fs.h

JFFS的源代码

#ifndef _FS_H
#define _FS_H

#include "../jffs/jffstypes.h"

#define NR_OPEN 16

#define BLOCK_SIZE 1024
#define BLOCK_SIZE_BITS 10

#define FMODE_READ 1
#define FMODE_WRITE 2

#ifndef NULL
#define NULL ((void *) 0)
#endif

#define NIL_FILP	((struct file *)0)
#define SEL_IN		1
#define SEL_OUT		2
#define SEL_EX		4

/*
 * These are the fs-independent mount-flags: up to 16 flags are supported
 */
#define MS_RDONLY	 1	/* Mount read-only */
#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
#define MS_NODEV	 4	/* Disallow access to device special files */
#define MS_NOEXEC	 8	/* Disallow program execution */
#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
#define S_WRITE		128	/* Write on file/directory/symlink */
#define S_APPEND	256	/* Append-only file */
#define S_IMMUTABLE	512	/* Immutable file */
#define MS_NOATIME	1024	/* Do not update access times. */
#define S_BAD_INODE	2048	/* Marker for unreadable inodes */
#define S_ZERO_WR	4096	/* Device accepts 0 length writes */

/*
 * Flags that can be altered by MS_REMOUNT
 */
#define MS_RMT_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS|MS_MANDLOCK|MS_NOATIME)

/*
 * Magic mount flag number. Has to be or-ed to the flag values.
 */
#define MS_MGC_VAL 0xC0ED0000	/* magic flag number to indicate "new" flags */
#define MS_MGC_MSK 0xffff0000	/* magic flag number mask */

/*
 * Note that read-only etc flags are inode-specific: setting some file-system
 * flags just means all the inodes inherit those flags by default. It might be
 * possible to override it selectively if you really wanted to with some
 * ioctl() that is not currently implemented.
 *
 * Exception: MS_RDONLY is always applied to the entire file system.
 */
#define IS_RDONLY(inode) (((inode)->i_sb) && ((inode)->i_sb->s_flags & MS_RDONLY))
#define IS_NOSUID(inode) ((inode)->i_flags & MS_NOSUID)
#define IS_NODEV(inode) ((inode)->i_flags & MS_NODEV)
#define IS_NOEXEC(inode) ((inode)->i_flags & MS_NOEXEC)
#define IS_SYNC(inode) ((inode)->i_flags & MS_SYNCHRONOUS)
#define IS_MANDLOCK(inode) ((inode)->i_flags & MS_MANDLOCK)

#define IS_WRITABLE(inode) ((inode)->i_flags & S_WRITE)
#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE)
#define IS_NOATIME(inode) ((inode)->i_flags & MS_NOATIME)
#define IS_ZERO_WR(inode) ((inode)->i_flags & S_ZERO_WR)

typedef int (*filldir_t)(void *, const char *, int, off_t, ino_t);

struct iattr {
	unsigned int	ia_valid;
	umode_t		ia_mode;
	uid_t		ia_uid;
	gid_t		ia_gid;
	off_t		ia_size;
	time_t		ia_atime;
	time_t		ia_mtime;
	time_t		ia_ctime;
};

struct statfs {
	long f_type;
	long f_bsize;
	long f_blocks;
	long f_bfree;
	long f_bavail;
	long f_files;
	long f_ffree;
	/*__kernel_fsid_t f_fsid;*/
	long f_namelen;
	long f_spare[6];
};

struct super_operations {
	void (*read_inode) (struct inode *);
	int (*notify_change) (struct inode *, struct iattr *);
	void (*write_inode) (struct inode *);
	void (*put_inode) (struct inode *);
	void (*put_super) (struct super_block *);
	void (*write_super) (struct super_block *);
	void (*statfs) (struct super_block *, struct statfs *, int);
	int (*remount_fs) (struct super_block *, int *, char *);
};

struct file_system_type {
	struct super_block *(*read_super) (struct super_block *, void *, int);
	const char *name;
	int requires_dev;
	struct file_system_type * next;
};

struct super_block {
	kdev_t s_dev;
	unsigned long s_blocksize;
	unsigned char s_blocksize_bits;
	unsigned char s_lock;
	unsigned char s_rd_only;
	unsigned char s_dirt;
	struct file_system_type *s_type;
	struct super_operations *s_op;
	/*struct dquot_operations *dq_op;*/
	unsigned long s_flags;
	unsigned long s_magic;
	unsigned long s_time;
	struct inode * s_covered;
	struct inode * s_mounted;
	/*struct wait_queue * s_wait;TODO*/
	union {
		unsigned char i_ip_pad[40];
		void *generic_sbp;
	} u;
};


/*站位声明*/
struct vm_area_struct{
	long pad;
};
typedef struct select_table_struct {
	int nr;
	void *entry;
} select_table;

struct file_operations {
	int (*lseek) (struct inode *, struct file *, off_t, int);
	int (*read) (struct inode *, struct file *, char *, int);
	int (*write) (struct inode *, struct file *, const char *, int);
	int (*readdir) (struct inode *, struct file *, void *, filldir_t);
	int (*select) (struct inode *, struct file *, int, select_table *);
	int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
	int (*mmap) (struct inode *, struct file *, struct vm_area_struct *);
	int (*open) (struct inode *, struct file *);
	void (*release) (struct inode *, struct file *);
	int (*fsync) (struct inode *, struct file *);
	int (*fasync) (struct inode *, struct file *, int);
	int (*check_media_change) (kdev_t dev);
	int (*revalidate) (kdev_t dev);
};

struct inode_operations {
	struct file_operations * default_file_ops;
	int (*create) (struct inode *,const char *,int,int,struct inode **);
	int (*lookup) (struct inode *,const char *,int,struct inode **);
	int (*link) (struct inode *,struct inode *,const char *,int);
	int (*unlink) (struct inode *,const char *,int);
	int (*symlink) (struct inode *,const char *,int,const char *);
	int (*mkdir) (struct inode *,const char *,int,int);
	int (*rmdir) (struct inode *,const char *,int);
	int (*mknod) (struct inode *,const char *,int,int,int);
	int (*rename) (struct inode *,const char *,int,struct inode *,const char *,int, int);
	int (*readlink) (struct inode *,char *,int);
	int (*follow_link) (struct inode *,struct inode *,int,int,struct inode **);
	int (*readpage) (struct inode *, struct page *);
	int (*writepage) (struct inode *, struct page *);
	int (*bmap) (struct inode *,int);
	void (*truncate) (struct inode *);
	int (*permission) (struct inode *, int);
	int (*smap) (struct inode *,int);
};

struct inode {
	kdev_t		i_dev;
	unsigned long	i_ino;
	umode_t		i_mode;
	nlink_t		i_nlink;
	uid_t		i_uid;
	gid_t		i_gid;
	kdev_t		i_rdev;
	off_t		i_size;
	time_t		i_atime;
	time_t		i_mtime;
	time_t		i_ctime;
	unsigned long	i_blksize;
	unsigned long	i_blocks;
	unsigned long	i_version;
	unsigned long	i_nrpages;
	/*struct semaphore i_sem;*/
	struct inode_operations *i_op;
	struct super_block *i_sb;
	/*struct wait_queue *i_wait;
	struct file_lock *i_flock;
	struct page *i_pages;
	struct dquot *i_dquot[MAXQUOTAS];*/
	struct inode *i_next, *i_prev;
	struct inode *i_hash_next, *i_hash_prev;
	struct inode *i_bound_to, *i_bound_by;
	struct inode *i_mount;
	unsigned long i_count;	/* needs to be > (address_space * tasks)>>pagebits */
	unsigned short i_flags;
	unsigned short i_writecount;
	unsigned char i_lock;
	unsigned char i_dirt;
	unsigned char i_pipe;
	unsigned char i_sock;
	unsigned char i_seek;
	unsigned char i_update;
 	unsigned char i_condemned;
	union {
		unsigned char i_ip_pad[100];
		void * generic_ip;
	} u;
};

struct file {
	mode_t f_mode;
	loff_t f_pos;
	unsigned short f_flags;
	unsigned short f_count;
	unsigned long f_reada, f_ramax, f_raend, f_ralen, f_rawin;
	struct file *f_next, *f_prev;
	/*struct fown_struct f_owner;*/
	struct inode * f_inode;
	struct file_operations * f_op;
	unsigned long f_version;
	void *private_data;	/* needed for tty driver, and maybe others */
};

/*来自sched.h*/
struct fs_struct {
	int count;
	unsigned short umask;
	struct inode * root, * pwd;
};

extern struct file files_fd[NR_OPEN]; /*静态分配空间*/
extern struct fs_struct current_fs;
extern int current_fd;	 /*指向打开的文件槽*/

struct inode * iget(struct super_block * sb,int nr);
void iput(struct inode * inode);
unsigned long find_next_zero_bit(void *addr, unsigned long size, unsigned long offset);
struct file * fget(unsigned long fd);
void fput(struct file *file, struct inode *inode);

#define GFP_KERNEL 0
void *kmalloc(unsigned long size, char x);
void kfree( void *p );

struct inode * get_empty_inode(void);
int open_namei(const char * pathname, int flag, int mode,
               struct inode ** res_inode, struct inode * base);

int mf_open(char * filename,int flags,int mode);
int mf_close(unsigned int fd);
int mf_readdir(unsigned int fd, void * dirent, unsigned int count);
int mf_mkdir(const char * pathname, int mode);
long mf_lseek(unsigned int fd, off_t offset, unsigned int origin);
int mf_read(unsigned int fd,char * buf,int count);
int mf_write(unsigned int fd,char * buf,unsigned int count);        
int mf_unlink(const char * pathname); //文件删除
int mf_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg); //取文件长度
int mf_eof(unsigned int fd);
int mf_rename(const char * oldname, const char * newname, int must_be_dir);


#endif /*_FS_H*/