/**
 * fs_misc.h
 * This file contains miscellaneous defines and declarations associated with filesystem.
 * The code is added by zcr, and the file is added by xw. 18/6/17
 */

#ifndef	FS_MISC_H
#define	FS_MISC_H

#include "fat32.h"

/**
 * @struct dev_drv_map fs.h "include/sys/fs.h"
 * @brief  The Device_nr.\ - Driver_nr.\ MAP.
 */
struct dev_drv_map {
	int driver_nr; /**< The proc nr.\ of the device driver. */
};

/**
 * @def   MAGIC_V1
 * @brief Magic number of FS v1.0
 */
#define	MAGIC_V1	0x111

/**
 * @struct super_block fs.h "include/fs.h"
 * @brief  The 2nd sector of the FS
 *
 * Remember to change SUPER_BLOCK_SIZE if the members are changed.
 */
struct super_block {
	u32	magic;		  /**< Magic number */
	u32	nr_inodes;	  /**< How many inodes */
	u32	nr_sects;	  /**< How many sectors */
	u32	nr_imap_sects;	  /**< How many inode-map sectors */
	u32	nr_smap_sects;	  /**< How many sector-map sectors */
	u32	n_1st_sect;	  /**< Number of the 1st data sector */
	u32	nr_inode_sects;   /**< How many inode sectors */
	u32	root_inode;       /**< Inode nr of root directory */
	u32	inode_size;       /**< INODE_SIZE */
	u32	inode_isize_off;  /**< Offset of `struct inode::i_size' */
	u32	inode_start_off;  /**< Offset of `struct inode::i_start_sect' */
	u32	dir_ent_size;     /**< DIR_ENTRY_SIZE */
	u32	dir_ent_inode_off;/**< Offset of `struct dir_entry::inode_nr' */
	u32	dir_ent_fname_off;/**< Offset of `struct dir_entry::name' */

	/*
	 * the following item(s) are only present in memory
	 */
	int	sb_dev; 	/**< the super block's home device */
	int fs_type;	//added by mingxuan 2020-10-30
};

/**
 * @def   SUPER_BLOCK_SIZE
 * @brief The size of super block \b in \b the \b device.
 *
 * Note that this is the size of the struct in the device, \b NOT in memory.
 * The size in memory is larger because of some more members.
 */
//#define	SUPER_BLOCK_SIZE	56
#define	SUPER_BLOCK_SIZE	64		//modified by mingxuan 2020-10-30

/**
 * @struct inode
 * @brief  i-node
 *
 * The \c start_sect and\c nr_sects locate the file in the device,
 * and the size show how many bytes is used.
 * If <tt> size < (nr_sects * SECTOR_SIZE) </tt>, the rest bytes
 * are wasted and reserved for later writing.
 *
 * \b NOTE: Remember to change INODE_SIZE if the members are changed
 */
struct inode {
	u32	i_mode;		/**< Accsess mode */
	u32	i_size;		/**< File size */
	u32	i_start_sect;	/**< The first sector of the data */
	u32	i_nr_sects;	/**< How many sectors the file occupies */
	u8	_unused[16];	/**< Stuff for alignment */

	/* the following items are only present in memory */
	int	i_dev;
	int	i_cnt;		/**< How many procs share this inode  */
	int	i_num;		/**< inode nr.  */
};

/**
 * @def   INODE_SIZE
 * @brief The size of i-node stored \b in \b the \b device.
 *
 * Note that this is the size of the struct in the device, \b NOT in memory.
 * The size in memory is larger because of some more members.
 */
#define	INODE_SIZE	32

/**
 * @struct dir_entry
 * @brief  Directory Entry
 */
struct dir_entry {
	int	inode_nr;		/**< inode nr. */
	char name[MAX_FILENAME_LEN];	/**< Filename */
};

/**
 * @def   DIR_ENTRY_SIZE
 * @brief The size of directory entry in the device.
 *
 * It is as same as the size in memory.
 */
#define	DIR_ENTRY_SIZE	sizeof(struct dir_entry)

/**
 * @struct file_desc
 * @brief  File Descriptor
 */

//added by mingxuan 2019-5-17
union ptr_node{
	struct inode*	fd_inode;	/**< Ptr to the i-node */
	PFile 	fd_file;	//指向fat32的file结构体
};

struct file_desc {
	int		fd_mode;	/**< R or W */
	int		fd_pos;		/**< Current position for R/W. */
	//struct inode*	fd_inode;	/**< Ptr to the i-node */	//deleted by mingxuan 2019-5-17
	
	//added by mingxuan 2019-5-17
	union 	ptr_node fd_node;
	int 	flag;	//用于标志描述符是否被使用
	int 	dev_index;
};


/**
 * Since all invocations of `rw_sector()' in FS look similar (most of the
 * params are the same), we use this macro to make code more readable.
 */
#define RD_SECT(dev,sect_nr,fsbuf) rw_sector(DEV_READ, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* read one sector */ \
				       proc2pid(p_proc_current),/*TASK_A*/			\
				       fsbuf);

#define WR_SECT(dev,sect_nr,fsbuf) rw_sector(DEV_WRITE, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* write one sector */ \
				       proc2pid(p_proc_current),				\
				       fsbuf);

//modified by mingxuan 2020-10-27
#define RD_SECT_FAT(dev, buf, sect_nr) rw_sector_fat(DEV_READ, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* read one sector */ \
				       proc2pid(p_proc_current),/*TASK_A*/			\
				       buf);

//modified by mingxuan 2020-10-27
#define WR_SECT_FAT(dev, buf, sect_nr) rw_sector_fat(DEV_WRITE, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* write one sector */ \
				       proc2pid(p_proc_current),				\
				       buf);

//added by xw, 18/8/27
#define RD_SECT_SCHED(dev,sect_nr,fsbuf) rw_sector_sched(DEV_READ, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* read one sector */ \
				       proc2pid(p_proc_current),/*TASK_A*/			\
				       fsbuf);

#define WR_SECT_SCHED(dev,sect_nr,fsbuf) rw_sector_sched(DEV_WRITE, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* write one sector */ \
				       proc2pid(p_proc_current),				\
				       fsbuf);

//modified by mingxuan 2020-10-27
#define RD_SECT_SCHED_FAT(dev, buf, sect_nr) rw_sector_sched_fat(DEV_READ, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* read one sector */ \
				       proc2pid(p_proc_current),/*TASK_A*/			\
				       buf);

//modified by mingxuan 2020-10-27
#define WR_SECT_SCHED_FAT(dev, buf, sect_nr) rw_sector_sched_fat(DEV_WRITE, \
				       dev,				\
				       (sect_nr) * SECTOR_SIZE,		\
				       SECTOR_SIZE, /* write one sector */ \
				       proc2pid(p_proc_current),				\
				       buf);
//~xw
#endif /* FS_MISC_H */