fs.h

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#ifndef _LINUX_FS_H
#define _LINUX_FS_H

/**
*

 * This file has definitions for some important file table
 * structures etc.


*/

#include <linux/linkage.h>
#include <linux/limits.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <linux/dirent.h>
#include <linux/vfs.h>
#include <linux/net.h>

/**
*

 * It's silly to have NR_OPEN bigger than NR_FILE, but I'll fix
 * that later. Anyway, now the file code is no longer dependent
 * on bitmaps in unsigned longs, but uses the new fd_set structure..
 *
 * Some programs (notably those using select()) may have to be 
 * recompiled to take full advantage of the new limits..


*/
#undef NR_OPEN
#define NR_OPEN 256

#define NR_INODE 2048   ///< this should be bigger than NR_FILE 
#define NR_FILE 1024    ///< this can well be larger on a larger system 
#define NR_SUPER 32
#define NR_HASH 997
#define NR_IHASH 131
#define NR_FILE_LOCKS 64
#define BLOCK_SIZE 1024
#define BLOCK_SIZE_BITS 10

#define MAY_EXEC 1
#define MAY_WRITE 2
#define MAY_READ 4

#define READ 0
#define WRITE 1
#define READA 2         ///< read-ahead - don't pause 
#define WRITEA 3        ///< "write-ahead" - silly, but somewhat useful 

extern void buffer_init(void);
extern unsigned long inode_init(unsigned long start, unsigned long end);
extern unsigned long file_table_init(unsigned long start, unsigned long end);

#define MAJOR(a) (int)((unsigned short)(a) >> 8)
#define MINOR(a) (int)((unsigned short)(a) & 0xFF)
#define MKDEV(a,b) ((int)((((a) & 0xff) << 8) | ((b) & 0xff)))

#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_SYNC     16 ///< writes are synced at once 
#define MS_REMOUNT  32 ///< alter flags of a mounted FS 

/**
*

 * Flags that can be altered by MS_REMOUNT


*/
#define MS_RMT_MASK (MS_RDONLY)

/**
*

 * 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 overrride it sevelctively 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_SYNC)

/**
*
 the read-only stuff doesn't really belong here, but any other place is


*/

#define BLKROSET 4701 ///< set device read-only (0 = read-write) 
#define BLKROGET 4702 ///< get read-only status (0 = read_write) 
#define BLKRRPART 4703 ///< re-read partition table 
#define BLKGETSIZE 4704 ///< return device size 
#define BLKFLSBUF 4705 ///< flush buffer cache 

/// These are a few other constants  only used by scsi  devices 

#define SCSI_IOCTL_GET_IDLUN 0x5382

/// Used to turn on and off tagged queueing for scsi devices 

#define SCSI_IOCTL_TAGGED_ENABLE 0x5383
#define SCSI_IOCTL_TAGGED_DISABLE 0x5384


#define BMAP_IOCTL 1    ///< obsolete - kept for compatibility 
#define FIBMAP     1    ///< bmap access 
#define FIGETBSZ   2    ///< get the block size used for bmap 

/// these flags tell notify_change what is being changed 

#define NOTIFY_SIZE     1
#define NOTIFY_MODE     2
#define NOTIFY_TIME     4
#define NOTIFY_UIDGID   8

typedef char buffer_block[BLOCK_SIZE];

struct buffer_head {
        char * b_data;                  ///< pointer to data block (1024 bytes) 
        unsigned long b_size;           ///< block size 
        unsigned long b_blocknr;        ///< block number 
        dev_t b_dev;                    ///< device (0 = free) 
        unsigned short b_count;         ///< users using this block 
        unsigned char b_uptodate;
        unsigned char b_dirt;           ///< 0-clean,1-dirty 
        unsigned char b_lock;           ///< 0 - ok, 1 -locked 
        unsigned char b_req;            ///< 0 if the buffer has been invalidated 
        struct wait_queue * b_wait;
        struct buffer_head * b_prev;            ///< doubly linked list of hash-queue 
        struct buffer_head * b_next;
        struct buffer_head * b_prev_free;       ///< doubly linked list of buffers 
        struct buffer_head * b_next_free;
        struct buffer_head * b_this_page;       ///< circular list of buffers in one page 
        struct buffer_head * b_reqnext;         ///< request queue 
};

#include <linux/pipe_fs_i.h>
#include <linux/minix_fs_i.h>
#include <linux/ext_fs_i.h>
#include <linux/ext2_fs_i.h>
#include <linux/hpfs_fs_i.h>
#include <linux/msdos_fs_i.h>
#include <linux/iso_fs_i.h>
#include <linux/nfs_fs_i.h>
#include <linux/xia_fs_i.h>
#include <linux/sysv_fs_i.h>

struct inode {
        dev_t           i_dev;
        unsigned long   i_ino;
        umode_t         i_mode;
        nlink_t         i_nlink;
        uid_t           i_uid;
        gid_t           i_gid;
        dev_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;
        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 vm_area_struct * i_mmap;
        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;
        struct socket * i_socket;
        unsigned short i_count;
        unsigned short i_flags;
        unsigned char i_lock;
        unsigned char i_dirt;
        unsigned char i_pipe;
        unsigned char i_seek;
        unsigned char i_update;
        union {
                struct pipe_inode_info pipe_i;
                struct minix_inode_info minix_i;
                struct ext_inode_info ext_i;
                struct ext2_inode_info ext2_i;
                struct hpfs_inode_info hpfs_i;
                struct msdos_inode_info msdos_i;
                struct iso_inode_info isofs_i;
                struct nfs_inode_info nfs_i;
                struct xiafs_inode_info xiafs_i;
                struct sysv_inode_info sysv_i;
        } u;
};

struct file {
        mode_t f_mode;
        dev_t f_rdev;                   ///< needed for /dev/tty 
        off_t f_pos;
        unsigned short f_flags;
        unsigned short f_count;
        unsigned short f_reada;
        struct file *f_next, *f_prev;
        struct inode * f_inode;
        struct file_operations * f_op;
};

struct file_lock {
        struct file_lock *fl_next;      ///< singly linked list 
        struct task_struct *fl_owner;   ///< NULL if on free list, for sanity checks 
        unsigned int fl_fd;             ///< File descriptor for this lock 
        struct wait_queue *fl_wait;
        char fl_type;
        char fl_whence;
        off_t fl_start;
        off_t fl_end;
};

#include <linux/minix_fs_sb.h>
#include <linux/ext_fs_sb.h>
#include <linux/ext2_fs_sb.h>
#include <linux/hpfs_fs_sb.h>
#include <linux/msdos_fs_sb.h>
#include <linux/iso_fs_sb.h>
#include <linux/nfs_fs_sb.h>
#include <linux/xia_fs_sb.h>
#include <linux/sysv_fs_sb.h>

struct super_block {
        dev_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 super_operations *s_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;
        union {
                struct minix_sb_info minix_sb;
                struct ext_sb_info ext_sb;
                struct ext2_sb_info ext2_sb;
                struct hpfs_sb_info hpfs_sb;
                struct msdos_sb_info msdos_sb;
                struct isofs_sb_info isofs_sb;
                struct nfs_sb_info nfs_sb;
                struct xiafs_sb_info xiafs_sb;
                struct sysv_sb_info sysv_sb;
        } u;
};

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 *, char *, int);
        int (*readdir) (struct inode *, struct file *, struct dirent *, int);
        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 *, unsigned long, size_t, int, unsigned long);
        int (*open) (struct inode *, struct file *);
        void (*release) (struct inode *, struct file *);
        int (*fsync) (struct inode *, struct file *);
};

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 (*readlink) (struct inode *,char *,int);
        int (*follow_link) (struct inode *,struct inode *,int,int,struct inode **);
        int (*bmap) (struct inode *,int);
        void (*truncate) (struct inode *);
        int (*permission) (struct inode *, int);
};

struct super_operations {
        void (*read_inode) (struct inode *);
        int (*notify_change) (int flags, struct inode *);
        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 (*remount_fs) (struct super_block *, int *, char *);
};

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

#ifdef __KERNEL__

asmlinkage int sys_open(const char *, int, int);
asmlinkage int sys_close(unsigned int);         ///< yes, it's really unsigned 

extern int getname(const char * filename, char **result);
extern void putname(char * name);

extern int register_blkdev(unsigned int, const char *, struct file_operations *);
extern int unregister_blkdev(unsigned int major, const char * name);
extern int blkdev_open(struct inode * inode, struct file * filp);
extern struct file_operations def_blk_fops;
extern struct inode_operations blkdev_inode_operations;

extern int register_chrdev(unsigned int, const char *, struct file_operations *);
extern int unregister_chrdev(unsigned int major, const char * name);
extern int chrdev_open(struct inode * inode, struct file * filp);
extern struct file_operations def_chr_fops;
extern struct inode_operations chrdev_inode_operations;

extern void init_fifo(struct inode * inode);

extern struct file_operations connecting_fifo_fops;
extern struct file_operations read_fifo_fops;
extern struct file_operations write_fifo_fops;
extern struct file_operations rdwr_fifo_fops;
extern struct file_operations read_pipe_fops;
extern struct file_operations write_pipe_fops;
extern struct file_operations rdwr_pipe_fops;

extern struct file_system_type *get_fs_type(char *name);

extern int fs_may_mount(dev_t dev);
extern int fs_may_umount(dev_t dev, struct inode * mount_root);
extern int fs_may_remount_ro(dev_t dev);

extern struct file *first_file;
extern int nr_files;
extern struct super_block super_blocks[NR_SUPER];

extern int shrink_buffers(unsigned int priority);

extern int nr_buffers;
extern int buffermem;
extern int nr_buffer_heads;

extern void check_disk_change(dev_t dev);
extern void invalidate_inodes(dev_t dev);
extern void invalidate_buffers(dev_t dev);
extern int floppy_change(struct buffer_head * first_block);
extern void sync_inodes(dev_t dev);
extern void sync_dev(dev_t dev);
extern int fsync_dev(dev_t dev);
extern void sync_supers(dev_t dev);
extern int bmap(struct inode * inode,int block);
extern int notify_change(int flags, struct inode * inode);
extern int namei(const char * pathname, struct inode ** res_inode);
extern int lnamei(const char * pathname, struct inode ** res_inode);
extern int permission(struct inode * inode,int mask);
extern int open_namei(const char * pathname, int flag, int mode,
        struct inode ** res_inode, struct inode * base);
extern int do_mknod(const char * filename, int mode, dev_t dev);
extern void iput(struct inode * inode);
extern struct inode * __iget(struct super_block * sb,int nr,int crsmnt);
extern struct inode * iget(struct super_block * sb,int nr);
extern struct inode * get_empty_inode(void);
extern void insert_inode_hash(struct inode *);
extern void clear_inode(struct inode *);
extern struct inode * get_pipe_inode(void);
extern struct file * get_empty_filp(void);
extern struct buffer_head * get_hash_table(dev_t dev, int block, int size);
extern struct buffer_head * getblk(dev_t dev, int block, int size);
extern void ll_rw_block(int rw, int nr, struct buffer_head * bh[]);
extern void ll_rw_page(int rw, int dev, int nr, char * buffer);
extern void ll_rw_swap_file(int rw, int dev, unsigned int *b, int nb, char *buffer);
extern void brelse(struct buffer_head * buf);
extern void set_blocksize(dev_t dev, int size);
extern struct buffer_head * bread(dev_t dev, int block, int size);
extern unsigned long bread_page(unsigned long addr,dev_t dev,int b[],int size,int prot);
extern struct buffer_head * breada(dev_t dev,int block,...);
extern void put_super(dev_t dev);
extern dev_t ROOT_DEV;

extern void show_buffers(void);
extern void mount_root(void);

extern int char_read(struct inode *, struct file *, char *, int);
extern int block_read(struct inode *, struct file *, char *, int);
extern int read_ahead[];

extern int char_write(struct inode *, struct file *, char *, int);
extern int block_write(struct inode *, struct file *, char *, int);

extern int generic_mmap(struct inode *, struct file *, unsigned long, size_t, int, unsigned long);

extern int block_fsync(struct inode *, struct file *);
extern int file_fsync(struct inode *, struct file *);

#endif // __KERNEL__ 

#endif

---