// ext2.h
// ext2 filesystem driver for HOS
// Author: Josh Holtrop
// Date: 05/10/05
// Modified: 05/23/05

#ifndef __HOS_EXT2_H__
#define __HOS_EXT2_H__ __HOS_EXT2_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

/* ext2 standard inode numbers */
#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

/* The directory entry file type field values */
#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

#include "fs/vfs.h"

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;		// Disk Blocks count (512)
	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 (used???)
	char	name[EXT2_NAME_LEN];
} ext2_dir_entry_t;

#ifdef _HOS_CPP_

int	ext2_init();
FileSystem *ext2__mount_func(device_t dev);

class Ext2fs : public FileSystem
{
protected:
/* my data members */
	device_t	myDevice;
	int		mySuperDirty;
	ext2_super_block_t mySuper;
	u32_t		myNumGroups;
	u32_t		myGroupDescriptorBlocks;
	u32_t		myInodeTableBlocks;
	u32_t		myGroupDescriptorsPerBlock;
	u32_t		myInodesPerBlock;

/* my functions */
	int	readGroupDescriptor(u32_t group, ext2_group_desc_t *buf);
	int	writeGroupDescriptor(u32_t group, ext2_group_desc_t *buf);
	int	inodeStatus(u32_t inum);
	int	blockStatus(u32_t bnum);
	u32_t	allocFromBitmap(u32_t blockNum, u32_t max);
	void	freeFromBitmap(u32_t blockNum, u32_t node);

public:
	Ext2fs(ext2_super_block_t *super, device_t dev);
	~Ext2fs();
	u32_t	totalBlocks();
	u32_t	freeBlocks();
	u32_t	totalInodes();
	u32_t	freeInodes();
	u32_t	getRootInodeNumber();
	OpenDirectory *openDirectory(u32_t inum, int mode);
	OpenFile *openFile(u32_t inum, int mode);
	int	stat(u32_t inum, vfs_stat_t *buf);
	int	readBlock(u32_t blockNum, void *buf);
	int	writeBlock(u32_t blockNum, void *buf);
	int	link_deref(u32_t inum, char *buf);
	int	readInode(u32_t inum, ext2_inode_t *buf);
	int	writeInode(u32_t inum, ext2_inode_t *buf);
	u32_t	allocInode();
	u32_t	allocBlock();
	int	freeInode(u32_t inum);
	int	freeBlock(u32_t bnum);
	void	unlink(u32_t inum);
	int	attemptRemoveDir(u32_t inum);
	void	truncateInode(u32_t inum);
	int	initializeDirectory(u32_t inum, u32_t parent);

	/* inlined functions */
	inline u32_t numGroups() { return myNumGroups; }
	inline u32_t groupDescriptorBlocks() { return myGroupDescriptorBlocks; }
	inline u32_t inodeTableBlocks() { return myInodeTableBlocks; }
	inline ext2_super_block_t *getSuper() { return &mySuper; }
};

#endif

#endif