/*
 * nilfs.h - NILFS header file.
 *
 * Copyright (C) 2007-2012 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * Written by Koji Sato.
 *
 * Maintained by Ryusuke Konishi <konishi.ryusuke@gmail.com> from 2008.
 */

#ifndef NILFS_H
#define NILFS_H

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <sys/ioctl.h>
#include <semaphore.h>
#include <linux/types.h>
#include <linux/nilfs2_ondisk.h>
#include <linux/nilfs2_api.h>

typedef __u64 nilfs_cno_t;

#define NILFS_FSTYPE	"nilfs2"

#define NILFS_CNO_MIN	((nilfs_cno_t)1)
#define NILFS_CNO_MAX	(~(nilfs_cno_t)0)

#define NILFS_SB_LABEL			0x0001
#define NILFS_SB_UUID			0x0002
#define NILFS_SB_FEATURES		0x0004
#define NILFS_SB_COMMIT_INTERVAL	0x4000
#define NILFS_SB_BLOCK_MAX		0x8000

/**
 * struct nilfs - nilfs object
 * @n_sb: superblock
 * @n_dev: device file
 * @n_ioc: ioctl file
 * @n_devfd: file descriptor of device file
 * @n_iocfd: file descriptor of ioctl file
 * @n_opts: options
 * @n_mincno: the minimum of valid checkpoint numbers
 * @n_sems: array of semaphores
 *     sems[0] protects garbage collection process
 */
struct nilfs {
	struct nilfs_super_block *n_sb;
	char *n_dev;
	/* char *n_mnt; */
	char *n_ioc;
	int n_devfd;
	int n_iocfd;
	int n_opts;
	nilfs_cno_t n_mincno;
	sem_t *n_sems[1];
};

#define NILFS_OPEN_RAW		0x0001	/* Open RAW device */
#define NILFS_OPEN_RDONLY	0x0002	/* Open NILFS API in read only mode */
#define NILFS_OPEN_WRONLY	0x0004	/* Open NILFS API in write only mode */
#define NILFS_OPEN_RDWR		0x0008	/* Open NILFS API in read/write mode */
#define NILFS_OPEN_GCLK		0x1000	/* Open GC lock primitive */

#define NILFS_OPT_MMAP		0x01
#define NILFS_OPT_SET_SUINFO	0x02


struct nilfs *nilfs_open(const char *, const char *, int);
void nilfs_close(struct nilfs *);

const char *nilfs_get_dev(const struct nilfs *);

void nilfs_opt_clear_mmap(struct nilfs *);
int nilfs_opt_set_mmap(struct nilfs *);
int nilfs_opt_test_mmap(struct nilfs *);

void nilfs_opt_clear_set_suinfo(struct nilfs *);
int nilfs_opt_set_set_suinfo(struct nilfs *);
int nilfs_opt_test_set_suinfo(struct nilfs *);

nilfs_cno_t nilfs_get_oldest_cno(struct nilfs *);

struct nilfs_super_block *nilfs_get_sb(struct nilfs *);


#define NILFS_LOCK_FNS(name, index)					\
static inline int nilfs_lock_##name(struct nilfs *nilfs)		\
{									\
	return sem_wait(nilfs->n_sems[index]);				\
}									\
static inline int nilfs_trylock_##name(struct nilfs *nilfs)		\
{									\
	return sem_trywait(nilfs->n_sems[index]);			\
}									\
static inline int nilfs_unlock_##name(struct nilfs *nilfs)		\
{									\
	return sem_post(nilfs->n_sems[index]);				\
}

NILFS_LOCK_FNS(cleaner, 0)

/**
 * nilfs_get_root_path - get the path name string of the mount point
 * @nilfs: nilfs object
 *
 * Return: The absolute path name of the mount point directory, or %NULL if
 * unavailable.
 */
static inline const char *nilfs_get_root_path(const struct nilfs *nilfs)
{
	return nilfs->n_ioc;
}

/**
 * nilfs_get_root_fd - get the file descriptor of the mount point directory
 *                     (file system root directory)
 * @nilfs: nilfs object
 *
 * Return: The file descriptor of the mount point directory, or -1 if not
 * available.
 */
static inline int nilfs_get_root_fd(const struct nilfs *nilfs)
{
	return nilfs->n_iocfd;
}

/**
 * struct nilfs_psegment - partial segment iterator
 * @p_segnum: segment number
 * @p_blocknr: block number of partial segment
 * @p_segblocknr: block number of segment
 * @p_nblocks: number of blocks in segment
 * @p_maxblocks: maximum number of blocks in segment
 * @p_blksize: block size
 * @p_seed: CRC seed
 */
struct nilfs_psegment {
	struct nilfs_segment_summary *p_segsum;
	__u64 p_blocknr;

	__u64 p_segblocknr;
	size_t p_nblocks;
	size_t p_maxblocks;
	size_t p_blksize;
	__u32 p_seed;
};

/**
 * struct nilfs_file - file iterator
 * @f_finfo: file information
 * @f_blocknr: block number
 * @f_offset: byte offset from the beginning of segment
 * @f_index: index
 * @f_psegment: partial segment
 */
struct nilfs_file {
	struct nilfs_finfo *f_finfo;
	__u64 f_blocknr;

	unsigned long f_offset;
	int f_index;
	const struct nilfs_psegment *f_psegment;
};

/**
 * struct nilfs_block - block iterator
 * @b_binfo: block information
 * @b_blocknr: block number
 * @b_offset: byte offset from the beginning of segment
 * @b_index: index
 * @b_dsize: size of data block information
 * @b_nsize: size of node block information
 * @b_file: file
 */
struct nilfs_block {
	void *b_binfo;
	__u64 b_blocknr;

	unsigned long b_offset;
	int b_index;
	size_t b_dsize;
	size_t b_nsize;
	const struct nilfs_file *b_file;
};

/* virtual block number and block offset */
#define NILFS_BINFO_DATA_SIZE		(sizeof(__le64) + sizeof(__le64))
/* virtual block number */
#define NILFS_BINFO_NODE_SIZE		sizeof(__le64)
/* block offset */
#define NILFS_BINFO_DAT_DATA_SIZE	sizeof(__le64)
/* block offset and level */
#define NILFS_BINFO_DAT_NODE_SIZE	(sizeof(__le64) + sizeof(__le64))


/* partial segment iterator */
void nilfs_psegment_init(struct nilfs_psegment *, __u64,
			 void *, size_t, const struct nilfs *);
int nilfs_psegment_is_end(const struct nilfs_psegment *);
void nilfs_psegment_next(struct nilfs_psegment *);

#define nilfs_psegment_for_each(pseg, segnum, seg, nblocks, nilfs)	\
	for (nilfs_psegment_init(pseg, segnum, seg, nblocks, nilfs);	\
	     !nilfs_psegment_is_end(pseg);				\
	     nilfs_psegment_next(pseg))

/* file iterator */
void nilfs_file_init(struct nilfs_file *, const struct nilfs_psegment *);
int nilfs_file_is_end(const struct nilfs_file *);
void nilfs_file_next(struct nilfs_file *);

static inline int nilfs_file_is_super(const struct nilfs_file *file)
{
	__u64 ino;

	ino = __le64_to_cpu(file->f_finfo->fi_ino);
	return ino == NILFS_DAT_INO;
}

#define nilfs_file_for_each(file, pseg)		\
	for (nilfs_file_init(file, pseg);	\
	     !nilfs_file_is_end(file);		\
	     nilfs_file_next(file))

/* block iterator */
void nilfs_block_init(struct nilfs_block *, const struct nilfs_file *);
int nilfs_block_is_end(const struct nilfs_block *);
void nilfs_block_next(struct nilfs_block *);

static inline int nilfs_block_is_data(const struct nilfs_block *blk)
{
	return blk->b_index < __le32_to_cpu(blk->b_file->f_finfo->fi_ndatablk);
}

static inline int nilfs_block_is_node(const struct nilfs_block *blk)
{
	return blk->b_index >= __le32_to_cpu(blk->b_file->f_finfo->fi_ndatablk);
}

#define nilfs_block_for_each(blk, file)		\
	for (nilfs_block_init(blk, file);	\
	     !nilfs_block_is_end(blk);		\
	     nilfs_block_next(blk))

#define NILFS_SB_BLOCK_SIZE_SHIFT	10

struct nilfs_super_block *nilfs_sb_read(int devfd);
int nilfs_sb_write(int devfd, struct nilfs_super_block *sbp, int mask);

int nilfs_read_sb(struct nilfs *);

ssize_t nilfs_get_segment(struct nilfs *, unsigned long, void **);
int nilfs_put_segment(struct nilfs *, void *);
size_t nilfs_get_block_size(struct nilfs *);
__u64 nilfs_get_segment_seqnum(const struct nilfs *, void *, __u64);
__u64 nilfs_get_reserved_segments(const struct nilfs *nilfs);

int nilfs_change_cpmode(struct nilfs *, nilfs_cno_t, int);
ssize_t nilfs_get_cpinfo(struct nilfs *, nilfs_cno_t, int,
			 struct nilfs_cpinfo *, size_t);
int nilfs_delete_checkpoint(struct nilfs *, nilfs_cno_t);
int nilfs_get_cpstat(const struct nilfs *, struct nilfs_cpstat *);
ssize_t nilfs_get_suinfo(const struct nilfs *, __u64, struct nilfs_suinfo *,
			 size_t);
int nilfs_set_suinfo(const struct nilfs *, struct nilfs_suinfo_update *,
		     size_t);
int nilfs_get_sustat(const struct nilfs *, struct nilfs_sustat *);
ssize_t nilfs_get_vinfo(const struct nilfs *, struct nilfs_vinfo *, size_t);
ssize_t nilfs_get_bdescs(const struct nilfs *, struct nilfs_bdesc *, size_t);
int nilfs_clean_segments(struct nilfs *, struct nilfs_vdesc *, size_t,
			 struct nilfs_period *, size_t, __u64 *, size_t,
			 struct nilfs_bdesc *, size_t, __u64 *, size_t);
int nilfs_sync(const struct nilfs *, nilfs_cno_t *);
int nilfs_resize(struct nilfs *nilfs, off_t size);
int nilfs_set_alloc_range(struct nilfs *nilfs, off_t start, off_t end);

static inline __u64 nilfs_get_nsegments(const struct nilfs *nilfs)
{
	return __le64_to_cpu(nilfs->n_sb->s_nsegments);
}

static inline __u32 nilfs_get_blocks_per_segment(const struct nilfs *nilfs)
{
	return __le32_to_cpu(nilfs->n_sb->s_blocks_per_segment);
}

#endif	/* NILFS_H */