object.
 */
int dm_set_selinux_context(const char *path, mode_t mode);

/*********************
 * string manipulation
 *********************/

/*
 * Break up the name of a mapped device into its constituent
 * Volume Group, Logical Volume and Layer (if present).
 * If mem is supplied, the result is allocated from the mempool.
 * Otherwise the strings are changed in situ.
 */
int dm_split_lvm_name(struct dm_pool *mem, const char *dmname,
		      char **vgname, char **lvname, char **layer);

/*
 * Destructively split buffer into NULL-separated words in argv.
 * Returns number of words.
 */
int dm_split_words(char *buffer, unsigned max,
		   unsigned ignore_comments, /* Not implemented */
		   char **argv);

/* 
 * Returns -1 if buffer too small
 */
int dm_snprintf(char *buf, size_t bufsize, const char *format, ...)
    __attribute__ ((format(printf, 3, 4)));

/*
 * Returns pointer to the last component of the path.
 */
const char *dm_basename(const char *path);

/*
 * Returns number of occurrences of 'c' in 'str' of length 'size'.
 */
unsigned dm_count_chars(const char *str, size_t len, const int c);

/*
 * Length of string after escaping double quotes and backslashes.
 */
size_t dm_escaped_len(const char *str);

/*
 * <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
 */
char *dm_build_dm_name(struct dm_pool *mem, const char *vgname,
		       const char *lvname, const char *layer);
char *dm_build_dm_uuid(struct dm_pool *mem, const char *prefix, const char *lvid, const char *layer);

/*
 * Copies a string, quoting double quotes with backslashes.
 */
char *dm_escape_double_quotes(char *out, const char *src);

/*
 * Undo quoting in situ.
 */
void dm_unescape_double_quotes(char *src);

/*
 * Unescape colons and "at" signs in situ and save the substrings
 * starting at the position of the first unescaped colon and the
 * first unescaped "at" sign. This is normally used to unescape
 * device names used as PVs.
 */
void dm_unescape_colons_and_at_signs(char *src,
				     char **substr_first_unquoted_colon,
				     char **substr_first_unquoted_at_sign);

/*
 * Replacement for strncpy() function.
 *
 * Copies no more than n bytes from string pointed by src to the buffer
 * pointed by dest and ensure string is finished with '\0'.
 * Returns 0 if the whole string does not fit.
 */
int dm_strncpy(char *dest, const char *src, size_t n);

/*
 * Recognize unit specifier in the 'units' arg and return a factor
 * representing that unit. If the 'units' contains a prefix with digits,
 * the 'units' is considered to be a custom unit.
 *
 * Also, set 'unit_type' output arg to the character that represents
 * the unit specified. The 'unit_type' character equals to the unit
 * character itself recognized in the 'units' arg for canonical units.
 * Otherwise, the 'unit_type' character is set to 'U' for custom unit.
 *
 * An example for k/K canonical units and 8k/8K custom units:
 *
 *   units  unit_type  return value (factor)
 *   k      k          1024
 *   K      K          1000
 *   8k     U          1024*8
 *   8K     U          1000*8
 *   etc...
 *
 * Recognized units:
 *
 *   h/H - human readable (returns 1 for both)
 *   b/B - byte (returns 1 for both)
 *   s/S - sector (returns 512 for both)
 *   k/K - kilo (returns 1024/1000 respectively)
 *   m/M - mega (returns 1024^2/1000^2 respectively)
 *   g/G - giga (returns 1024^3/1000^3 respectively)
 *   t/T - tera (returns 1024^4/1000^4 respectively)
 *   p/P - peta (returns 1024^5/1000^5 respectively)
 *   e/E - exa (returns 1024^6/1000^6 respectively)
 *
 * Only one units character is allowed in the 'units' arg
 * if strict mode is enabled by 'strict' arg.
 *
 * The 'endptr' output arg, if not NULL, saves the pointer
 * in the 'units' string which follows the unit specifier
 * recognized (IOW the position where the parsing of the
 * unit specifier stopped).
 *
 * Returns the unit factor or 0 if no unit is recognized.
 */
uint64_t dm_units_to_factor(const char *units, char *unit_type,
			    int strict, const char **endptr);

/**************************
 * file/stream manipulation
 **************************/

/*
 * Create a directory (with parent directories if necessary).
 * Returns 1 on success, 0 on failure.
 */
int dm_create_dir(const char *dir);

int dm_is_empty_dir(const char *dir);

/*
 * Close a stream, with nicer error checking than fclose's.
 * Derived from gnulib's close-stream.c.
 *
 * Close "stream".  Return 0 if successful, and EOF (setting errno)
 * otherwise.  Upon failure, set errno to 0 if the error number
 * cannot be determined.  Useful mainly for writable streams.
 */
int dm_fclose(FILE *stream);

/*
 * Returns size of a buffer which is allocated with dm_malloc.
 * Pointer to the buffer is stored in *buf.
 * Returns -1 on failure leaving buf undefined.
 */
int dm_asprintf(char **buf, const char *format, ...)
    __attribute__ ((format(printf, 2, 3)));
int dm_vasprintf(char **buf, const char *format, va_list ap)
    __attribute__ ((format(printf, 2, 0)));

/*
 * create lockfile (pidfile) - create and lock a lock file
 * @lockfile: location of lock file
 *
 * Returns: 1 on success, 0 otherwise, errno is handled internally
 */
int dm_create_lockfile(const char* lockfile);

/*
 * Query whether a daemon is running based on its lockfile
 *
 * Returns: 1 if running, 0 if not
 */
int dm_daemon_is_running(const char* lockfile);

/*********************
 * regular expressions
 *********************/
struct dm_regex;

/*
 * Initialise an array of num patterns for matching.
 * Uses memory from mem.
 */
struct dm_regex *dm_regex_create(struct dm_pool *mem, const char * const *patterns,
				 unsigned num_patterns);

/*
 * Match string s against the patterns.
 * Returns the index of the highest pattern in the array that matches,
 * or -1 if none match.
 */
int dm_regex_match(struct dm_regex *regex, const char *s);

/*
 * This is useful for regression testing only.  The idea is if two
 * fingerprints are different, then the two dfas are certainly not
 * isomorphic.  If two fingerprints _are_ the same then it's very likely
 * that the dfas are isomorphic.
 *
 * This function must be called before any matching is done.
 */
uint32_t dm_regex_fingerprint(struct dm_regex *regex);

/******************
 * percent handling
 ******************/
/*
 * A fixed-point representation of percent values. One percent equals to
 * DM_PERCENT_1 as defined below. Values that are not multiples of DM_PERCENT_1
 * represent fractions, with precision of 1/1000000 of a percent. See
 * dm_percent_to_float for a conversion to a floating-point representation.
 *
 * You should always use dm_make_percent when building dm_percent_t values. The
 * implementation of dm_make_percent is biased towards the middle: it ensures that
 * the result is DM_PERCENT_0 or DM_PERCENT_100 if and only if this is the actual
 * value -- it never rounds any intermediate value (> 0 or < 100) to either 0
 * or 100.
*/
#define DM_PERCENT_CHAR '%'

typedef enum {
	DM_PERCENT_0 = 0,
	DM_PERCENT_1 = 1000000,
	DM_PERCENT_100 = 100 * DM_PERCENT_1,
	DM_PERCENT_INVALID = -1,
	DM_PERCENT_FAILED = -2
} dm_percent_range_t;

typedef int32_t dm_percent_t;

float dm_percent_to_float(dm_percent_t percent);
dm_percent_t dm_make_percent(uint64_t numerator, uint64_t denominator);

/*********************
 * reporting functions
 *********************/

struct dm_report_object_type {
	uint32_t id;			/* Powers of 2 */
	const char *desc;
	const char *prefix;		/* field id string prefix (optional) */
	void *(*data_fn)(void *object);	/* callback from report_object() */
};

struct dm_report_field;

/*
 * dm_report_field_type flags
 */
#define DM_REPORT_FIELD_MASK			0x00000FFF
#define DM_REPORT_FIELD_ALIGN_MASK		0x0000000F
#define DM_REPORT_FIELD_ALIGN_LEFT		0x00000001
#define DM_REPORT_FIELD_ALIGN_RIGHT		0x00000002
#define DM_REPORT_FIELD_TYPE_MASK		0x00000FF0
#define DM_REPORT_FIELD_TYPE_NONE		0x00000000
#define DM_REPORT_FIELD_TYPE_STRING		0x00000010
#define DM_REPORT_FIELD_TYPE_NUMBER		0x00000020
#define DM_REPORT_FIELD_TYPE_SIZE		0x00000040
#define DM_REPORT_FIELD_TYPE_PERCENT		0x00000080
#define DM_REPORT_FIELD_TYPE_STRING_LIST	0x00000100

#define DM_REPORT_FIELD_TYPE_ID_LEN 32
#define DM_REPORT_FIELD_TYPE_HEADING_LEN 32

struct dm_report;
struct dm_report_field_type {
	uint32_t type;		/* object type id */
	uint32_t flags;		/* DM_REPORT_FIELD_* */
	uint32_t offset;	/* byte offset in the object */
	int32_t width;		/* default width */
	/* string used to specify the field */
	const char id[DM_REPORT_FIELD_TYPE_ID_LEN];
	/* string printed in header */
	const char heading[DM_REPORT_FIELD_TYPE_HEADING_LEN];
	int (*report_fn)(struct dm_report *rh, struct dm_pool *mem,
			 struct dm_report_field *field, const void *data,
			 void *private_data);
	const char *desc;	/* description of the field */
};

/*
 * Per-field reserved value.
 */
struct dm_report_field_reserved_value {
	/* field_num is the position of the field in 'fields'
	   array passed to dm_report_init_with_selection */
	uint32_t field_num;
	/* the value is of the same type as the field
	   identified by field_num */
	const void *value;
};

/*
 * Reserved value is a 'value' that is used directly if any of the 'names' is hit.
 *
 * If type is any of DM_REPORT_FIELD_TYPE_*, the reserved value is recognized
 * for all fields of that type.
 *
 * If type is DM_REPORT_FIELD_TYPE_NONE, the reserved value is recognized
 * for the exact field specified - hence the type of the value is automatically
 * the same as the type of the field itself.
 *
 * The array of reserved values is used to initialize reporting with
 * selection enabled (see also dm_report_init_with_selection function).
 */
struct dm_report_reserved_value {
	const unsigned type;		/* DM_REPORT_FIELD_TYPE_* */
	const void *value;		/* reserved value:
						struct dm_report_field_reserved_value for DM_REPORT_FIELD_TYPE_NONE
						uint64_t for DM_REPORT_FIELD_TYPE_NUMBER
						uint64_t for DM_REPORT_FIELD_TYPE_SIZE (number of 512-byte sectors)
						uint64_t for DM_REPORT_FIELD_TYPE_PERCENT
						const char * for DM_REPORT_FIELD_TYPE_STRING */
	const char **names;		/* null-terminated array of names for this reserved value */
	const char *description;	/* description of the reserved value */
};

/*
 * dm_report_init output_flags
 */
#define DM_REPORT_OUTPUT_MASK			0x000000FF
#define DM_REPORT_OUTPUT_ALIGNED		0x00000001
#define DM_REPORT_OUTPUT_BUFFERED		0x00000002
#define DM_REPORT_OUTPUT_HEADINGS		0x00000004
#define DM_REPORT_OUTPUT_FIELD_NAME_PREFIX	0x00000008
#define DM_REPORT_OUTPUT_FIELD_UNQUOTED		0x00000010
#define DM_REPORT_OUTPUT_COLUMNS_AS_ROWS	0x00000020

struct dm_report *dm_report_init(uint32_t *report_types,
				 const struct dm_report_object_type *types,
				 const struct dm_report_field_type *fields,
				 const char *output_fields,
				 const char *output_separator,
				 uint32_t output_flags,
				 const char *sort_keys,
				 void *private_data);
struct dm_report *dm_report_init_with_selection(uint32_t *report_types,
						const struct dm_report_object_type *types,
						const struct dm_report_field_type *fields,
						const char *output_fields,
						const char *output_separator,
						uint32_t output_flags,
						const char *sort_keys,
						const char *selection,
						const struct dm_report_reserved_value reserved_values[],
						void *private_data);
int dm_report_object(struct dm_report *rh, void *object);
int dm_report_set_output_selection(struct dm_report *rh, uint32_t *report_types,
				   const char *selection);
int dm_report_output(struct dm_report *rh);
void dm_report_free(struct dm_report *rh);

/*
 * Prefix added to each field name with DM_REPORT_OUTPUT_FIELD_NAME_PREFIX
 */
int dm_report_set_output_field_name_prefix(struct dm_report *rh,
					   const char *report_prefix);

/*
 * Report functions are provided for simple data types.
 * They take care of allocating copies of the data.
 */
int dm_report_field_string(struct dm_report *rh, struct dm_report_field *field,
			   const char *const *data);
int dm_report_field_string_list(struct dm_report *rh, struct dm_report_field *field,
				const struct dm_list *data, const char *delimiter);
int dm_report_field_int32(struct dm_report *rh, struct dm_report_field *field,
			  const int32_t *data);
int dm_report_field_uint32(struct dm_report *rh, struct dm_report_field *field,
			   const uint32_t *data);
int dm_report_field_int(struct dm_report *rh, struct dm_report_field *field,
			const int *data);
int dm_report_field_uint64(struct dm_report *rh, struct dm_report_field *field,
			   const uint64_t *data);
int dm_report_field_percent(struct dm_report *rh, struct dm_report_field *field,
			    const dm_percent_t *data);

/*
 * For custom fields, allocate the data in 'mem' and use
 * dm_report_field_set_value().
 * 'sortvalue' may be NULL if it matches 'value'
 */
void dm_report_field_set_value(struct dm_report_field *field, const void *value,
			       const void *sortvalue);

/*************************
 * config file parse/print
 *************************/
typedef enum {
	DM_CFG_INT,
	DM_CFG_FLOAT,
	DM_CFG_STRING,
	DM_CFG_EMPTY_ARRAY
} dm_config_value_type_t;

struct dm_config_value {
	dm_config_value_type_t type;

	union {
		int64_t i;
		float f;
		double d;       	/* Unused. */
		const char *str;
	} v;

	struct dm_config_value *next;	/* For arrays */
};

struct dm_config_node {
	const char *key;
	struct dm_config_node *parent, *sib, *child;
	struct dm_config_value *v;
	int id;
};

struct dm_config_tree {
	struct dm_config_node *root;
	struct dm_config_tree *cascade;
	struct dm_pool *mem;
	void *custom;
};

struct dm_config_tree *dm_config_create(void);
struct dm_config_tree *dm_config_from_string(const char *config_settings);
int dm_config_parse(struct dm_config_tree *cft, const char *start, const char *end);

void *dm_config_get_custom(struct dm_config_tree *cft);
void dm_config_set_custom(struct dm_config_tree *cft, void *custom);

/*
 * When searching, first_cft is checked before second_cft.
 */
struct dm_config_tree *dm_config_insert_cascaded_tree(struct dm_config_tree *first_cft, struct dm_config_tree *second_cft);

/*
 * If there's a cascaded dm_config_tree, remove the top layer
 * and return the layer below.  Otherwise return NULL.
 */
struct dm_config_tree *dm_config_remove_cascaded_tree(struct dm_config_tree *cft);

void dm_config_destroy(struct dm_config_tree *cft);

/* Simple output line by line. */
typedef int (*dm_putline_fn)(const char *line, void *baton);
/* More advaced output with config node reference. */
typedef int (*dm_config_node_out_fn)(const struct dm_config_node *cn, const char *line, void *baton);

/*
 * Specification for advanced config node output.
 */
struct dm_config_node_out_spec {
	dm_config_node_out_fn prefix_fn; /* called before processing config node lines */
	dm_config_node_out_fn line_fn; /* called for each config node line */
	dm_config_node_out_fn suffix_fn; /* called after processing config node lines */
};

/* Write the node and any subsequent siblings it has. */
int dm_config_write_node(const struct dm_config_node *cn, dm_putline_fn putline, void *baton);
int dm_config_write_node_out(const struct dm_config_node *cn, const struct dm_config_node_out_spec *out_spec, void *baton);

/* Write given node only without subsequent siblings. */
int dm_config_write_one_node(const struct dm_config_node *cn, dm_putline_fn putline, void *baton);
int dm_config_write_one_node_out(const struct dm_config_node *cn, const struct dm_config_node_out_spec *out_spec, void *baton);

struct dm_config_node *dm_config_find_node(const struct dm_config_node *cn, const char *path);
int dm_config_has_node(const struct dm_config_node *cn, const char *path);
const char *dm_config_find_str(const struct dm_config_node *cn, const char *path, const char *fail);
const char *dm_config_find_str_allow_empty(const struct dm_config_node *cn, const char *path, const char *fail);
int dm_config_find_int(const struct dm_config_node *cn, const char *path, int fail);
int64_t dm_config_find_int64(const struct dm_config_node *cn, const char *path, int64_t fail);
float dm_config_find_float(const struct dm_config_node *cn, const char *path, float fail);

const struct dm_config_node *dm_config_tree_find_node(const struct dm_config_tree *cft, const char *path);
const char *dm_config_tree_find_str(const struct dm_config_tree *cft, const char *path, const char *fail);
const char *dm_config_tree_find_str_allow_empty(const struct dm_config_tree *cft, const char *path, const char *fail);
int dm_config_tree_find_int(const struct dm_config_tree *cft, const char *path, int fail);
int64_t dm_config_tree_find_int64(const struct dm_config_tree *cft, const char *path, int64_t fail);
float dm_config_tree_find_float(const struct dm_config_tree *cft, const char *path, float fail);
int dm_config_tree_find_bool(const struct dm_config_tree *cft, const char *path, int fail);

/*
 * Understands (0, ~0), (y, n), (yes, no), (on,
 * off), (true, false).
 */
int dm_config_find_bool(const struct dm_config_node *cn, const char *path, int fail);
int dm_config_value_is_bool(const struct dm_config_value *v);

int dm_config_get_uint32(const struct dm_config_node *cn, const char *path, uint32_t *result);
int dm_config_get_uint64(const struct dm_config_node *cn, const char *path, uint64_t *result);
int dm_config_get_str(const struct dm_config_node *cn, const char *path, const char **result);
int dm_config_get_list(const struct dm_config_node *cn, const char *path, const struct dm_config_value **result);
int dm_config_get_section(const struct dm_config_node *cn, const char *path, const struct dm_config_node **result);

unsigned dm_config_maybe_section(const char *str, unsigned len);

const char *dm_config_parent_name(const struct dm_config_node *n);

struct dm_config_node *dm_config_clone_node_with_mem(struct dm_pool *mem, const struct dm_config_node *node, int siblings);
struct dm_config_node *dm_config_create_node(struct dm_config_tree *cft, const char *key);
struct dm_config_value *dm_config_create_value(struct dm_config_tree *cft);
struct dm_config_node *dm_config_clone_node(struct dm_config_tree *cft, const struct dm_config_node *cn, int siblings);

struct dm_pool *dm_config_memory(struct dm_config_tree *cft);

/* Udev device directory. */
#define DM_UDEV_DEV_DIR "/dev/"

/* Cookie prefixes.
 *
 * The cookie value consists of a prefix (16 bits) and a base (16 bits).
 * We can use the prefix to store the flags. These flags are sent to
 * kernel within given dm task. When returned back to userspace in
 * DM_COOKIE udev environment variable, we can control several aspects
 * of udev rules we use by decoding the cookie prefix. When doing the
 * notification, we replace the cookie prefix with DM_COOKIE_MAGIC,
 * so we notify the right semaphore.
 *
 * It is still possible to use cookies for passing the flags to udev
 * rules even when udev_sync is disabled. The base part of the cookie
 * will be zero (there's no notification semaphore) and prefix will be
 * set then. However, having udev_sync enabled is highly recommended.
 */
#define DM_COOKIE_MAGIC 0x0D4D
#define DM_UDEV_FLAGS_MASK 0xFFFF0000
#define DM_UDEV_FLAGS_SHIFT 16

/*
 * DM_UDEV_DISABLE_DM_RULES_FLAG is set in case we need to disable
 * basic device-mapper udev rules that create symlinks in /dev/<DM_DIR>
 * directory. However, we can't reliably prevent creating default
 * nodes by udev (commonly /dev/dm-X, where X is a number).
 */
#define DM_UDEV_DISABLE_DM_RULES_FLAG 0x0001
/*
 * DM_UDEV_DISABLE_SUBSYTEM_RULES_FLAG is set in case we need to disable
 * subsystem udev rules, but still we need the general DM udev rules to
 * be applied (to create the nodes and symlinks under /dev and /dev/disk).
 */
#define DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG 0x0002
/*
 * DM_UDEV_DISABLE_DISK_RULES_FLAG is set in case we need to disable
 * general DM rules that set symlinks in /dev/disk directory.
 */
#define DM_UDEV_DISABLE_DISK_RULES_FLAG 0x0004
/*
 * DM_UDEV_DISABLE_OTHER_RULES_FLAG is set in case we need to disable
 * all the other rules that are not general device-mapper nor subsystem
 * related (the rules belong to other software or packages). All foreign
 * rules should check this flag directly and they should ignore further
 * rule processing for such event.
 */
#define DM_UDEV_DISABLE_OTHER_RULES_FLAG 0x0008
/*
 * DM_UDEV_LOW_PRIORITY_FLAG is set in case we need to instruct the
 * udev rules to give low priority to the device that is currently
 * processed. For example, this provides a way to select which symlinks
 * could be overwritten by high priority ones if their names are equal.
 * Common situation is a name based on FS UUID while using origin and
 * snapshot devices.
 */
#define DM_UDEV_LOW_PRIORITY_FLAG 0x0010
/*
 * DM_UDEV_DISABLE_LIBRARY_FALLBACK is set in case we need to disable
 * libdevmapper's node management. We will rely on udev completely
 * and there will be no fallback action provided by libdevmapper if
 * udev does something improperly.
 */
#define DM_UDEV_DISABLE_LIBRARY_FALLBACK 0x0020
/*
 * DM_UDEV_PRIMARY_SOURCE_FLAG is automatically appended by
 * libdevmapper for all ioctls generating udev uevents. Once used in
 * udev rules, we know if this is a real "primary sourced" event or not.
 * We need to distinguish real events originated in libdevmapper from
 * any spurious events to gather all missing information (e.g. events
 * generated as a result of "udevadm trigger" command or as a result
 * of the "watch" udev rule).
 */
#define DM_UDEV_PRIMARY_SOURCE_FLAG 0x0040

/*
 * Udev flags reserved for use by any device-mapper subsystem.
 */
#define DM_SUBSYSTEM_UDEV_FLAG0 0x0100
#define DM_SUBSYSTEM_UDEV_FLAG1 0x0200
#define DM_SUBSYSTEM_UDEV_FLAG2 0x0400
#define DM_SUBSYSTEM_UDEV_FLAG3 0x0800
#define DM_SUBSYSTEM_UDEV_FLAG4 0x1000
#define DM_SUBSYSTEM_UDEV_FLAG5 0x2000
#define DM_SUBSYSTEM_UDEV_FLAG6 0x4000
#define DM_SUBSYSTEM_UDEV_FLAG7 0x8000

int dm_cookie_supported(void);

/*
 * Udev synchronisation functions.
 */
void dm_udev_set_sync_support(int sync_with_udev);
int dm_udev_get_sync_support(void);
void dm_udev_set_checking(int checking);
int dm_udev_get_checking(void);

/*
 * Default value to get new auto generated cookie created
 */
#define DM_COOKIE_AUTO_CREATE 0
int dm_udev_create_cookie(uint32_t *cookie);
int dm_udev_complete(uint32_t cookie);
int dm_udev_wait(uint32_t cookie);

#define DM_DEV_DIR_UMASK 0022
#define DM_CONTROL_NODE_UMASK 0177

#ifdef __cplusplus
}
#endif
#endif				/* LIB_DEVICE_MAPPER_H */
