// ext2.h
// Author: Josh Holtrop
// Date: 08/22/04
// Modified: 12/24/04

#ifndef __HOS_EXT2_H__
#define __HOS_EXT2_H__ __HOS_EXT2_H__

#include "hos_defines.h"
#include "fs/devices.h"
#include "fs/vfs.h"

#define EXT2_MAGIC 0xEF53
#define EXT2_NAME_LEN 255

#define EXT2_I_MODE_ATTR_MASK	0x0FFF
#define EXT2_I_MODE_OX		0x0001
#define EXT2_I_MODE_OW		0x0002
#define EXT2_I_MODE_OR		0x0004
#define EXT2_I_MODE_GX		0x0008
#define EXT2_I_MODE_GW		0x0010
#define EXT2_I_MODE_GR		0x0020
#define EXT2_I_MODE_UX		0x0040
#define EXT2_I_MODE_UW		0x0080
#define EXT2_I_MODE_UR		0x0100
#define EXT2_I_MODE_STICKY	0x0200
#define EXT2_I_MODE_SGID	0x0400
#define EXT2_I_MODE_SUID	0x0800

#define EXT2_I_MODE_TYPE_MASK	0xF000
#define EXT2_I_MODE_FIFO	0x1000
#define EXT2_I_MODE_CHAR	0x2000
#define EXT2_I_MODE_DIR		0x4000
#define EXT2_I_MODE_BLOCK	0x6000
#define EXT2_I_MODE_FILE	0x8000
#define EXT2_I_MODE_SYM		0xA000
#define EXT2_I_MODE_SOCK	0xC000

#define EXT2_I_FLAGS_SEC_DEL	0x01
#define EXT2_I_FLAGS_UNDELETE	0x02
#define EXT2_I_FLAGS_COMPRESS	0x04
#define EXT2_I_FLAGS_SYNC	0x08
#define EXT2_I_FLAGS_IMMUTABLE	0x10
#define EXT2_I_FLAGS_APPEND	0x20
#define EXT2_I_FLAGS_NODUMP	0x40

#define EXT2_INODE_BAD_BLOCKS	1
#define EXT2_INODE_ROOT		2
#define EXT2_INODE_ACL_INDEX	3
#define EXT2_INODE_ACL_DATA	4
#define EXT2_INODE_BOOT_LOADER	5
#define EXT2_INODE_UNDELETE_DIR	6
#define EXT2_INODE_AVAIL	11

#define EXT2_FT_UNKNOWN	0
#define EXT2_FT_FILE	1
#define EXT2_FT_DIR	2
#define EXT2_FT_CHAR	3
#define EXT2_FT_BLOCK	4
#define EXT2_FT_FIFO	5
#define EXT2_FT_SOCK	6
#define EXT2_FT_SYMLINK	7
#define EXT2_FT_MAX	8

typedef struct
{
	u32_t	s_inodes_count;		/* Inodes count */
	u32_t	s_blocks_count;		/* Blocks count */
	u32_t	s_r_blocks_count;	/* Reserved blocks count */
	u32_t	s_free_blocks_count;	/* Free blocks count */
	u32_t	s_free_inodes_count;	/* Free inodes count */
	u32_t	s_first_data_block;	/* First Data Block */
	u32_t	s_log_block_size;	/* Block size: 0->1024, 1->2048, 2->4096 */
	int	s_log_frag_size;	/* Fragment size */
	u32_t	s_blocks_per_group;	/* # Blocks per group */
	u32_t	s_frags_per_group;	/* # Fragments per group */
	u32_t	s_inodes_per_group;	/* # Inodes per group */
	u32_t	s_mtime;			/* Mount time */
	u32_t	s_wtime;			/* Write time */
	u16_t	s_mnt_count;		/* Mount count */
	short	s_max_mnt_count;		/* Maximal mount count */
	u16_t	s_magic;			/* Magic signature */
	u16_t	s_state;		/* File system state */
	u16_t	s_errors;		/* Behaviour when detecting errors */
	u16_t	s_minor_rev_level;	/* minor revision level */
	u32_t	s_lastcheck;		/* time of last check */
	u32_t	s_checkinterval;	/* max. time between checks */
	u32_t	s_creator_os;		/* OS */
	u32_t	s_rev_level;		/* Revision level */
	u16_t	s_def_resuid;		/* Default uid for reserved blocks */
	u16_t	s_def_resgid;		/* Default gid for reserved blocks */

	u32_t	s_reserved[235];
} ext2_super_block_t;

typedef struct
{
	u32_t	bg_block_bitmap;	// Blocks bitmap block
	u32_t	bg_inode_bitmap;	// Inode bitmap block
	u32_t	bg_inode_table;		// Inode table block
	u16_t	bg_free_blocks_count;	// Free blocks count
	u16_t	bg_free_inodes_count;	// Free Inodes count
	u16_t	bg_used_dirs_count;	// Directories count
	u16_t	bg_pad1;
	u32_t	bg_reserved[3];
} ext2_group_desc_t;

typedef struct
{
	u16_t	i_mode;			// File mode
	u16_t	i_uid;			// Owner UID
	u32_t	i_size;			// Size in bytes
	u32_t	i_atime;		// Access time
	u32_t	i_ctime;		// Creation time
	u32_t	i_mtime;		// Modification time
	u32_t	i_dtime;		// Deletion time
	u16_t	i_gid;			// Group ID
	u16_t	i_links_count;		// Links count
	u32_t	i_blocks;		// Blocks count
	u32_t	i_flags;		// File flags
	u32_t	i_reserved1;
	u32_t	i_block[15];		// Pointers to blocks (12 direct, single, double, triple indirect)
	u32_t	i_version;		// File version (for NFS)
	u32_t	i_file_acl;		// File ACL
	u32_t	i_dir_acl;		// Directory ACL
	u32_t	i_faddr;		// Fragment address
	u8_t	i_frag;			// Fragment number
	u8_t	i_fsize;		// Fragment size
	u16_t	i_pad1;
	u32_t	i_reserved2[2];
} ext2_inode_t;

typedef struct
{
	u32_t	inode;			// inode number
	u16_t	length;			// directory entry length
	u8_t	name_length;		// name length
	u8_t	file_type;		// File type
	char	name[EXT2_NAME_LEN];
} ext2_dir_entry_t;

typedef struct
{
	ext2_inode_t	inode;
	u32_t	block;
	u32_t	*block_pointers;
	u32_t	block_pointers_start;
} ext2_open_inode_t;

typedef struct
{
	ext2_open_inode_t	*open_inode;
	u32_t	position;
} ext2_open_dir_t;

typedef struct
{
	ext2_open_inode_t	*open_inode;
	u32_t	position;
	u32_t	buffer_start;
	u32_t	buffer_bytes;
	u8_t	*buffer;
} ext2__open_file_t;

typedef struct
{
	ext2_open_inode_t	*open_inode;
	u32_t	block;
} ext2__open_block_file_t;

static inline u32_t	ext2_diskToFSBlock(u32_t block, ext2_super_block_t *super)
{
	// convert # of disk blocks to # of filesystem blocks
	return block >> (super->s_log_block_size + 1);
}

static inline u32_t	ext2_FSToDiskBlock(u32_t block, ext2_super_block_t *super)
{
	// convert # of filesystem blocks to # of disk blocks
	return block << (super->s_log_block_size + 1);
}


int	ext2_init(int fsID);
int	ext2_read_inode(vfs_mount_t *mount, u32_t inode, ext2_inode_t *dat);
int	ext2_write_inode(vfs_mount_t *mount, u32_t inode, ext2_inode_t *dat);
ext2_group_desc_t	ext2_get_group_desc(vfs_mount_t *mount, u32_t group);
void	ext2_write_group_desc(vfs_mount_t *mount, u32_t group_num, ext2_group_desc_t *gd);
ext2_open_inode_t *ext2_open_inode(vfs_mount_t *mount, u32_t inode_number);
int	ext2_close_inode(vfs_mount_t *mount, ext2_open_inode_t *open_inode);
int	ext2_read_inode_block(vfs_mount_t *mount, ext2_open_inode_t *open_inode, void *block);
u32_t	ext2_block_number(vfs_mount_t *mount, ext2_open_inode_t *open_inode);
int	ext2_inode_seek(vfs_mount_t *mount, ext2_open_inode_t *open_inode, u32_t block_number);

int	ext2_inode_status(vfs_mount_t *mount, u32_t inode_number);
int	ext2_block_status(vfs_mount_t *mount, u32_t block_number);

u32_t	ext2_alloc_inode(vfs_mount_t *mount);
int	ext2_free_inode(vfs_mount_t *mount, u32_t inode_number);
u32_t	ext2_alloc_block(vfs_mount_t *mount);
int	ext2_free_block(vfs_mount_t *mount, u32_t block_number);

u32_t	ext2_reserve_node(vfs_mount_t *mount, u32_t bitmap_block_num, u32_t bitmap_size);
int	ext2_free_node(vfs_mount_t *mount, u32_t bitmap_block_num, u32_t node_number);
int	ext2_num_block_groups(ext2_super_block_t *super);
void	ext2_write_super(vfs_mount_t *mount);

int	ext2_resize_inode(vfs_mount_t *mount, u32_t inode_number, u32_t new_size);

ext2_open_dir_t *ext2_open_dir(vfs_mount_t *mount, u32_t inode_number);
int	ext2_dir_read_entry(vfs_mount_t *mount, ext2_open_dir_t *open_dir, ext2_dir_entry_t *dentry);
int	ext2_close_dir(vfs_mount_t *mount, ext2_open_dir_t *open_dir);
int	ext2_dir_lookup(vfs_mount_t *mount, u32_t dir_inode, char *fileName, ext2_dir_entry_t *direntry);


void	*ext2_mount_super(major_t major, minor_t minor);
int	ext2_umount_super(vfs_mount_t *mount);
int	ext2_stat(vfs_mount_t *mount, u32_t inode_number, vfs_stat_t *stat);
u32_t	ext2__get_root_dir_inode(vfs_mount_t *mount);
int	ext2__link_deref(vfs_mount_t *mount, u32_t link_inode, char *link);
int	ext2__free_inodes(vfs_mount_t *mount);
int	ext2__total_inodes(vfs_mount_t *mount);
int	ext2__free_blocks(vfs_mount_t *mount);
int	ext2__total_blocks(vfs_mount_t *mount);


int	ext2__open_dir(vfs_mount_t *mount, u32_t inode_number, vfs_open_file_t *dir);
int	ext2__read_dir(vfs_mount_t *mount, vfs_open_file_t *dir, vfs_dir_entry_t *dentry);
int	ext2__close_dir(vfs_mount_t *mount, vfs_open_file_t *dir);

int	ext2__open_file(vfs_mount_t *mount, u32_t inode_number, vfs_open_file_t *open_file);
int	ext2__read_file(vfs_mount_t *mount, vfs_open_file_t *open_file);
int	ext2__close_file(vfs_mount_t *mount, vfs_open_file_t *open_file);

int	ext2__open_block_file(vfs_mount_t *mount, u32_t inode_number, vfs_open_file_t *open_file);
int	ext2__read_block_file(vfs_mount_t *mount, vfs_open_file_t *open_file, void *buffer);
int	ext2__block_file_seek(vfs_mount_t *mount, vfs_open_file_t *open_file, u32_t block_number);
int	ext2__close_block_file(vfs_mount_t *mount, vfs_open_file_t *open_file);

#endif