root/include/linux/fs.h

/* */

INCLUDED FROM

   1 #ifndef _LINUX_FS_H
   2 #define _LINUX_FS_H
   3 
   4 /*
   5  * This file has definitions for some important file table
   6  * structures etc.
   7  */
   8 
   9 #include <linux/linkage.h>
  10 #include <linux/limits.h>
  11 #include <linux/wait.h>
  12 #include <linux/types.h>
  13 #include <linux/dirent.h>
  14 #include <linux/vfs.h>
  15 
  16 /*
  17  * It's silly to have NR_OPEN bigger than NR_FILE, but I'll fix
  18  * that later. Anyway, now the file code is no longer dependent
  19  * on bitmaps in unsigned longs, but uses the new fd_set structure..
  20  *
  21  * Some programs (notably those using select()) may have to be 
  22  * recompiled to take full advantage of the new limits..
  23  */
  24 #undef NR_OPEN
  25 #define NR_OPEN 256
  26 
  27 #define NR_INODE 2048   /* this should be bigger than NR_FILE */
  28 #define NR_FILE 1024    /* this can well be larger on a larger system */
  29 #define NR_SUPER 32
  30 #define NR_HASH 997
  31 #define NR_IHASH 131
  32 #define NR_FILE_LOCKS 64
  33 #define BLOCK_SIZE 1024
  34 #define BLOCK_SIZE_BITS 10
  35 #define MAX_CHRDEV 32
  36 #define MAX_BLKDEV 32
  37 
  38 /* devices are as follows: (same as minix, so we can use the minix
  39  * file system. These are major numbers.)
  40  *
  41  *  0 - unnamed (minor 0 = true nodev)
  42  *  1 - /dev/mem
  43  *  2 - /dev/fd
  44  *  3 - /dev/hd
  45  *  4 - /dev/ttyx
  46  *  5 - /dev/tty
  47  *  6 - /dev/lp
  48  *  7 -
  49  *  8 - /dev/sd
  50  *  9 - /dev/st
  51  * 10 - mice
  52  * 11 - scsi cdrom
  53  * 12 -
  54  * 13 -
  55  * 14 - sound card (?)
  56  * 15 -
  57  */
  58 
  59 #define UNNAMED_MAJOR 0
  60 
  61 #define MAY_EXEC 1
  62 #define MAY_WRITE 2
  63 #define MAY_READ 4
  64 
  65 #define READ 0
  66 #define WRITE 1
  67 #define READA 2         /* read-ahead - don't pause */
  68 #define WRITEA 3        /* "write-ahead" - silly, but somewhat useful */
  69 
  70 extern void buffer_init(void);
  71 extern unsigned long inode_init(unsigned long start, unsigned long end);
  72 extern unsigned long file_table_init(unsigned long start, unsigned long end);
  73 
  74 #define MAJOR(a) (((unsigned)(a))>>8)
  75 #define MINOR(a) ((a)&0xff)
  76 
  77 #ifndef NULL
  78 #define NULL ((void *) 0)
  79 #endif
  80 
  81 #define NIL_FILP        ((struct file *)0)
  82 #define SEL_IN          1
  83 #define SEL_OUT         2
  84 #define SEL_EX          4
  85 
  86 /*
  87  * These are the fs-independent mount-flags: up to 16 flags are supported
  88  */
  89 #define MS_RDONLY    1 /* mount read-only */
  90 #define MS_NOSUID    2 /* ignore suid and sgid bits */
  91 #define MS_NODEV     4 /* disallow access to device special files */
  92 #define MS_NOEXEC    8 /* disallow program execution */
  93 #define MS_SYNC     16 /* writes are synced at once */
  94 #define MS_REMOUNT  32 /* alter flags of a mounted FS */
  95 
  96 /*
  97  * Flags that can be altered by MS_REMOUNT
  98  */
  99 #define MS_RMT_MASK (MS_RDONLY)
 100 
 101 /*
 102  * Magic mount flag number. Has to be or-ed to the flag values.
 103  */
 104 #define MS_MGC_VAL 0xC0ED0000 /* magic flag number to indicate "new" flags */
 105 #define MS_MGC_MSK 0xffff0000 /* magic flag number mask */
 106 
 107 /*
 108  * Note that read-only etc flags are inode-specific: setting some file-system
 109  * flags just means all the inodes inherit those flags by default. It might be
 110  * possible to overrride it sevelctively if you really wanted to with some
 111  * ioctl() that is not currently implemented.
 112  *
 113  * Exception: MS_RDONLY is always applied to the entire file system.
 114  */
 115 #define IS_RDONLY(inode) (((inode)->i_sb) && ((inode)->i_sb->s_flags & MS_RDONLY))
 116 #define IS_NOSUID(inode) ((inode)->i_flags & MS_NOSUID)
 117 #define IS_NODEV(inode) ((inode)->i_flags & MS_NODEV)
 118 #define IS_NOEXEC(inode) ((inode)->i_flags & MS_NOEXEC)
 119 #define IS_SYNC(inode) ((inode)->i_flags & MS_SYNC)
 120 
 121 /* the read-only stuff doesn't really belong here, but any other place is
 122    probably as bad and I don't want to create yet another include file. */
 123 
 124 #define BLKROSET 4701 /* set device read-only (0 = read-write) */
 125 #define BLKROGET 4702 /* get read-only status (0 = read_write) */
 126 #define BLKRRPART 4703 /* re-read partition table */
 127 #define BLKGETSIZE 4704 /* return device size */
 128 #define BLKFLSBUF 4705 /* flush buffer cache */
 129 
 130 /* These are a few other constants  only used by scsi  devices */
 131 
 132 #define SCSI_IOCTL_GET_IDLUN 0x5382
 133 
 134 
 135 #define BMAP_IOCTL 1    /* obsolete - kept for compatibility */
 136 #define FIBMAP     1    /* bmap access */
 137 #define FIGETBSZ   2    /* get the block size used for bmap */
 138 
 139 /* these flags tell notify_change what is being changed */
 140 
 141 #define NOTIFY_SIZE     1
 142 #define NOTIFY_MODE     2
 143 #define NOTIFY_TIME     4
 144 #define NOTIFY_UIDGID   8
 145 
 146 typedef char buffer_block[BLOCK_SIZE];
 147 
 148 struct buffer_head {
 149         char * b_data;                  /* pointer to data block (1024 bytes) */
 150         unsigned long b_size;           /* block size */
 151         unsigned long b_blocknr;        /* block number */
 152         dev_t b_dev;                    /* device (0 = free) */
 153         unsigned short b_count;         /* users using this block */
 154         unsigned char b_uptodate;
 155         unsigned char b_dirt;           /* 0-clean,1-dirty */
 156         unsigned char b_lock;           /* 0 - ok, 1 -locked */
 157         unsigned char b_req;            /* 0 if the buffer has been invalidated */
 158         struct wait_queue * b_wait;
 159         struct buffer_head * b_prev;            /* doubly linked list of hash-queue */
 160         struct buffer_head * b_next;
 161         struct buffer_head * b_prev_free;       /* doubly linked list of buffers */
 162         struct buffer_head * b_next_free;
 163         struct buffer_head * b_this_page;       /* circular list of buffers in one page */
 164         struct buffer_head * b_reqnext;         /* request queue */
 165 };
 166 
 167 #include <linux/pipe_fs_i.h>
 168 #include <linux/minix_fs_i.h>
 169 #include <linux/ext_fs_i.h>
 170 #include <linux/ext2_fs_i.h>
 171 #include <linux/msdos_fs_i.h>
 172 #include <linux/iso_fs_i.h>
 173 #include <linux/nfs_fs_i.h>
 174 #include <linux/xia_fs_i.h>
 175 
 176 struct inode {
 177         dev_t           i_dev;
 178         unsigned long   i_ino;
 179         umode_t         i_mode;
 180         nlink_t         i_nlink;
 181         uid_t           i_uid;
 182         gid_t           i_gid;
 183         dev_t           i_rdev;
 184         off_t           i_size;
 185         time_t          i_atime;
 186         time_t          i_mtime;
 187         time_t          i_ctime;
 188         unsigned long   i_blksize;
 189         unsigned long   i_blocks;
 190         struct inode_operations * i_op;
 191         struct super_block * i_sb;
 192         struct wait_queue * i_wait;
 193         struct file_lock * i_flock;
 194         struct vm_area_struct * i_mmap;
 195         struct inode * i_next, * i_prev;
 196         struct inode * i_hash_next, * i_hash_prev;
 197         struct inode * i_bound_to, * i_bound_by;
 198         unsigned short i_count;
 199         unsigned short i_flags;
 200         unsigned char i_lock;
 201         unsigned char i_dirt;
 202         unsigned char i_pipe;
 203         unsigned char i_mount;
 204         unsigned char i_seek;
 205         unsigned char i_update;
 206         union {
 207                 struct pipe_inode_info pipe_i;
 208                 struct minix_inode_info minix_i;
 209                 struct ext_inode_info ext_i;
 210                 struct ext2_inode_info ext2_i;
 211                 struct msdos_inode_info msdos_i;
 212                 struct iso_inode_info isofs_i;
 213                 struct nfs_inode_info nfs_i;
 214                 struct xiafs_inode_info xiafs_i;
 215         } u;
 216 };
 217 
 218 struct file {
 219         mode_t f_mode;
 220         dev_t f_rdev;                   /* needed for /dev/tty */
 221         off_t f_pos;
 222         unsigned short f_flags;
 223         unsigned short f_count;
 224         unsigned short f_reada;
 225         struct file *f_next, *f_prev;
 226         struct inode * f_inode;
 227         struct file_operations * f_op;
 228 };
 229 
 230 struct file_lock {
 231         struct file_lock *fl_next;      /* singly linked list */
 232         struct task_struct *fl_owner;   /* NULL if on free list, for sanity checks */
 233         unsigned int fl_fd;             /* File descriptor for this lock */
 234         struct wait_queue *fl_wait;
 235         char fl_type;
 236         char fl_whence;
 237         off_t fl_start;
 238         off_t fl_end;
 239 };
 240 
 241 #include <linux/minix_fs_sb.h>
 242 #include <linux/ext_fs_sb.h>
 243 #include <linux/ext2_fs_sb.h>
 244 #include <linux/msdos_fs_sb.h>
 245 #include <linux/iso_fs_sb.h>
 246 #include <linux/nfs_fs_sb.h>
 247 #include <linux/xia_fs_sb.h>
 248 
 249 struct super_block {
 250         dev_t s_dev;
 251         unsigned long s_blocksize;
 252         unsigned char s_blocksize_bits;
 253         unsigned char s_lock;
 254         unsigned char s_rd_only;
 255         unsigned char s_dirt;
 256         struct super_operations *s_op;
 257         unsigned long s_flags;
 258         unsigned long s_magic;
 259         unsigned long s_time;
 260         struct inode * s_covered;
 261         struct inode * s_mounted;
 262         struct wait_queue * s_wait;
 263         union {
 264                 struct minix_sb_info minix_sb;
 265                 struct ext_sb_info ext_sb;
 266                 struct ext2_sb_info ext2_sb;
 267                 struct msdos_sb_info msdos_sb;
 268                 struct isofs_sb_info isofs_sb;
 269                 struct nfs_sb_info nfs_sb;
 270                 struct xiafs_sb_info xiafs_sb;
 271         } u;
 272 };
 273 
 274 struct file_operations {
 275         int (*lseek) (struct inode *, struct file *, off_t, int);
 276         int (*read) (struct inode *, struct file *, char *, int);
 277         int (*write) (struct inode *, struct file *, char *, int);
 278         int (*readdir) (struct inode *, struct file *, struct dirent *, int);
 279         int (*select) (struct inode *, struct file *, int, select_table *);
 280         int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
 281         int (*mmap) (struct inode *, struct file *, unsigned long, size_t, int, unsigned long);
 282         int (*open) (struct inode *, struct file *);
 283         void (*release) (struct inode *, struct file *);
 284         int (*fsync) (struct inode *, struct file *);
 285 };
 286 
 287 struct inode_operations {
 288         struct file_operations * default_file_ops;
 289         int (*create) (struct inode *,const char *,int,int,struct inode **);
 290         int (*lookup) (struct inode *,const char *,int,struct inode **);
 291         int (*link) (struct inode *,struct inode *,const char *,int);
 292         int (*unlink) (struct inode *,const char *,int);
 293         int (*symlink) (struct inode *,const char *,int,const char *);
 294         int (*mkdir) (struct inode *,const char *,int,int);
 295         int (*rmdir) (struct inode *,const char *,int);
 296         int (*mknod) (struct inode *,const char *,int,int,int);
 297         int (*rename) (struct inode *,const char *,int,struct inode *,const char *,int);
 298         int (*readlink) (struct inode *,char *,int);
 299         int (*follow_link) (struct inode *,struct inode *,int,int,struct inode **);
 300         int (*bmap) (struct inode *,int);
 301         void (*truncate) (struct inode *);
 302         int (*permission) (struct inode *, int);
 303 };
 304 
 305 struct super_operations {
 306         void (*read_inode) (struct inode *);
 307         int (*notify_change) (int flags, struct inode *);
 308         void (*write_inode) (struct inode *);
 309         void (*put_inode) (struct inode *);
 310         void (*put_super) (struct super_block *);
 311         void (*write_super) (struct super_block *);
 312         void (*statfs) (struct super_block *, struct statfs *);
 313         int (*remount_fs) (struct super_block *, int *);
 314 };
 315 
 316 struct file_system_type {
 317         struct super_block *(*read_super) (struct super_block *, void *, int);
 318         char *name;
 319         int requires_dev;
 320 };
 321 
 322 #ifdef __KERNEL__
 323 
 324 asmlinkage int sys_open(const char *, int, int);
 325 asmlinkage int sys_close(unsigned int);         /* yes, it's really unsigned */
 326 
 327 extern int getname(const char * filename, char **result);
 328 extern void putname(char * name);
 329 
 330 extern int register_blkdev(unsigned int, const char *, struct file_operations *);
 331 extern int blkdev_open(struct inode * inode, struct file * filp);
 332 extern struct file_operations def_blk_fops;
 333 extern struct inode_operations blkdev_inode_operations;
 334 
 335 extern int register_chrdev(unsigned int, const char *, struct file_operations *);
 336 extern int chrdev_open(struct inode * inode, struct file * filp);
 337 extern struct file_operations def_chr_fops;
 338 extern struct inode_operations chrdev_inode_operations;
 339 
 340 extern void init_fifo(struct inode * inode);
 341 
 342 extern struct file_operations connecting_pipe_fops;
 343 extern struct file_operations read_pipe_fops;
 344 extern struct file_operations write_pipe_fops;
 345 extern struct file_operations rdwr_pipe_fops;
 346 
 347 extern struct file_system_type *get_fs_type(char *name);
 348 
 349 extern int fs_may_mount(dev_t dev);
 350 extern int fs_may_umount(dev_t dev, struct inode * mount_root);
 351 extern int fs_may_remount_ro(dev_t dev);
 352 
 353 extern struct file *first_file;
 354 extern int nr_files;
 355 extern struct super_block super_blocks[NR_SUPER];
 356 
 357 extern void grow_buffers(int size);
 358 extern int shrink_buffers(unsigned int priority);
 359 
 360 extern int nr_buffers;
 361 extern int buffermem;
 362 extern int nr_buffer_heads;
 363 
 364 extern void check_disk_change(dev_t dev);
 365 extern void invalidate_inodes(dev_t dev);
 366 extern void invalidate_buffers(dev_t dev);
 367 extern int floppy_change(struct buffer_head * first_block);
 368 extern void sync_inodes(dev_t dev);
 369 extern void sync_dev(dev_t dev);
 370 extern int fsync_dev(dev_t dev);
 371 extern void sync_supers(dev_t dev);
 372 extern int bmap(struct inode * inode,int block);
 373 extern int notify_change(int flags, struct inode * inode);
 374 extern int namei(const char * pathname, struct inode ** res_inode);
 375 extern int lnamei(const char * pathname, struct inode ** res_inode);
 376 extern int permission(struct inode * inode,int mask);
 377 extern int open_namei(const char * pathname, int flag, int mode,
 378         struct inode ** res_inode, struct inode * base);
 379 extern int do_mknod(const char * filename, int mode, dev_t dev);
 380 extern void iput(struct inode * inode);
 381 extern struct inode * __iget(struct super_block * sb,int nr,int crsmnt);
 382 extern struct inode * iget(struct super_block * sb,int nr);
 383 extern struct inode * get_empty_inode(void);
 384 extern void insert_inode_hash(struct inode *);
 385 extern void clear_inode(struct inode *);
 386 extern struct inode * get_pipe_inode(void);
 387 extern struct file * get_empty_filp(void);
 388 extern struct buffer_head * get_hash_table(dev_t dev, int block, int size);
 389 extern struct buffer_head * getblk(dev_t dev, int block, int size);
 390 extern void ll_rw_block(int rw, int nr, struct buffer_head * bh[]);
 391 extern void ll_rw_page(int rw, int dev, int nr, char * buffer);
 392 extern void ll_rw_swap_file(int rw, int dev, unsigned int *b, int nb, char *buffer);
 393 extern void brelse(struct buffer_head * buf);
 394 extern void set_blocksize(dev_t dev, int size);
 395 extern struct buffer_head * bread(dev_t dev, int block, int size);
 396 extern unsigned long bread_page(unsigned long addr,dev_t dev,int b[],int size,int prot);
 397 extern struct buffer_head * breada(dev_t dev,int block,...);
 398 extern void put_super(dev_t dev);
 399 extern dev_t ROOT_DEV;
 400 
 401 extern void mount_root(void);
 402 
 403 extern int char_read(struct inode *, struct file *, char *, int);
 404 extern int block_read(struct inode *, struct file *, char *, int);
 405 extern int read_ahead[];
 406 
 407 extern int char_write(struct inode *, struct file *, char *, int);
 408 extern int block_write(struct inode *, struct file *, char *, int);
 409 
 410 extern int generic_mmap(struct inode *, struct file *, unsigned long, size_t, int, unsigned long);
 411 
 412 extern int block_fsync(struct inode *, struct file *);
 413 extern int file_fsync(struct inode *, struct file *);
 414 
 415 #endif /* __KERNEL__ */
 416 
 417 #endif

/* */