include/linux/fs.h

   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/config.h>
  10 #include <linux/linkage.h>
  11 #include <linux/limits.h>
  12 #include <linux/wait.h>
  13 #include <linux/types.h>
  14 #include <linux/vfs.h>
  15 #include <linux/net.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/ioctl.h>
  18 #include <linux/list.h>
  19 #include <linux/dcache.h>
  20 #include <linux/stat.h>
  21
  22 #include <asm/atomic.h>
  23 #include <asm/bitops.h>
  24 #include <asm/cache.h>
  25
  26 struct poll_table_struct;
  27
  28
  29 /*
  30  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
  31  * the file limit at runtime and only root can increase the per-process
  32  * nr_file rlimit, so it's safe to set up a ridiculously high absolute
  33  * upper limit on files-per-process.
  34  *
  35  * Some programs (notably those using select()) may have to be
  36  * recompiled to take full advantage of the new limits..
  37  */
  38
  39 /* Fixed constants first: */
  40 #undef NR_OPEN
  41 #define NR_OPEN (1024*1024)     /* Absolute upper limit on fd num */
  42 #define INR_OPEN 1024           /* Initial setting for nfile rlimits */
  43
  44 #define BLOCK_SIZE_BITS 10
  45 #define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
  46
  47 /* And dynamically-tunable limits and defaults: */
  48 extern int max_files, nr_files, nr_free_files;
  49 extern int max_super_blocks, nr_super_blocks;
  50
  51 #define NR_FILE  8192   /* this can well be larger on a larger system */
  52 #define NR_RESERVED_FILES 10 /* reserved for root */
  53 #define NR_SUPER 256
  54
  55 #define MAY_EXEC 1
  56 #define MAY_WRITE 2
  57 #define MAY_READ 4
  58
  59 #define FMODE_READ 1
  60 #define FMODE_WRITE 2
  61
  62 #define READ 0
  63 #define WRITE 1
  64 #define READA 2         /* read-ahead  - don't block if no resources */
  65
  66 #define WRITERAW 5      /* raw write - don't play with buffer lists */
  67
  68 #ifndef NULL
  69 #define NULL ((void *) 0)
  70 #endif
  71
  72 #define NIL_FILP        ((struct file *)0)
  73 #define SEL_IN          1
  74 #define SEL_OUT         2
  75 #define SEL_EX          4
  76
  77 /* public flags for file_system_type */
  78 #define FS_REQUIRES_DEV 1
  79 #define FS_NO_DCACHE    2 /* Only dcache the necessary things. */
  80 #define FS_NO_PRELIM    4 /* prevent preloading of dentries, even if
  81                            * FS_NO_DCACHE is not set.
  82                            */
  83 #define FS_IBASKET      8 /* FS does callback to free_ibasket() if space gets low. */
  84
  85 /*
  86  * These are the fs-independent mount-flags: up to 16 flags are supported
  87  */
  88 #define MS_RDONLY        1      /* Mount read-only */
  89 #define MS_NOSUID        2      /* Ignore suid and sgid bits */
  90 #define MS_NODEV         4      /* Disallow access to device special files */
  91 #define MS_NOEXEC        8      /* Disallow program execution */
  92 #define MS_SYNCHRONOUS  16      /* Writes are synced at once */
  93 #define MS_REMOUNT      32      /* Alter flags of a mounted FS */
  94 #define MS_MANDLOCK     64      /* Allow mandatory locks on an FS */
  95 #define S_QUOTA         128     /* Quota initialized for file/directory/symlink */
  96 #define S_APPEND        256     /* Append-only file */
  97 #define S_IMMUTABLE     512     /* Immutable file */
  98 #define MS_NOATIME      1024    /* Do not update access times. */
  99 #define MS_NODIRATIME   2048    /* Do not update directory access times */
 100
 101 #define MS_ODD_RENAME   32768   /* Temporary stuff; will go away as soon
 102                                   * as nfs_rename() will be cleaned up
 103                                   */
 104
 105 /*
 106  * Flags that can be altered by MS_REMOUNT
 107  */
 108 #define MS_RMT_MASK     (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|\
 109                         MS_SYNCHRONOUS|MS_MANDLOCK|MS_NOATIME|MS_NODIRATIME)
 110
 111 /*
 112  * Magic mount flag number. Has to be or-ed to the flag values.
 113  */
 114 #define MS_MGC_VAL 0xC0ED0000   /* magic flag number to indicate "new" flags */
 115 #define MS_MGC_MSK 0xffff0000   /* magic flag number mask */
 116
 117 /*
 118  * Note that nosuid etc flags are inode-specific: setting some file-system
 119  * flags just means all the inodes inherit those flags by default. It might be
 120  * possible to override it selectively if you really wanted to with some
 121  * ioctl() that is not currently implemented.
 122  *
 123  * Exception: MS_RDONLY is always applied to the entire file system.
 124  *
 125  * Unfortunately, it is possible to change a filesystems flags with it mounted
 126  * with files in use.  This means that all of the inodes will not have their
 127  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
 128  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
 129  */
 130 #define __IS_FLG(inode,flg) (((inode)->i_sb && (inode)->i_sb->s_flags & (flg)) \
 131                                 || (inode)->i_flags & (flg))
 132
 133 #define IS_RDONLY(inode) (((inode)->i_sb) && ((inode)->i_sb->s_flags & MS_RDONLY))
 134 #define IS_NOSUID(inode)        __IS_FLG(inode, MS_NOSUID)
 135 #define IS_NODEV(inode)         __IS_FLG(inode, MS_NODEV)
 136 #define IS_NOEXEC(inode)        __IS_FLG(inode, MS_NOEXEC)
 137 #define IS_SYNC(inode)          __IS_FLG(inode, MS_SYNCHRONOUS)
 138 #define IS_MANDLOCK(inode)      __IS_FLG(inode, MS_MANDLOCK)
 139
 140 #define IS_QUOTAINIT(inode)     ((inode)->i_flags & S_QUOTA)
 141 #define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
 142 #define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
 143 #define IS_NOATIME(inode)       __IS_FLG(inode, MS_NOATIME)
 144 #define IS_NODIRATIME(inode)    __IS_FLG(inode, MS_NODIRATIME)
 145
 146
 147 /* the read-only stuff doesn't really belong here, but any other place is
 148    probably as bad and I don't want to create yet another include file. */
 149
 150 #define BLKROSET   _IO(0x12,93) /* set device read-only (0 = read-write) */
 151 #define BLKROGET   _IO(0x12,94) /* get read-only status (0 = read_write) */
 152 #define BLKRRPART  _IO(0x12,95) /* re-read partition table */
 153 #define BLKGETSIZE _IO(0x12,96) /* return device size */
 154 #define BLKFLSBUF  _IO(0x12,97) /* flush buffer cache */
 155 #define BLKRASET   _IO(0x12,98) /* Set read ahead for block device */
 156 #define BLKRAGET   _IO(0x12,99) /* get current read ahead setting */
 157 #define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
 158 #define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
 159 #define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
 160 #define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
 161 #define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
 162 #if 0
 163 #define BLKPG      _IO(0x12,105)/* See blkpg.h */
 164 /* This was here just to show that the number is taken -
 165    probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
 166 #endif
 167
 168
 169 #define BMAP_IOCTL 1            /* obsolete - kept for compatibility */
 170 #define FIBMAP     _IO(0x00,1)  /* bmap access */
 171 #define FIGETBSZ   _IO(0x00,2)  /* get the block size used for bmap */
 172
 173 #ifdef __KERNEL__
 174
 175 #include <asm/semaphore.h>
 176 #include <asm/byteorder.h>
 177
 178 extern void update_atime (struct inode *);
 179 #define UPDATE_ATIME(inode) update_atime (inode)
 180
 181 extern void buffer_init(unsigned long);
 182 extern void inode_init(void);
 183 extern void file_table_init(void);
 184 extern void dcache_init(void);
 185
 186 typedef char buffer_block[BLOCK_SIZE];
 187
 188 /* bh state bits */
 189 #define BH_Uptodate     0       /* 1 if the buffer contains valid data */
 190 #define BH_Dirty        1       /* 1 if the buffer is dirty */
 191 #define BH_Lock         2       /* 1 if the buffer is locked */
 192 #define BH_Req          3       /* 0 if the buffer has been invalidated */
 193 #define BH_Mapped       4       /* 1 if the buffer has a disk mapping */
 194 #define BH_New          5       /* 1 if the buffer is new and not yet written out */
 195 #define BH_Protected    6       /* 1 if the buffer is protected */
 196
 197 /*
 198  * Try to keep the most commonly used fields in single cache lines (16
 199  * bytes) to improve performance.  This ordering should be
 200  * particularly beneficial on 32-bit processors.
 201  *
 202  * We use the first 16 bytes for the data which is used in searches
 203  * over the block hash lists (ie. getblk() and friends).
 204  *
 205  * The second 16 bytes we use for lru buffer scans, as used by
 206  * sync_buffers() and refill_freelist().  -- sct
 207  */
 208 struct buffer_head {
 209         /* First cache line: */
 210         struct buffer_head *b_next;     /* Hash queue list */
 211         unsigned long b_blocknr;        /* block number */
 212         unsigned short b_size;          /* block size */
 213         unsigned short b_list;          /* List that this buffer appears */
 214         kdev_t b_dev;                   /* device (B_FREE = free) */
 215
 216         atomic_t b_count;               /* users using this block */
 217         kdev_t b_rdev;                  /* Real device */
 218         unsigned long b_state;          /* buffer state bitmap (see above) */
 219         unsigned long b_flushtime;      /* Time when (dirty) buffer should be written */
 220
 221         struct buffer_head *b_next_free;/* lru/free list linkage */
 222         struct buffer_head *b_prev_free;/* doubly linked list of buffers */
 223         struct buffer_head *b_this_page;/* circular list of buffers in one page */
 224         struct buffer_head *b_reqnext;  /* request queue */
 225
 226         struct buffer_head **b_pprev;   /* doubly linked list of hash-queue */
 227         char * b_data;                  /* pointer to data block (512 byte) */
 228         struct page *b_page;            /* the page this bh is mapped to */
 229         void (*b_end_io)(struct buffer_head *bh, int uptodate); /* I/O completion */
 230         void *b_dev_id;
 231
 232         unsigned long b_rsector;        /* Real buffer location on disk */
 233         wait_queue_head_t b_wait;
 234         struct kiobuf * b_kiobuf;       /* kiobuf which owns this IO */
 235 };
 236
 237 typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
 238 void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
 239
 240 #define __buffer_state(bh, state)       (((bh)->b_state & (1UL << BH_##state)) != 0)
 241
 242 #define buffer_uptodate(bh)     __buffer_state(bh,Uptodate)
 243 #define buffer_dirty(bh)        __buffer_state(bh,Dirty)
 244 #define buffer_locked(bh)       __buffer_state(bh,Lock)
 245 #define buffer_req(bh)          __buffer_state(bh,Req)
 246 #define buffer_mapped(bh)       __buffer_state(bh,Mapped)
 247 #define buffer_new(bh)          __buffer_state(bh,New)
 248 #define buffer_protected(bh)    __buffer_state(bh,Protected)
 249
 250 #define bh_offset(bh)           ((unsigned long)(bh)->b_data & ~PAGE_MASK)
 251
 252 extern void set_bh_page(struct buffer_head *bh, struct page *page, unsigned int offset);
 253
 254 #define touch_buffer(bh)        set_bit(PG_referenced, &bh->b_page->flags)
 255
 256 #include <linux/pipe_fs_i.h>
 257 #include <linux/minix_fs_i.h>
 258 #include <linux/ext2_fs_i.h>
 259 #include <linux/hpfs_fs_i.h>
 260 #include <linux/ntfs_fs_i.h>
 261 #include <linux/msdos_fs_i.h>
 262 #include <linux/umsdos_fs_i.h>
 263 #include <linux/iso_fs_i.h>
 264 #include <linux/nfs_fs_i.h>
 265 #include <linux/sysv_fs_i.h>
 266 #include <linux/affs_fs_i.h>
 267 #include <linux/ufs_fs_i.h>
 268 #include <linux/efs_fs_i.h>
 269 #include <linux/coda_fs_i.h>
 270 #include <linux/romfs_fs_i.h>
 271 #include <linux/smb_fs_i.h>
 272 #include <linux/hfs_fs_i.h>
 273 #include <linux/adfs_fs_i.h>
 274 #include <linux/qnx4_fs_i.h>
 275 #include <linux/bfs_fs_i.h>
 276 #include <linux/udf_fs_i.h>
 277 #include <linux/ncp_fs_i.h>
 278 #include <linux/proc_fs_i.h>
 279
 280 /*
 281  * Attribute flags.  These should be or-ed together to figure out what
 282  * has been changed!
 283  */
 284 #define ATTR_MODE       1
 285 #define ATTR_UID        2
 286 #define ATTR_GID        4
 287 #define ATTR_SIZE       8
 288 #define ATTR_ATIME      16
 289 #define ATTR_MTIME      32
 290 #define ATTR_CTIME      64
 291 #define ATTR_ATIME_SET  128
 292 #define ATTR_MTIME_SET  256
 293 #define ATTR_FORCE      512     /* Not a change, but a change it */
 294 #define ATTR_ATTR_FLAG  1024
 295
 296 /*
 297  * This is the Inode Attributes structure, used for notify_change().  It
 298  * uses the above definitions as flags, to know which values have changed.
 299  * Also, in this manner, a Filesystem can look at only the values it cares
 300  * about.  Basically, these are the attributes that the VFS layer can
 301  * request to change from the FS layer.
 302  *
 303  * Derek Atkins <warlord@MIT.EDU> 94-10-20
 304  */
 305 struct iattr {
 306         unsigned int    ia_valid;
 307         umode_t         ia_mode;
 308         uid_t           ia_uid;
 309         gid_t           ia_gid;
 310         loff_t          ia_size;
 311         time_t          ia_atime;
 312         time_t          ia_mtime;
 313         time_t          ia_ctime;
 314         unsigned int    ia_attr_flags;
 315 };
 316
 317 /*
 318  * This is the inode attributes flag definitions
 319  */
 320 #define ATTR_FLAG_SYNCRONOUS    1       /* Syncronous write */
 321 #define ATTR_FLAG_NOATIME       2       /* Don't update atime */
 322 #define ATTR_FLAG_APPEND        4       /* Append-only file */
 323 #define ATTR_FLAG_IMMUTABLE     8       /* Immutable file */
 324 #define ATTR_FLAG_NODIRATIME    16      /* Don't update atime for directory */
 325
 326 /*
 327  * Includes for diskquotas and mount structures.
 328  */
 329 #include <linux/quota.h>
 330 #include <linux/mount.h>
 331
 332 /*
 333  * oh the beauties of C type declarations.
 334  */
 335 struct page;
 336
 337 struct address_space {
 338         struct list_head        pages;
 339         unsigned long           nrpages;
 340 };
 341
 342 struct inode {
 343         struct list_head        i_hash;
 344         struct list_head        i_list;
 345         struct list_head        i_dentry;
 346
 347         unsigned long           i_ino;
 348         unsigned int            i_count;
 349         kdev_t                  i_dev;
 350         umode_t                 i_mode;
 351         nlink_t                 i_nlink;
 352         uid_t                   i_uid;
 353         gid_t                   i_gid;
 354         kdev_t                  i_rdev;
 355         loff_t                  i_size;
 356         time_t                  i_atime;
 357         time_t                  i_mtime;
 358         time_t                  i_ctime;
 359         unsigned long           i_blksize;
 360         unsigned long           i_blocks;
 361         unsigned long           i_version;
 362         struct semaphore        i_sem;
 363         struct inode_operations *i_op;
 364         struct super_block      *i_sb;
 365         wait_queue_head_t       i_wait;
 366         struct file_lock        *i_flock;
 367         struct vm_area_struct   *i_mmap;
 368         struct address_space    i_data;
 369         spinlock_t              i_shared_lock;
 370         struct dquot            *i_dquot[MAXQUOTAS];
 371         struct pipe_inode_info  *i_pipe;
 372
 373         unsigned long           i_state;
 374
 375         unsigned int            i_flags;
 376         unsigned char           i_sock;
 377
 378         atomic_t                i_writecount;
 379         unsigned int            i_attr_flags;
 380         __u32                   i_generation;
 381         union {
 382                 struct minix_inode_info         minix_i;
 383                 struct ext2_inode_info          ext2_i;
 384                 struct hpfs_inode_info          hpfs_i;
 385                 struct ntfs_inode_info          ntfs_i;
 386                 struct msdos_inode_info         msdos_i;
 387                 struct umsdos_inode_info        umsdos_i;
 388                 struct iso_inode_info           isofs_i;
 389                 struct nfs_inode_info           nfs_i;
 390                 struct sysv_inode_info          sysv_i;
 391                 struct affs_inode_info          affs_i;
 392                 struct ufs_inode_info           ufs_i;
 393                 struct efs_inode_info           efs_i;
 394                 struct romfs_inode_info         romfs_i;
 395                 struct coda_inode_info          coda_i;
 396                 struct smb_inode_info           smbfs_i;
 397                 struct hfs_inode_info           hfs_i;
 398                 struct adfs_inode_info          adfs_i;
 399                 struct qnx4_inode_info          qnx4_i;
 400                 struct bfs_inode_info           bfs_i;
 401                 struct udf_inode_info           udf_i;
 402                 struct ncp_inode_info           ncpfs_i;
 403                 struct proc_inode_info          proc_i;
 404                 struct socket                   socket_i;
 405                 void                            *generic_ip;
 406         } u;
 407 };
 408
 409 /* Inode state bits.. */
 410 #define I_DIRTY         1
 411 #define I_LOCK          2
 412 #define I_FREEING       4
 413
 414 extern void __mark_inode_dirty(struct inode *);
 415 static inline void mark_inode_dirty(struct inode *inode)
 416 {
 417         if (!(inode->i_state & I_DIRTY))
 418                 __mark_inode_dirty(inode);
 419 }
 420
 421 struct fown_struct {
 422         int pid;                /* pid or -pgrp where SIGIO should be sent */
 423         uid_t uid, euid;        /* uid/euid of process setting the owner */
 424         int signum;             /* posix.1b rt signal to be delivered on IO */
 425 };
 426
 427 struct file {
 428         struct list_head        f_list;
 429         struct dentry           *f_dentry;
 430         struct file_operations  *f_op;
 431         atomic_t                f_count;
 432         unsigned int            f_flags;
 433         mode_t                  f_mode;
 434         loff_t                  f_pos;
 435         unsigned long           f_reada, f_ramax, f_raend, f_ralen, f_rawin;
 436         struct fown_struct      f_owner;
 437         unsigned int            f_uid, f_gid;
 438         int                     f_error;
 439
 440         unsigned long           f_version;
 441
 442         /* needed for tty driver, and maybe others */
 443         void                    *private_data;
 444 };
 445 extern spinlock_t files_lock;
 446 #define file_list_lock() spin_lock(&files_lock);
 447 #define file_list_unlock() spin_unlock(&files_lock);
 448
 449 #define get_file(x)     atomic_inc(&(x)->f_count)
 450 #define file_count(x)   atomic_read(&(x)->f_count)
 451
 452 extern int init_private_file(struct file *, struct dentry *, int);
 453
 454 #define FL_POSIX        1
 455 #define FL_FLOCK        2
 456 #define FL_BROKEN       4       /* broken flock() emulation */
 457 #define FL_ACCESS       8       /* for processes suspended by mandatory locking */
 458 #define FL_LOCKD        16      /* lock held by rpc.lockd */
 459
 460 /*
 461  * The POSIX file lock owner is determined by
 462  * the "struct files_struct" in the thread group
 463  * (or NULL for no owner - BSD locks).
 464  *
 465  * Lockd stuffs a "host" pointer into this.
 466  */
 467 typedef struct files_struct *fl_owner_t;
 468
 469 struct file_lock {
 470         struct file_lock *fl_next;      /* singly linked list for this inode  */
 471         struct file_lock *fl_nextlink;  /* doubly linked list of all locks */
 472         struct file_lock *fl_prevlink;  /* used to simplify lock removal */
 473         struct file_lock *fl_nextblock; /* circular list of blocked processes */
 474         struct file_lock *fl_prevblock;
 475         fl_owner_t fl_owner;
 476         unsigned int fl_pid;
 477         wait_queue_head_t fl_wait;
 478         struct file *fl_file;
 479         unsigned char fl_flags;
 480         unsigned char fl_type;
 481         off_t fl_start;
 482         off_t fl_end;
 483
 484         void (*fl_notify)(struct file_lock *);  /* unblock callback */
 485
 486         union {
 487                 struct nfs_lock_info    nfs_fl;
 488         } fl_u;
 489 };
 490
 491 extern struct file_lock                 *file_lock_table;
 492
 493 #include <linux/fcntl.h>
 494
 495 extern int fcntl_getlk(unsigned int, struct flock *);
 496 extern int fcntl_setlk(unsigned int, unsigned int, struct flock *);
 497
 498 /* fs/locks.c */
 499 extern void locks_remove_posix(struct file *, fl_owner_t);
 500 extern void locks_remove_flock(struct file *);
 501 extern struct file_lock *posix_test_lock(struct file *, struct file_lock *);
 502 extern int posix_lock_file(struct file *, struct file_lock *, unsigned int);
 503 extern void posix_block_lock(struct file_lock *, struct file_lock *);
 504 extern void posix_unblock_lock(struct file_lock *);
 505
 506 struct fasync_struct {
 507         int     magic;
 508         int     fa_fd;
 509         struct  fasync_struct   *fa_next; /* singly linked list */
 510         struct  file            *fa_file;
 511 };
 512
 513 #define FASYNC_MAGIC 0x4601
 514
 515 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
 516
 517 #include <linux/minix_fs_sb.h>
 518 #include <linux/ext2_fs_sb.h>
 519 #include <linux/hpfs_fs_sb.h>
 520 #include <linux/ntfs_fs_sb.h>
 521 #include <linux/msdos_fs_sb.h>
 522 #include <linux/iso_fs_sb.h>
 523 #include <linux/nfs_fs_sb.h>
 524 #include <linux/sysv_fs_sb.h>
 525 #include <linux/affs_fs_sb.h>
 526 #include <linux/ufs_fs_sb.h>
 527 #include <linux/efs_fs_sb.h>
 528 #include <linux/romfs_fs_sb.h>
 529 #include <linux/smb_fs_sb.h>
 530 #include <linux/hfs_fs_sb.h>
 531 #include <linux/adfs_fs_sb.h>
 532 #include <linux/qnx4_fs_sb.h>
 533 #include <linux/bfs_fs_sb.h>
 534 #include <linux/udf_fs_sb.h>
 535 #include <linux/ncp_fs_sb.h>
 536
 537 extern struct list_head super_blocks;
 538
 539 #define sb_entry(list)  list_entry((list), struct super_block, s_list)
 540 struct super_block {
 541         struct list_head        s_list;         /* Keep this first */
 542         kdev_t                  s_dev;
 543         unsigned long           s_blocksize;
 544         unsigned char           s_blocksize_bits;
 545         unsigned char           s_lock;
 546         unsigned char           s_rd_only;
 547         unsigned char           s_dirt;
 548         struct file_system_type *s_type;
 549         struct super_operations *s_op;
 550         struct dquot_operations *dq_op;
 551         unsigned long           s_flags;
 552         unsigned long           s_magic;
 553         unsigned long           s_time;
 554         struct dentry           *s_root;
 555         wait_queue_head_t       s_wait;
 556
 557         struct inode            *s_ibasket;
 558         short int               s_ibasket_count;
 559         short int               s_ibasket_max;
 560         struct list_head        s_dirty;        /* dirty inodes */
 561         struct list_head        s_files;
 562
 563         union {
 564                 struct minix_sb_info    minix_sb;
 565                 struct ext2_sb_info     ext2_sb;
 566                 struct hpfs_sb_info     hpfs_sb;
 567                 struct ntfs_sb_info     ntfs_sb;
 568                 struct msdos_sb_info    msdos_sb;
 569                 struct isofs_sb_info    isofs_sb;
 570                 struct nfs_sb_info      nfs_sb;
 571                 struct sysv_sb_info     sysv_sb;
 572                 struct affs_sb_info     affs_sb;
 573                 struct ufs_sb_info      ufs_sb;
 574                 struct efs_sb_info      efs_sb;
 575                 struct romfs_sb_info    romfs_sb;
 576                 struct smb_sb_info      smbfs_sb;
 577                 struct hfs_sb_info      hfs_sb;
 578                 struct adfs_sb_info     adfs_sb;
 579                 struct qnx4_sb_info     qnx4_sb;
 580                 struct bfs_sb_info      bfs_sb;
 581                 struct udf_sb_info      udf_sb;
 582                 struct ncp_sb_info      ncpfs_sb;
 583                 void                    *generic_sbp;
 584         } u;
 585         /*
 586          * The next field is for VFS *only*. No filesystems have any business
 587          * even looking at it. You had been warned.
 588          */
 589         struct semaphore s_vfs_rename_sem;      /* Kludge */
 590 };
 591
 592 /*
 593  * VFS helper functions..
 594  */
 595 extern int vfs_rmdir(struct inode *, struct dentry *);
 596 extern int vfs_unlink(struct inode *, struct dentry *);
 597 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
 598
 599 /*
 600  * This is the "filldir" function type, used by readdir() to let
 601  * the kernel specify what kind of dirent layout it wants to have.
 602  * This allows the kernel to read directories into kernel space or
 603  * to have different dirent layouts depending on the binary type.
 604  */
 605 typedef int (*filldir_t)(void *, const char *, int, off_t, ino_t);
 606
 607 struct file_operations {
 608         loff_t (*llseek) (struct file *, loff_t, int);
 609         ssize_t (*read) (struct file *, char *, size_t, loff_t *);
 610         ssize_t (*write) (struct file *, const char *, size_t, loff_t *);
 611         int (*readdir) (struct file *, void *, filldir_t);
 612         unsigned int (*poll) (struct file *, struct poll_table_struct *);
 613         int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
 614         int (*mmap) (struct file *, struct vm_area_struct *);
 615         int (*open) (struct inode *, struct file *);
 616         int (*flush) (struct file *);
 617         int (*release) (struct inode *, struct file *);
 618         int (*fsync) (struct file *, struct dentry *);
 619         int (*fasync) (int, struct file *, int);
 620         int (*check_media_change) (kdev_t dev);
 621         int (*revalidate) (kdev_t dev);
 622         int (*lock) (struct file *, int, struct file_lock *);
 623 };
 624
 625 struct inode_operations {
 626         struct file_operations * default_file_ops;
 627         int (*create) (struct inode *,struct dentry *,int);
 628         struct dentry * (*lookup) (struct inode *,struct dentry *);
 629         int (*link) (struct dentry *,struct inode *,struct dentry *);
 630         int (*unlink) (struct inode *,struct dentry *);
 631         int (*symlink) (struct inode *,struct dentry *,const char *);
 632         int (*mkdir) (struct inode *,struct dentry *,int);
 633         int (*rmdir) (struct inode *,struct dentry *);
 634         int (*mknod) (struct inode *,struct dentry *,int,int);
 635         int (*rename) (struct inode *, struct dentry *,
 636                         struct inode *, struct dentry *);
 637         int (*readlink) (struct dentry *, char *,int);
 638         struct dentry * (*follow_link) (struct dentry *, struct dentry *, unsigned int);
 639         /*
 640          * the order of these functions within the VFS template has been
 641          * changed because SMP locking has changed: from now on all get_block,
 642          * readpage, writepage and flushpage functions are supposed to do
 643          * whatever locking they need to get proper SMP operation - for
 644          * now in most cases this means a lock/unlock_kernel at entry/exit.
 645          * [The new order is also slightly more logical :)]
 646          */
 647         /*
 648          * Generic block allocator exported by the lowlevel fs. All metadata
 649          * details are handled by the lowlevel fs, all 'logical data content'
 650          * details are handled by the highlevel block layer.
 651          */
 652         int (*get_block) (struct inode *, long, struct buffer_head *, int);
 653
 654         int (*readpage) (struct file *, struct page *);
 655         int (*writepage) (struct file *, struct page *);
 656         int (*flushpage) (struct inode *, struct page *, unsigned long);
 657
 658         void (*truncate) (struct inode *);
 659         int (*permission) (struct inode *, int);
 660         int (*smap) (struct inode *,int);
 661         int (*revalidate) (struct dentry *);
 662 };
 663
 664 struct super_operations {
 665         void (*read_inode) (struct inode *);
 666         void (*write_inode) (struct inode *);
 667         void (*put_inode) (struct inode *);
 668         void (*delete_inode) (struct inode *);
 669         int (*notify_change) (struct dentry *, struct iattr *);
 670         void (*put_super) (struct super_block *);
 671         void (*write_super) (struct super_block *);
 672         int (*statfs) (struct super_block *, struct statfs *, int);
 673         int (*remount_fs) (struct super_block *, int *, char *);
 674         void (*clear_inode) (struct inode *);
 675         void (*umount_begin) (struct super_block *);
 676 };
 677
 678 struct dquot_operations {
 679         void (*initialize) (struct inode *, short);
 680         void (*drop) (struct inode *);
 681         int (*alloc_block) (const struct inode *, unsigned long, uid_t, char);
 682         int (*alloc_inode) (const struct inode *, unsigned long, uid_t);
 683         void (*free_block) (const struct inode *, unsigned long);
 684         void (*free_inode) (const struct inode *, unsigned long);
 685         int (*transfer) (struct dentry *, struct iattr *, uid_t);
 686 };
 687
 688 struct file_system_type {
 689         const char *name;
 690         int fs_flags;
 691         struct super_block *(*read_super) (struct super_block *, void *, int);
 692         struct file_system_type * next;
 693 };
 694
 695 extern int register_filesystem(struct file_system_type *);
 696 extern int unregister_filesystem(struct file_system_type *);
 697
 698 /* Return value for VFS lock functions - tells locks.c to lock conventionally
 699  * REALLY kosha for root NFS and nfs_lock
 700  */
 701 #define LOCK_USE_CLNT 1
 702
 703 #define FLOCK_VERIFY_READ  1
 704 #define FLOCK_VERIFY_WRITE 2
 705
 706 extern int locks_mandatory_locked(struct inode *);
 707 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
 708
 709 /*
 710  * Candidates for mandatory locking have the setgid bit set
 711  * but no group execute bit -  an otherwise meaningless combination.
 712  */
 713 #define MANDATORY_LOCK(inode) \
 714         (IS_MANDLOCK(inode) && ((inode)->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
 715
 716 static inline int locks_verify_locked(struct inode *inode)
 717 {
 718         if (MANDATORY_LOCK(inode))
 719                 return locks_mandatory_locked(inode);
 720         return 0;
 721 }
 722
 723 extern inline int locks_verify_area(int read_write, struct inode *inode,
 724                                     struct file *filp, loff_t offset,
 725                                     size_t count)
 726 {
 727         if (inode->i_flock && MANDATORY_LOCK(inode))
 728                 return locks_mandatory_area(read_write, inode, filp, offset, count);
 729         return 0;
 730 }
 731
 732
 733 /* fs/open.c */
 734
 735 asmlinkage long sys_open(const char *, int, int);
 736 asmlinkage long sys_close(unsigned int);        /* yes, it's really unsigned */
 737 extern int do_close(unsigned int, int);         /* yes, it's really unsigned */
 738 extern int do_truncate(struct dentry *, unsigned long);
 739 extern int get_unused_fd(void);
 740 extern void put_unused_fd(unsigned int);
 741
 742 extern struct file *filp_open(const char *, int, int);
 743 extern int filp_close(struct file *, fl_owner_t id);
 744
 745 extern char * getname(const char *);
 746 #define __getname()     ((char *) __get_free_page(GFP_KERNEL))
 747 #define putname(name)   free_page((unsigned long)(name))
 748
 749 extern void kill_fasync(struct fasync_struct *, int, int);
 750 extern int register_blkdev(unsigned int, const char *, struct file_operations *);
 751 extern int unregister_blkdev(unsigned int, const char *);
 752 extern int blkdev_open(struct inode *, struct file *);
 753 extern int blkdev_release (struct inode *);
 754 extern struct file_operations def_blk_fops;
 755 extern struct inode_operations blkdev_inode_operations;
 756
 757 /* fs/devices.c */
 758 extern int register_chrdev(unsigned int, const char *, struct file_operations *);
 759 extern int unregister_chrdev(unsigned int, const char *);
 760 extern int chrdev_open(struct inode *, struct file *);
 761 extern struct file_operations def_chr_fops;
 762 extern struct inode_operations chrdev_inode_operations;
 763 extern char * bdevname(kdev_t);
 764 extern char * cdevname(kdev_t);
 765 extern char * kdevname(kdev_t);
 766 extern void init_special_inode(struct inode *, umode_t, int);
 767
 768 extern void init_fifo(struct inode *);
 769 extern struct inode_operations fifo_inode_operations;
 770
 771 /* Invalid inode operations -- fs/bad_inode.c */
 772 extern void make_bad_inode(struct inode *);
 773 extern int is_bad_inode(struct inode *);
 774
 775 extern struct file_operations connecting_fifo_fops;
 776 extern struct file_operations read_fifo_fops;
 777 extern struct file_operations write_fifo_fops;
 778 extern struct file_operations rdwr_fifo_fops;
 779 extern struct file_operations read_pipe_fops;
 780 extern struct file_operations write_pipe_fops;
 781 extern struct file_operations rdwr_pipe_fops;
 782
 783 extern struct file_system_type *get_fs_type(const char *);
 784
 785 extern int fs_may_remount_ro(struct super_block *);
 786 extern int fs_may_mount(kdev_t);
 787
 788 extern int try_to_free_buffers(struct page *);
 789 extern void refile_buffer(struct buffer_head * buf);
 790
 791 #define BUF_CLEAN       0
 792 #define BUF_LOCKED      1       /* Buffers scheduled for write */
 793 #define BUF_DIRTY       2       /* Dirty buffers, not yet scheduled for write */
 794 #define NR_LIST         3
 795
 796 /*
 797  * This is called by bh->b_end_io() handlers when I/O has completed.
 798  */
 799 extern inline void mark_buffer_uptodate(struct buffer_head * bh, int on)
 800 {
 801         if (on)
 802                 set_bit(BH_Uptodate, &bh->b_state);
 803         else
 804                 clear_bit(BH_Uptodate, &bh->b_state);
 805 }
 806
 807 #define atomic_set_buffer_clean(bh) test_and_clear_bit(BH_Dirty, &(bh)->b_state)
 808
 809 extern inline void __mark_buffer_clean(struct buffer_head *bh)
 810 {
 811         refile_buffer(bh);
 812 }
 813
 814 extern inline void mark_buffer_clean(struct buffer_head * bh)
 815 {
 816         if (atomic_set_buffer_clean(bh))
 817                 __mark_buffer_clean(bh);
 818 }
 819
 820 extern void FASTCALL(__mark_buffer_dirty(struct buffer_head *bh, int flag));
 821
 822 #define atomic_set_buffer_dirty(bh) test_and_set_bit(BH_Dirty, &(bh)->b_state)
 823
 824 extern inline void mark_buffer_dirty(struct buffer_head * bh, int flag)
 825 {
 826         if (!atomic_set_buffer_dirty(bh))
 827                 __mark_buffer_dirty(bh, flag);
 828 }
 829
 830 extern void balance_dirty(kdev_t);
 831 extern int check_disk_change(kdev_t);
 832 extern int invalidate_inodes(struct super_block *);
 833 extern void invalidate_inode_pages(struct inode *);
 834 extern void invalidate_buffers(kdev_t);
 835 extern int floppy_is_wp(int);
 836 extern void sync_inodes(kdev_t);
 837 extern void write_inode_now(struct inode *);
 838 extern void sync_dev(kdev_t);
 839 extern int fsync_dev(kdev_t);
 840 extern void sync_supers(kdev_t);
 841 extern int bmap(struct inode *, int);
 842 extern int notify_change(struct dentry *, struct iattr *);
 843 extern int permission(struct inode *, int);
 844 extern int get_write_access(struct inode *);
 845 extern void put_write_access(struct inode *);
 846 extern struct dentry * open_namei(const char *, int, int);
 847 extern struct dentry * do_mknod(const char *, int, dev_t);
 848 extern int do_pipe(int *);
 849
 850 /* fs/dcache.c -- generic fs support functions */
 851 extern int is_subdir(struct dentry *, struct dentry *);
 852 extern ino_t find_inode_number(struct dentry *, struct qstr *);
 853
 854 /*
 855  * Kernel pointers have redundant information, so we can use a
 856  * scheme where we can return either an error code or a dentry
 857  * pointer with the same return value.
 858  *
 859  * This should be a per-architecture thing, to allow different
 860  * error and pointer decisions.
 861  */
 862 #define ERR_PTR(err)    ((void *)((long)(err)))
 863 #define PTR_ERR(ptr)    ((long)(ptr))
 864 #define IS_ERR(ptr)     ((unsigned long)(ptr) > (unsigned long)(-1000))
 865
 866 /*
 867  * The bitmask for a lookup event:
 868  *  - follow links at the end
 869  *  - require a directory
 870  *  - ending slashes ok even for nonexistent files
 871  *  - internal "there are more path compnents" flag
 872  */
 873 #define LOOKUP_FOLLOW           (1)
 874 #define LOOKUP_DIRECTORY        (2)
 875 #define LOOKUP_SLASHOK          (4)
 876 #define LOOKUP_CONTINUE         (8)
 877
 878 /*
 879  * "descriptor" for what we're up to with a read for sendfile().
 880  * This allows us to use the same read code yet
 881  * have multiple different users of the data that
 882  * we read from a file.
 883  *
 884  * The simplest case just copies the data to user
 885  * mode.
 886  */
 887 typedef struct {
 888         size_t written;
 889         size_t count;
 890         char * buf;
 891         int error;
 892 } read_descriptor_t;
 893
 894 typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long);
 895
 896
 897 extern struct dentry * lookup_dentry(const char *, struct dentry *, unsigned int);
 898 extern struct dentry * __namei(const char *, unsigned int);
 899
 900 #define namei(pathname)         __namei(pathname, 1)
 901 #define lnamei(pathname)        __namei(pathname, 0)
 902
 903 extern void iput(struct inode *);
 904 extern struct inode * igrab(struct inode *);
 905 extern ino_t iunique(struct super_block *, ino_t);
 906
 907 typedef int (*find_inode_t)(struct inode *, unsigned long, void *);
 908 extern struct inode * iget4(struct super_block *, unsigned long, find_inode_t, void *);
 909 static inline struct inode *iget(struct super_block *sb, unsigned long ino)
 910 {
 911         return iget4(sb, ino, NULL, NULL);
 912 }
 913
 914 extern void clear_inode(struct inode *);
 915 extern struct inode * get_empty_inode(void);
 916
 917 extern void insert_inode_hash(struct inode *);
 918 extern void remove_inode_hash(struct inode *);
 919 extern struct file * get_empty_filp(void);
 920 extern void file_move(struct file *f, struct list_head *list);
 921 extern void file_moveto(struct file *new, struct file *old);
 922 extern struct buffer_head * get_hash_table(kdev_t, int, int);
 923 extern struct buffer_head * getblk(kdev_t, int, int);
 924 extern void ll_rw_block(int, int, struct buffer_head * bh[]);
 925 extern int is_read_only(kdev_t);
 926 extern void __brelse(struct buffer_head *);
 927 extern inline void brelse(struct buffer_head *buf)
 928 {
 929         if (buf)
 930                 __brelse(buf);
 931 }
 932 extern void __bforget(struct buffer_head *);
 933 extern inline void bforget(struct buffer_head *buf)
 934 {
 935         if (buf)
 936                 __bforget(buf);
 937 }
 938 extern void set_blocksize(kdev_t, int);
 939 extern unsigned int get_hardblocksize(kdev_t);
 940 extern struct buffer_head * bread(kdev_t, int, int);
 941 extern struct buffer_head * breada(kdev_t, int, int, unsigned int, unsigned int);
 942 extern void wakeup_bdflush(int wait);
 943
 944 extern int brw_page(int, struct page *, kdev_t, int [], int);
 945
 946 typedef int (*writepage_t)(struct file *, struct page *, unsigned long, unsigned long, const char *);
 947
 948 /* Generic buffer handling for block filesystems.. */
 949 extern int block_read_full_page(struct file *, struct page *);
 950 extern int block_write_full_page (struct file *, struct page *);
 951 extern int block_write_partial_page (struct file *, struct page *, unsigned long, unsigned long, const char *);
 952 extern int block_write_cont_page (struct file *, struct page *, unsigned long, unsigned long, const char *);
 953 extern int block_flushpage(struct inode *, struct page *, unsigned long);
 954
 955 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
 956 extern ssize_t generic_file_read(struct file *, char *, size_t, loff_t *);
 957 extern ssize_t generic_file_write(struct file *, const char *, size_t, loff_t *, writepage_t);
 958 extern void do_generic_file_read(struct file * filp, loff_t *ppos, read_descriptor_t * desc, read_actor_t actor);
 959
 960
 961 extern struct super_block *get_super(kdev_t);
 962 struct super_block *get_empty_super(void);
 963 void remove_vfsmnt(kdev_t dev);
 964 extern void put_super(kdev_t);
 965 unsigned long generate_cluster(kdev_t, int b[], int);
 966 unsigned long generate_cluster_swab32(kdev_t, int b[], int);
 967 extern kdev_t ROOT_DEV;
 968
 969 extern void show_buffers(void);
 970 extern void mount_root(void);
 971
 972 #ifdef CONFIG_BLK_DEV_INITRD
 973 extern kdev_t real_root_dev;
 974 extern int change_root(kdev_t, const char *);
 975 #endif
 976
 977 extern ssize_t char_read(struct file *, char *, size_t, loff_t *);
 978 extern ssize_t block_read(struct file *, char *, size_t, loff_t *);
 979 extern int read_ahead[];
 980
 981 extern ssize_t char_write(struct file *, const char *, size_t, loff_t *);
 982 extern ssize_t block_write(struct file *, const char *, size_t, loff_t *);
 983
 984 extern int block_fsync(struct file *, struct dentry *);
 985 extern int file_fsync(struct file *, struct dentry *);
 986 extern int generic_buffer_fdatasync(struct inode *inode, unsigned long start, unsigned long end);
 987
 988 extern int inode_change_ok(struct inode *, struct iattr *);
 989 extern void inode_setattr(struct inode *, struct iattr *);
 990
 991 #endif /* __KERNEL__ */
 992
 993 #endif /* _LINUX_FS_H */