Merge with Linux 2.5.48.

[linux-2.6/linux-mips.git] / include / linux / fs.h

#ifndef _LINUX_FS_H
#define _LINUX_FS_H

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

#include <linux/config.h>
#include <linux/linkage.h>
#include <linux/limits.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <linux/vfs.h>
#include <linux/kdev_t.h>
#include <linux/ioctl.h>
#include <linux/list.h>
#include <linux/dcache.h>
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/radix-tree.h>
#include <asm/atomic.h>

struct iovec;
struct nameidata;
struct pipe_inode_info;
struct poll_table_struct;
struct vm_area_struct;
struct vfsmount;

/*
 * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
 * the file limit at runtime and only root can increase the per-process
 * nr_file rlimit, so it's safe to set up a ridiculously high absolute
 * upper limit on files-per-process.
 *
 * Some programs (notably those using select()) may have to be 
 * recompiled to take full advantage of the new limits..  
 */

/* Fixed constants first: */
#undef NR_OPEN
#define NR_OPEN (1024*1024)     /* Absolute upper limit on fd num */
#define INR_OPEN 1024           /* Initial setting for nfile rlimits */

#define BLOCK_SIZE_BITS 10
#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)

/* And dynamically-tunable limits and defaults: */
struct files_stat_struct {
        int nr_files;           /* read only */
        int nr_free_files;      /* read only */
        int max_files;          /* tunable */
};
extern struct files_stat_struct files_stat;

struct inodes_stat_t {
        int nr_inodes;
        int nr_unused;
        int dummy[5];
};
extern struct inodes_stat_t inodes_stat;

extern int leases_enable, dir_notify_enable, lease_break_time;

#define NR_FILE  8192   /* this can well be larger on a larger system */
#define NR_RESERVED_FILES 10 /* reserved for root */
#define NR_SUPER 256

#define MAY_EXEC 1
#define MAY_WRITE 2
#define MAY_READ 4
#define MAY_APPEND 8

#define FMODE_READ 1
#define FMODE_WRITE 2

#define RW_MASK         1
#define RWA_MASK        2
#define READ 0
#define WRITE 1
#define READA 2         /* read-ahead  - don't block if no resources */
#define SPECIAL 4       /* For non-blockdevice requests in request queue */

#define SEL_IN          1
#define SEL_OUT         2
#define SEL_EX          4

/* public flags for file_system_type */
#define FS_REQUIRES_DEV 1 
#define FS_ODD_RENAME   32768   /* Temporary stuff; will go away as soon
                                  * as nfs_rename() will be cleaned up
                                  */
/*
 * These are the fs-independent mount-flags: up to 32 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 MS_DIRSYNC      128     /* Directory modifications are synchronous */
#define MS_NOATIME      1024    /* Do not update access times. */
#define MS_NODIRATIME   2048    /* Do not update directory access times */
#define MS_BIND         4096
#define MS_MOVE         8192
#define MS_REC          16384
#define MS_VERBOSE      32768
#define MS_POSIXACL     (1<<16) /* VFS does not apply the umask */
#define MS_ACTIVE       (1<<30)
#define MS_NOUSER       (1<<31)

/*
 * Superblock flags that can be altered by MS_REMOUNT
 */
#define MS_RMT_MASK     (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_NOATIME|\
                         MS_NODIRATIME)

/*
 * Old magic mount flag and mask
 */
#define MS_MGC_VAL 0xC0ED0000
#define MS_MGC_MSK 0xffff0000

/* Inode flags - they have nothing to superblock flags now */

#define S_SYNC          1       /* Writes are synced at once */
#define S_NOATIME       2       /* Do not update access times */
#define S_QUOTA         4       /* Quota initialized for file */
#define S_APPEND        8       /* Append-only file */
#define S_IMMUTABLE     16      /* Immutable file */
#define S_DEAD          32      /* removed, but still open directory */
#define S_NOQUOTA       64      /* Inode is not counted to quota */
#define S_DIRSYNC       128     /* Directory modifications are synchronous */

/*
 * Note that nosuid 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.
 *
 * Unfortunately, it is possible to change a filesystems flags with it mounted
 * with files in use.  This means that all of the inodes will not have their
 * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
 * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
 */
#define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))

#define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
#define IS_SYNC(inode)          (__IS_FLG(inode, MS_SYNCHRONOUS) || \
                                        ((inode)->i_flags & S_SYNC))
#define IS_DIRSYNC(inode)       (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
                                        ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
#define IS_MANDLOCK(inode)      __IS_FLG(inode, MS_MANDLOCK)

#define IS_QUOTAINIT(inode)     ((inode)->i_flags & S_QUOTA)
#define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
#define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
#define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
#define IS_NOATIME(inode)       (__IS_FLG(inode, MS_NOATIME) || ((inode)->i_flags & S_NOATIME))
#define IS_NODIRATIME(inode)    __IS_FLG(inode, MS_NODIRATIME)
#define IS_POSIXACL(inode)      __IS_FLG(inode, MS_POSIXACL)

#define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)

/* the read-only stuff doesn't really belong here, but any other place is
   probably as bad and I don't want to create yet another include file. */

#define BLKROSET   _IO(0x12,93) /* set device read-only (0 = read-write) */
#define BLKROGET   _IO(0x12,94) /* get read-only status (0 = read_write) */
#define BLKRRPART  _IO(0x12,95) /* re-read partition table */
#define BLKGETSIZE _IO(0x12,96) /* return device size /512 (long *arg) */
#define BLKFLSBUF  _IO(0x12,97) /* flush buffer cache */
#define BLKRASET   _IO(0x12,98) /* set read ahead for block device */
#define BLKRAGET   _IO(0x12,99) /* get current read ahead setting */
#define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
#define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
#define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
#if 0
#define BLKPG      _IO(0x12,105)/* See blkpg.h */
#define BLKELVGET  _IOR(0x12,106,sizeof(blkelv_ioctl_arg_t))/* elevator get */
#define BLKELVSET  _IOW(0x12,107,sizeof(blkelv_ioctl_arg_t))/* elevator set */
/* This was here just to show that the number is taken -
   probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
#endif
/* A jump here: 108-111 have been used for various private purposes. */
#define BLKBSZGET  _IOR(0x12,112,sizeof(int))
#define BLKBSZSET  _IOW(0x12,113,sizeof(int))
#define BLKGETSIZE64 _IOR(0x12,114,sizeof(u64)) /* return device size in bytes (u64 *arg) */

#define BMAP_IOCTL 1            /* obsolete - kept for compatibility */
#define FIBMAP     _IO(0x00,1)  /* bmap access */
#define FIGETBSZ   _IO(0x00,2)  /* get the block size used for bmap */

#ifdef __KERNEL__

#include <asm/semaphore.h>
#include <asm/byteorder.h>

extern void update_atime (struct inode *);
#define UPDATE_ATIME(inode) update_atime (inode)

extern void inode_init(unsigned long);
extern void mnt_init(unsigned long);
extern void files_init(unsigned long);

struct buffer_head;
typedef int (get_block_t)(struct inode *inode, sector_t iblock,
                        struct buffer_head *bh_result, int create);
typedef int (get_blocks_t)(struct inode *inode, sector_t iblock,
                        unsigned long max_blocks,
                        struct buffer_head *bh_result, int create);

/*
 * Attribute flags.  These should be or-ed together to figure out what
 * has been changed!
 */
#define ATTR_MODE       1
#define ATTR_UID        2
#define ATTR_GID        4
#define ATTR_SIZE       8
#define ATTR_ATIME      16
#define ATTR_MTIME      32
#define ATTR_CTIME      64
#define ATTR_ATIME_SET  128
#define ATTR_MTIME_SET  256
#define ATTR_FORCE      512     /* Not a change, but a change it */
#define ATTR_ATTR_FLAG  1024
#define ATTR_KILL_SUID  2048
#define ATTR_KILL_SGID  4096

/*
 * This is the Inode Attributes structure, used for notify_change().  It
 * uses the above definitions as flags, to know which values have changed.
 * Also, in this manner, a Filesystem can look at only the values it cares
 * about.  Basically, these are the attributes that the VFS layer can
 * request to change from the FS layer.
 *
 * Derek Atkins <warlord@MIT.EDU> 94-10-20
 */
struct iattr {
        unsigned int    ia_valid;
        umode_t         ia_mode;
        uid_t           ia_uid;
        gid_t           ia_gid;
        loff_t          ia_size;
        struct timespec ia_atime;
        struct timespec ia_mtime;
        struct timespec ia_ctime;
        unsigned int    ia_attr_flags;
};

/*
 * This is the inode attributes flag definitions
 */
#define ATTR_FLAG_SYNCRONOUS    1       /* Syncronous write */
#define ATTR_FLAG_NOATIME       2       /* Don't update atime */
#define ATTR_FLAG_APPEND        4       /* Append-only file */
#define ATTR_FLAG_IMMUTABLE     8       /* Immutable file */
#define ATTR_FLAG_NODIRATIME    16      /* Don't update atime for directory */

/*
 * Includes for diskquotas.
 */
#include <linux/quota.h>

/*
 * oh the beauties of C type declarations.
 */
struct page;
struct address_space;
struct writeback_control;

struct address_space_operations {
        int (*writepage)(struct page *);
        int (*readpage)(struct file *, struct page *);
        int (*sync_page)(struct page *);

        /* Write back some dirty pages from this mapping. */
        int (*writepages)(struct address_space *, struct writeback_control *);

        /* Perform a writeback as a memory-freeing operation. */
        int (*vm_writeback)(struct page *, struct writeback_control *);

        /* Set a page dirty */
        int (*set_page_dirty)(struct page *page);

        int (*readpages)(struct file *filp, struct address_space *mapping,
                        struct list_head *pages, unsigned nr_pages);

        /*
         * ext3 requires that a successful prepare_write() call be followed
         * by a commit_write() call - they must be balanced
         */
        int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
        int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
        /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
        sector_t (*bmap)(struct address_space *, sector_t);
        int (*invalidatepage) (struct page *, unsigned long);
        int (*releasepage) (struct page *, int);
        int (*direct_IO)(int, struct file *, const struct iovec *iov,
                        loff_t offset, unsigned long nr_segs);
};

struct backing_dev_info;
struct address_space {
        struct inode            *host;          /* owner: inode, block_device */
        struct radix_tree_root  page_tree;      /* radix tree of all pages */
        rwlock_t                page_lock;      /* and rwlock protecting it */
        struct list_head        clean_pages;    /* list of clean pages */
        struct list_head        dirty_pages;    /* list of dirty pages */
        struct list_head        locked_pages;   /* list of locked pages */
        struct list_head        io_pages;       /* being prepared for I/O */
        unsigned long           nrpages;        /* number of total pages */
        struct address_space_operations *a_ops; /* methods */
        struct list_head        i_mmap;         /* list of private mappings */
        struct list_head        i_mmap_shared;  /* list of private mappings */
        spinlock_t              i_shared_lock;  /* and spinlock protecting it */
        unsigned long           dirtied_when;   /* jiffies of first page dirtying */
        int                     gfp_mask;       /* how to allocate the pages */
        struct backing_dev_info *backing_dev_info; /* device readahead, etc */
        spinlock_t              private_lock;   /* for use by the address_space */
        struct list_head        private_list;   /* ditto */
        struct address_space    *assoc_mapping; /* ditto */
};

struct char_device {
        struct list_head        hash;
        atomic_t                count;
        dev_t                   dev;
        atomic_t                openers;
        struct semaphore        sem;
};

struct block_device {
        struct list_head        bd_hash;
        atomic_t                bd_count;
        struct inode *          bd_inode;
        dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
        int                     bd_openers;
        struct semaphore        bd_sem; /* open/close mutex */
        struct list_head        bd_inodes;
        void *                  bd_holder;
        int                     bd_holders;
        struct block_device *   bd_contains;
        unsigned                bd_block_size;
        sector_t                bd_offset;
        unsigned                bd_part_count;
        int                     bd_invalidated;
        struct gendisk *        bd_disk;
};

struct inode {
        struct list_head        i_hash;
        struct list_head        i_list;
        struct list_head        i_dentry;
        unsigned long           i_ino;
        atomic_t                i_count;
        dev_t                   i_dev;
        umode_t                 i_mode;
        unsigned int            i_nlink;
        uid_t                   i_uid;
        gid_t                   i_gid;
        kdev_t                  i_rdev;
        loff_t                  i_size;
        struct timespec         i_atime;
        struct timespec         i_mtime;
        struct timespec         i_ctime;
        unsigned int            i_blkbits;
        unsigned long           i_blksize;
        unsigned long           i_blocks;
        unsigned long           i_version;
        unsigned short          i_bytes;
        struct semaphore        i_sem;
        struct inode_operations *i_op;
        struct file_operations  *i_fop; /* former ->i_op->default_file_ops */
        struct super_block      *i_sb;
        struct file_lock        *i_flock;
        struct address_space    *i_mapping;
        struct address_space    i_data;
        struct dquot            *i_dquot[MAXQUOTAS];
        /* These three should probably be a union */
        struct list_head        i_devices;
        struct pipe_inode_info  *i_pipe;
        struct block_device     *i_bdev;
        struct char_device      *i_cdev;

        unsigned long           i_dnotify_mask; /* Directory notify events */
        struct dnotify_struct   *i_dnotify; /* for directory notifications */

        unsigned long           i_state;

        unsigned int            i_flags;
        unsigned char           i_sock;

        atomic_t                i_writecount;
        void                    *i_security;
        __u32                   i_generation;
        union {
                void                            *generic_ip;
        } u;
};

/* will die */
#include <linux/coda_fs_i.h>

struct fown_struct {
        rwlock_t lock;          /* protects pid, uid, euid fields */
        int pid;                /* pid or -pgrp where SIGIO should be sent */
        uid_t uid, euid;        /* uid/euid of process setting the owner */
        int signum;             /* posix.1b rt signal to be delivered on IO */
        void *security;
};

static inline void inode_add_bytes(struct inode *inode, loff_t bytes)
{
        inode->i_blocks += bytes >> 9;
        bytes &= 511;
        inode->i_bytes += bytes;
        if (inode->i_bytes >= 512) {
                inode->i_blocks++;
                inode->i_bytes -= 512;
        }
}

static inline void inode_sub_bytes(struct inode *inode, loff_t bytes)
{
        inode->i_blocks -= bytes >> 9;
        bytes &= 511;
        if (inode->i_bytes < bytes) {
                inode->i_blocks--;
                inode->i_bytes += 512;
        }
        inode->i_bytes -= bytes;
}

static inline loff_t inode_get_bytes(struct inode *inode)
{
        return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
}

static inline void inode_set_bytes(struct inode *inode, loff_t bytes)
{
        inode->i_blocks = bytes >> 9;
        inode->i_bytes = bytes & 511;
}

/*
 * Track a single file's readahead state
 */
struct file_ra_state {
        unsigned long start;            /* Current window */
        unsigned long size;
        unsigned long next_size;        /* Next window size */
        unsigned long prev_page;        /* Cache last read() position */
        unsigned long ahead_start;      /* Ahead window */
        unsigned long ahead_size;
        unsigned long ra_pages;         /* Maximum readahead window */
};

struct file {
        struct list_head        f_list;
        struct dentry           *f_dentry;
        struct vfsmount         *f_vfsmnt;
        struct file_operations  *f_op;
        atomic_t                f_count;
        unsigned int            f_flags;
        mode_t                  f_mode;
        loff_t                  f_pos;
        struct fown_struct      f_owner;
        unsigned int            f_uid, f_gid;
        int                     f_error;
        struct file_ra_state    f_ra;

        unsigned long           f_version;
        void                    *f_security;

        /* needed for tty driver, and maybe others */
        void                    *private_data;

        /* Used by fs/eventpoll.c to link all the hooks to this file */
        struct list_head        f_ep_links;
        spinlock_t              f_ep_lock;
};
extern spinlock_t files_lock;
#define file_list_lock() spin_lock(&files_lock);
#define file_list_unlock() spin_unlock(&files_lock);

#define get_file(x)     atomic_inc(&(x)->f_count)
#define file_count(x)   atomic_read(&(x)->f_count)

extern int init_private_file(struct file *, struct dentry *, int);

#define MAX_NON_LFS     ((1UL<<31) - 1)

/* Page cache limit. The filesystems should put that into their s_maxbytes 
   limits, otherwise bad things can happen in VM. */ 
#if BITS_PER_LONG==32
#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
#elif BITS_PER_LONG==64
#define MAX_LFS_FILESIZE        0x7fffffffffffffff
#endif

#define FL_POSIX        1
#define FL_FLOCK        2
#define FL_ACCESS       8       /* not trying to lock, just looking */
#define FL_LOCKD        16      /* lock held by rpc.lockd */
#define FL_LEASE        32      /* lease held on this file */
#define FL_SLEEP        128     /* A blocking lock */

/*
 * The POSIX file lock owner is determined by
 * the "struct files_struct" in the thread group
 * (or NULL for no owner - BSD locks).
 *
 * Lockd stuffs a "host" pointer into this.
 */
typedef struct files_struct *fl_owner_t;

/* that will die - we need it for nfs_lock_info */
#include <linux/nfs_fs_i.h>

struct file_lock {
        struct file_lock *fl_next;      /* singly linked list for this inode  */
        struct list_head fl_link;       /* doubly linked list of all locks */
        struct list_head fl_block;      /* circular list of blocked processes */
        fl_owner_t fl_owner;
        unsigned int fl_pid;
        wait_queue_head_t fl_wait;
        struct file *fl_file;
        unsigned char fl_flags;
        unsigned char fl_type;
        loff_t fl_start;
        loff_t fl_end;

        void (*fl_notify)(struct file_lock *);  /* unblock callback */
        void (*fl_insert)(struct file_lock *);  /* lock insertion callback */
        void (*fl_remove)(struct file_lock *);  /* lock removal callback */

        struct fasync_struct *  fl_fasync; /* for lease break notifications */
        unsigned long fl_break_time;    /* for nonblocking lease breaks */

        union {
                struct nfs_lock_info    nfs_fl;
        } fl_u;
};

/* The following constant reflects the upper bound of the file/locking space */
#ifndef OFFSET_MAX
#define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
#define OFFSET_MAX      INT_LIMIT(loff_t)
#define OFFT_OFFSET_MAX INT_LIMIT(off_t)
#endif

extern struct list_head file_lock_list;

#include <linux/fcntl.h>

extern int fcntl_getlk(struct file *, struct flock *);
extern int fcntl_setlk(struct file *, unsigned int, struct flock *);

extern int fcntl_getlk64(struct file *, struct flock64 *);
extern int fcntl_setlk64(struct file *, unsigned int, struct flock64 *);

/* fs/locks.c */
extern void locks_init_lock(struct file_lock *);
extern void locks_copy_lock(struct file_lock *, struct file_lock *);
extern void locks_remove_posix(struct file *, fl_owner_t);
extern void locks_remove_flock(struct file *);
extern struct file_lock *posix_test_lock(struct file *, struct file_lock *);
extern int posix_lock_file(struct file *, struct file_lock *);
extern void posix_block_lock(struct file_lock *, struct file_lock *);
extern void posix_unblock_lock(struct file *, struct file_lock *);
extern int posix_locks_deadlock(struct file_lock *, struct file_lock *);
extern int __get_lease(struct inode *inode, unsigned int flags);
extern void lease_get_mtime(struct inode *, struct timespec *time);
extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
extern int lock_may_write(struct inode *, loff_t start, unsigned long count);

struct fasync_struct {
        int     magic;
        int     fa_fd;
        struct  fasync_struct   *fa_next; /* singly linked list */
        struct  file            *fa_file;
};

#define FASYNC_MAGIC 0x4601

/* SMP safe fasync helpers: */
extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
/* can be called from interrupts */
extern void kill_fasync(struct fasync_struct **, int, int);
/* only for net: no internal synchronization */
extern void __kill_fasync(struct fasync_struct *, int, int);

extern int f_setown(struct file *filp, unsigned long arg, int force);
extern void f_delown(struct file *filp);
extern int send_sigurg(struct fown_struct *fown);

/*
 *      Umount options
 */

#define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
#define MNT_DETACH      0x00000002      /* Just detach from the tree */

extern struct list_head super_blocks;
extern spinlock_t sb_lock;

#define sb_entry(list)  list_entry((list), struct super_block, s_list)
#define S_BIAS (1<<30)
struct super_block {
        struct list_head        s_list;         /* Keep this first */
        dev_t                   s_dev;          /* search index; _not_ kdev_t */
        unsigned long           s_blocksize;
        unsigned long           s_old_blocksize;
        unsigned char           s_blocksize_bits;
        unsigned char           s_dirt;
        unsigned long long      s_maxbytes;     /* Max file size */
        struct file_system_type *s_type;
        struct super_operations *s_op;
        struct dquot_operations *dq_op;
        struct quotactl_ops     *s_qcop;
        struct export_operations *s_export_op;
        unsigned long           s_flags;
        unsigned long           s_magic;
        struct dentry           *s_root;
        struct rw_semaphore     s_umount;
        struct semaphore        s_lock;
        int                     s_count;
        int                     s_syncing;
        atomic_t                s_active;
        void                    *s_security;

        struct list_head        s_dirty;        /* dirty inodes */
        struct list_head        s_io;           /* parked for writeback */
        struct list_head        s_anon;         /* anonymous dentries for (nfs) exporting */
        struct list_head        s_files;

        struct block_device     *s_bdev;
        struct list_head        s_instances;
        struct quota_info       s_dquot;        /* Diskquota specific options */

        char s_id[32];                          /* Informational name */

        void                    *s_fs_info;     /* Filesystem private info */

        /*
         * The next field is for VFS *only*. No filesystems have any business
         * even looking at it. You had been warned.
         */
        struct semaphore s_vfs_rename_sem;      /* Kludge */
};

/*
 * Superblock locking.
 */
static inline void lock_super(struct super_block * sb)
{
        down(&sb->s_lock);
}

static inline void unlock_super(struct super_block * sb)
{
        up(&sb->s_lock);
}

/*
 * VFS helper functions..
 */
extern int vfs_create(struct inode *, struct dentry *, int);
extern int vfs_mkdir(struct inode *, struct dentry *, int);
extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t);
extern int vfs_symlink(struct inode *, struct dentry *, const char *);
extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);

/*
 * File types
 *
 * NOTE! These match bits 12..15 of stat.st_mode
 * (ie "(i_mode >> 12) & 15").
 */
#define DT_UNKNOWN      0
#define DT_FIFO         1
#define DT_CHR          2
#define DT_DIR          4
#define DT_BLK          6
#define DT_REG          8
#define DT_LNK          10
#define DT_SOCK         12
#define DT_WHT          14

/*
 * This is the "filldir" function type, used by readdir() to let
 * the kernel specify what kind of dirent layout it wants to have.
 * This allows the kernel to read directories into kernel space or
 * to have different dirent layouts depending on the binary type.
 */
typedef int (*filldir_t)(void *, const char *, int, loff_t, ino_t, unsigned);

struct block_device_operations {
        int (*open) (struct inode *, struct file *);
        int (*release) (struct inode *, struct file *);
        int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long);
        int (*media_changed) (struct gendisk *);
        int (*revalidate_disk) (struct gendisk *);
        struct module *owner;
};

/*
 * "descriptor" for what we're up to with a read for sendfile().
 * This allows us to use the same read code yet
 * have multiple different users of the data that
 * we read from a file.
 *
 * The simplest case just copies the data to user
 * mode.
 */
typedef struct {
        size_t written;
        size_t count;
        char * buf;
        int error;
} read_descriptor_t;

typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long);

/*
 * NOTE:
 * read, write, poll, fsync, readv, writev can be called
 *   without the big kernel lock held in all filesystems.
 */
struct kiocb;
struct file_operations {
        struct module *owner;
        loff_t (*llseek) (struct file *, loff_t, int);
        ssize_t (*read) (struct file *, char *, size_t, loff_t *);
        ssize_t (*aio_read) (struct kiocb *, char *, size_t, loff_t);
        ssize_t (*write) (struct file *, const char *, size_t, loff_t *);
        ssize_t (*aio_write) (struct kiocb *, const char *, size_t, loff_t);
        int (*readdir) (struct file *, void *, filldir_t);
        unsigned int (*poll) (struct file *, struct poll_table_struct *);
        int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
        int (*mmap) (struct file *, struct vm_area_struct *);
        int (*open) (struct inode *, struct file *);
        int (*flush) (struct file *);
        int (*release) (struct inode *, struct file *);
        int (*fsync) (struct file *, struct dentry *, int datasync);
        int (*aio_fsync) (struct kiocb *, int datasync);
        int (*fasync) (int, struct file *, int);
        int (*lock) (struct file *, int, struct file_lock *);
        ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *);
        ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *);
        ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *);
        ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
        unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
};

struct inode_operations {
        int (*create) (struct inode *,struct dentry *,int);
        struct dentry * (*lookup) (struct inode *,struct dentry *);
        int (*link) (struct dentry *,struct inode *,struct dentry *);
        int (*unlink) (struct inode *,struct dentry *);
        int (*symlink) (struct inode *,struct dentry *,const char *);
        int (*mkdir) (struct inode *,struct dentry *,int);
        int (*rmdir) (struct inode *,struct dentry *);
        int (*mknod) (struct inode *,struct dentry *,int,int);
        int (*rename) (struct inode *, struct dentry *,
                        struct inode *, struct dentry *);
        int (*readlink) (struct dentry *, char *,int);
        int (*follow_link) (struct dentry *, struct nameidata *);
        void (*truncate) (struct inode *);
        int (*permission) (struct inode *, int);
        int (*setattr) (struct dentry *, struct iattr *);
        int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
        int (*setxattr) (struct dentry *, const char *, void *, size_t, int);
        ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
        ssize_t (*listxattr) (struct dentry *, char *, size_t);
        int (*removexattr) (struct dentry *, const char *);
};

struct seq_file;

extern ssize_t vfs_read(struct file *, char *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec *,
                unsigned long, loff_t *);
extern ssize_t vfs_writev(struct file *, const struct iovec *,
                unsigned long, loff_t *);

/*
 * NOTE: write_inode, delete_inode, clear_inode, put_inode can be called
 * without the big kernel lock held in all filesystems.
 */
struct super_operations {
        struct inode *(*alloc_inode)(struct super_block *sb);
        void (*destroy_inode)(struct inode *);

        void (*read_inode) (struct inode *);
  
        void (*dirty_inode) (struct inode *);
        void (*write_inode) (struct inode *, int);
        void (*put_inode) (struct inode *);
        void (*drop_inode) (struct inode *);
        void (*delete_inode) (struct inode *);
        void (*put_super) (struct super_block *);
        void (*write_super) (struct super_block *);
        void (*write_super_lockfs) (struct super_block *);
        void (*unlockfs) (struct super_block *);
        int (*statfs) (struct super_block *, struct statfs *);
        int (*remount_fs) (struct super_block *, int *, char *);
        void (*clear_inode) (struct inode *);
        void (*umount_begin) (struct super_block *);

        int (*show_options)(struct seq_file *, struct vfsmount *);
};

/* Inode state bits.  Protected by inode_lock. */
#define I_DIRTY_SYNC            1 /* Not dirty enough for O_DATASYNC */
#define I_DIRTY_DATASYNC        2 /* Data-related inode changes pending */
#define I_DIRTY_PAGES           4 /* Data-related inode changes pending */
#define I_LOCK                  8
#define I_FREEING               16
#define I_CLEAR                 32
#define I_NEW                   64

#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)

extern void __mark_inode_dirty(struct inode *, int);
static inline void mark_inode_dirty(struct inode *inode)
{
        __mark_inode_dirty(inode, I_DIRTY);
}

static inline void mark_inode_dirty_sync(struct inode *inode)
{
        __mark_inode_dirty(inode, I_DIRTY_SYNC);
}


/**
 * &export_operations - for nfsd to communicate with file systems
 * decode_fh:      decode a file handle fragment and return a &struct dentry
 * encode_fh:      encode a file handle fragment from a dentry
 * get_name:       find the name for a given inode in a given directory
 * get_parent:     find the parent of a given directory
 * get_dentry:     find a dentry for the inode given a file handle sub-fragment
 *
 * Description:
 *    The export_operations structure provides a means for nfsd to communicate
 *    with a particular exported file system  - particularly enabling nfsd and
 *    the filesystem to co-operate when dealing with file handles.
 *
 *    export_operations contains two basic operation for dealing with file handles,
 *    decode_fh() and encode_fh(), and allows for some other operations to be defined
 *    which standard helper routines use to get specific information from the
 *    filesystem.
 *
 *    nfsd encodes information use to determine which filesystem a filehandle
 *    applies to in the initial part of the file handle.  The remainder, termed a
 *    file handle fragment, is controlled completely by the filesystem.
 *    The standard helper routines assume that this fragment will contain one or two
 *    sub-fragments, one which identifies the file, and one which may be used to
 *    identify the (a) directory containing the file.
 *
 *    In some situations, nfsd needs to get a dentry which is connected into a
 *    specific part of the file tree.  To allow for this, it passes the function
 *    acceptable() together with a @context which can be used to see if the dentry
 *    is acceptable.  As there can be multiple dentrys for a given file, the filesystem
 *    should check each one for acceptability before looking for the next.  As soon
 *    as an acceptable one is found, it should be returned.
 *
 * decode_fh:
 *    @decode_fh is given a &struct super_block (@sb), a file handle fragment (@fh, @fh_len)
 *    and an acceptability testing function (@acceptable, @context).  It should return
 *    a &struct dentry which refers to the same file that the file handle fragment refers
 *    to,  and which passes the acceptability test.  If it cannot, it should return
 *    a %NULL pointer if the file was found but no acceptable &dentries were available, or
 *    a %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or %ENOMEM).
 *
 * encode_fh:
 *    @encode_fh should store in the file handle fragment @fh (using at most @max_len bytes)
 *    information that can be used by @decode_fh to recover the file refered to by the
 *    &struct dentry @de.  If the @connectable flag is set, the encode_fh() should store
 *    sufficient information so that a good attempt can be made to find not only
 *    the file but also it's place in the filesystem.   This typically means storing
 *    a reference to de->d_parent in the filehandle fragment.
 *    encode_fh() should return the number of bytes stored or a negative error code
 *    such as %-ENOSPC
 *
 * get_name:
 *    @get_name should find a name for the given @child in the given @parent directory.
 *    The name should be stored in the @name (with the understanding that it is already
 *    pointing to a a %NAME_MAX+1 sized buffer.   get_name() should return %0 on success,
 *    a negative error code or error.
 *    @get_name will be called without @parent->i_sem held.
 *
 * get_parent:
 *    @get_parent should find the parent directory for the given @child which is also
 *    a directory.  In the event that it cannot be found, or storage space cannot be
 *    allocated, a %ERR_PTR should be returned.
 *
 * get_dentry:
 *    Given a &super_block (@sb) and a pointer to a file-system specific inode identifier,
 *    possibly an inode number, (@inump) get_dentry() should find the identified inode and
 *    return a dentry for that inode.
 *    Any suitable dentry can be returned including, if necessary, a new dentry created
 *    with d_alloc_root.  The caller can then find any other extant dentrys by following the
 *    d_alias links.  If a new dentry was created using d_alloc_root, DCACHE_NFSD_DISCONNECTED
 *    should be set, and the dentry should be d_rehash()ed.
 *
 *    If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code can be returned.
 *    The @inump will be whatever was passed to nfsd_find_fh_dentry() in either the
 *    @obj or @parent parameters.
 *
 * Locking rules:
 *  get_parent is called with child->d_inode->i_sem down
 *  get_name is not (which is possibly inconsistent)
 */

struct export_operations {
        struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh, int fh_len, int fh_type,
                         int (*acceptable)(void *context, struct dentry *de),
                         void *context);
        int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len,
                         int connectable);

        /* the following are only called from the filesystem itself */
        int (*get_name)(struct dentry *parent, char *name,
                        struct dentry *child);
        struct dentry * (*get_parent)(struct dentry *child);
        struct dentry * (*get_dentry)(struct super_block *sb, void *inump);

        /* This is set by the exporting module to a standard helper */
        struct dentry * (*find_exported_dentry)(
                struct super_block *sb, void *obj, void *parent,
                int (*acceptable)(void *context, struct dentry *de),
                void *context);


};


struct file_system_type {
        const char *name;
        int fs_flags;
        struct super_block *(*get_sb) (struct file_system_type *, int, char *, void *);
        void (*kill_sb) (struct super_block *);
        struct module *owner;
        struct file_system_type * next;
        struct list_head fs_supers;
};

struct super_block *get_sb_bdev(struct file_system_type *fs_type,
        int flags, char *dev_name, void * data,
        int (*fill_super)(struct super_block *, void *, int));
struct super_block *get_sb_single(struct file_system_type *fs_type,
        int flags, void *data,
        int (*fill_super)(struct super_block *, void *, int));
struct super_block *get_sb_nodev(struct file_system_type *fs_type,
        int flags, void *data,
        int (*fill_super)(struct super_block *, void *, int));
void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
void kill_anon_super(struct super_block *sb);
void kill_litter_super(struct super_block *sb);
void deactivate_super(struct super_block *sb);
int set_anon_super(struct super_block *s, void *data);
struct super_block *sget(struct file_system_type *type,
                        int (*test)(struct super_block *,void *),
                        int (*set)(struct super_block *,void *),
                        void *data);
struct super_block *get_sb_pseudo(struct file_system_type *, char *,
                        struct super_operations *ops, unsigned long);

/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
#define fops_get(fops) \
        (((fops) && (fops)->owner)      \
                ? ( try_inc_mod_count((fops)->owner) ? (fops) : NULL ) \
                : (fops))

#define fops_put(fops) \
do {    \
        if ((fops) && (fops)->owner) \
                __MOD_DEC_USE_COUNT((fops)->owner);     \
} while(0)

extern int register_filesystem(struct file_system_type *);
extern int unregister_filesystem(struct file_system_type *);
extern struct vfsmount *kern_mount(struct file_system_type *);
extern int may_umount(struct vfsmount *);
extern long do_mount(char *, char *, char *, unsigned long, void *);

#define kern_umount mntput

extern int vfs_statfs(struct super_block *, struct statfs *);

/* Return value for VFS lock functions - tells locks.c to lock conventionally
 * REALLY kosha for root NFS and nfs_lock
 */ 
#define LOCK_USE_CLNT 1

#define FLOCK_VERIFY_READ  1
#define FLOCK_VERIFY_WRITE 2

extern int locks_mandatory_locked(struct inode *);
extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);

/*
 * Candidates for mandatory locking have the setgid bit set
 * but no group execute bit -  an otherwise meaningless combination.
 */
#define MANDATORY_LOCK(inode) \
        (IS_MANDLOCK(inode) && ((inode)->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)

static inline int locks_verify_locked(struct inode *inode)
{
        if (MANDATORY_LOCK(inode))
                return locks_mandatory_locked(inode);
        return 0;
}

static inline int locks_verify_area(int read_write, struct inode *inode,
                                    struct file *filp, loff_t offset,
                                    size_t count)
{
        if (inode->i_flock && MANDATORY_LOCK(inode))
                return locks_mandatory_area(read_write, inode, filp, offset, count);
        return 0;
}

static inline int locks_verify_truncate(struct inode *inode,
                                    struct file *filp,
                                    loff_t size)
{
        if (inode->i_flock && MANDATORY_LOCK(inode))
                return locks_mandatory_area(
                        FLOCK_VERIFY_WRITE, inode, filp,
                        size < inode->i_size ? size : inode->i_size,
                        (size < inode->i_size ? inode->i_size - size
                         : size - inode->i_size)
                );
        return 0;
}

static inline int get_lease(struct inode *inode, unsigned int mode)
{
        if (inode->i_flock && (inode->i_flock->fl_flags & FL_LEASE))
                return __get_lease(inode, mode);
        return 0;
}

/* fs/open.c */

asmlinkage long sys_open(const char *, int, int);
asmlinkage long sys_close(unsigned int);        /* yes, it's really unsigned */
extern int do_truncate(struct dentry *, loff_t start);

extern struct file *filp_open(const char *, int, int);
extern struct file * dentry_open(struct dentry *, struct vfsmount *, int);
extern int filp_close(struct file *, fl_owner_t id);
extern char * getname(const char *);

/* fs/dcache.c */
extern void vfs_caches_init(unsigned long);

#define __getname()     kmem_cache_alloc(names_cachep, SLAB_KERNEL)
#define putname(name)   kmem_cache_free(names_cachep, (void *)(name))

enum {BDEV_FILE, BDEV_SWAP, BDEV_FS, BDEV_RAW};
extern int register_blkdev(unsigned int, const char *, struct block_device_operations *);
extern int unregister_blkdev(unsigned int, const char *);
extern struct block_device *bdget(dev_t);
extern int bd_acquire(struct inode *inode);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
extern struct char_device *cdget(dev_t);
extern void cdput(struct char_device *);
extern int blkdev_open(struct inode *, struct file *);
extern int blkdev_close(struct inode *, struct file *);
extern struct file_operations def_blk_fops;
extern struct address_space_operations def_blk_aops;
extern struct file_operations def_fifo_fops;
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
extern int blkdev_ioctl(struct inode *, struct file *, unsigned, unsigned long);
extern int blkdev_get(struct block_device *, mode_t, unsigned, int);
extern int blkdev_put(struct block_device *, int);
extern int bd_claim(struct block_device *, void *);
extern void bd_release(struct block_device *);
extern void blk_run_queues(void);

/* fs/devices.c */
extern int register_chrdev(unsigned int, const char *, struct file_operations *);
extern int unregister_chrdev(unsigned int, const char *);
extern int chrdev_open(struct inode *, struct file *);
extern const char *__bdevname(dev_t);
extern inline const char *bdevname(struct block_device *bdev)
{
        return __bdevname(bdev->bd_dev);
}
extern const char * cdevname(kdev_t);
extern const char * kdevname(kdev_t);
extern void init_special_inode(struct inode *, umode_t, int);

/* Invalid inode operations -- fs/bad_inode.c */
extern void make_bad_inode(struct inode *);
extern int is_bad_inode(struct inode *);

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 int fs_may_remount_ro(struct super_block *);

/*
 * return READ, READA, or WRITE
 */
#define bio_rw(bio)             ((bio)->bi_rw & (RW_MASK | RWA_MASK))

/*
 * return data direction, READ or WRITE
 */
#define bio_data_dir(bio)       ((bio)->bi_rw & 1)

extern int check_disk_change(struct block_device *);
extern int full_check_disk_change(struct block_device *);
extern int __check_disk_change(dev_t);
extern int invalidate_inodes(struct super_block *);
extern int invalidate_device(kdev_t, int);
extern void invalidate_inode_pages(struct address_space *mapping);
extern void invalidate_inode_pages2(struct address_space *mapping);
extern void write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
extern int filemap_fdatawait(struct address_space *);
extern void sync_supers(void);
extern sector_t bmap(struct inode *, sector_t);
extern int setattr_mask(unsigned int);
extern int notify_change(struct dentry *, struct iattr *);
extern int permission(struct inode *, int);
extern int vfs_permission(struct inode *, int);
extern int get_write_access(struct inode *);
extern int deny_write_access(struct file *);
static inline void put_write_access(struct inode * inode)
{
        atomic_dec(&inode->i_writecount);
}
static inline void allow_write_access(struct file *file)
{
        if (file)
                atomic_inc(&file->f_dentry->d_inode->i_writecount);
}
extern int do_pipe(int *);

extern int open_namei(const char *, int, int, struct nameidata *);
extern int may_open(struct nameidata *, int, int);

extern int kernel_read(struct file *, unsigned long, char *, unsigned long);
extern struct file * open_exec(const char *);
 
/* fs/dcache.c -- generic fs support functions */
extern int is_subdir(struct dentry *, struct dentry *);
extern ino_t find_inode_number(struct dentry *, struct qstr *);

#include <linux/err.h>

/* needed for stackable file system support */
extern loff_t default_llseek(struct file *file, loff_t offset, int origin);

extern void inode_init_once(struct inode *);
extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
extern void generic_delete_inode(struct inode *inode);

extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
                int (*test)(struct inode *, void *), void *data);
extern struct inode *ilookup(struct super_block *sb, unsigned long ino);

extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
extern struct inode * iget_locked(struct super_block *, unsigned long);
extern void unlock_new_inode(struct inode *);

static inline struct inode *iget(struct super_block *sb, unsigned long ino)
{
        struct inode *inode = iget_locked(sb, ino);
        
        if (inode && (inode->i_state & I_NEW)) {
                sb->s_op->read_inode(inode);
                unlock_new_inode(inode);
        }

        return inode;
}

extern void __iget(struct inode * inode);
extern void clear_inode(struct inode *);
extern void destroy_inode(struct inode *);
extern struct inode *new_inode(struct super_block *);
extern void remove_suid(struct dentry *);

extern void __insert_inode_hash(struct inode *, unsigned long hashval);
extern void remove_inode_hash(struct inode *);
static inline void insert_inode_hash(struct inode *inode) {
        __insert_inode_hash(inode, inode->i_ino);
}

extern struct file * get_empty_filp(void);
extern void file_move(struct file *f, struct list_head *list);
struct bio;
extern int submit_bio(int, struct bio *);
extern int bdev_read_only(struct block_device *);
extern int set_blocksize(struct block_device *, int);
extern int sb_set_blocksize(struct super_block *, int);
extern int sb_min_blocksize(struct super_block *, int);

extern int generic_file_mmap(struct file *, struct vm_area_struct *);
extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
extern int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
extern ssize_t generic_file_read(struct file *, char *, size_t, loff_t *);
extern ssize_t generic_file_write(struct file *, const char *, size_t, loff_t *);
extern ssize_t generic_file_aio_read(struct kiocb *, char *, size_t, loff_t);
extern ssize_t generic_file_aio_write(struct kiocb *, const char *, size_t, loff_t);
extern ssize_t do_sync_read(struct file *filp, char *buf, size_t len, loff_t *ppos);
extern ssize_t do_sync_write(struct file *filp, const char *buf, size_t len, loff_t *ppos);
ssize_t generic_file_write_nolock(struct file *file, const struct iovec *iov,
                                unsigned long nr_segs, loff_t *ppos);
extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *);
extern void do_generic_mapping_read(struct address_space *, struct file_ra_state *, struct file *,
                                    loff_t *, read_descriptor_t *, read_actor_t);
extern void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
extern ssize_t generic_file_direct_IO(int rw, struct file *file,
        const struct iovec *iov, loff_t offset, unsigned long nr_segs);
extern int generic_direct_IO(int rw, struct inode *inode, struct block_device *bdev,
        const struct iovec *iov, loff_t offset, unsigned long nr_segs, get_blocks_t *get_blocks);
extern ssize_t generic_file_readv(struct file *filp, const struct iovec *iov, 
        unsigned long nr_segs, loff_t *ppos);
ssize_t generic_file_writev(struct file *filp, const struct iovec *iov, 
                        unsigned long nr_segs, loff_t *ppos);
extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
extern loff_t remote_llseek(struct file *file, loff_t offset, int origin);
extern int generic_file_open(struct inode * inode, struct file * filp);

extern int generic_vm_writeback(struct page *page,
                                struct writeback_control *wbc);

static inline void do_generic_file_read(struct file * filp, loff_t *ppos,
                                        read_descriptor_t * desc,
                                        read_actor_t actor)
{
        do_generic_mapping_read(filp->f_dentry->d_inode->i_mapping,
                                &filp->f_ra,
                                filp,
                                ppos,
                                desc,
                                actor);
}

extern struct file_operations generic_ro_fops;

extern int vfs_readlink(struct dentry *, char *, int, const char *);
extern int vfs_follow_link(struct nameidata *, const char *);
extern int page_readlink(struct dentry *, char *, int);
extern int page_follow_link(struct dentry *, struct nameidata *);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern struct inode_operations page_symlink_inode_operations;
extern void generic_fillattr(struct inode *, struct kstat *);
extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);

extern int vfs_readdir(struct file *, filldir_t, void *);

extern int vfs_stat(char *, struct kstat *);
extern int vfs_lstat(char *, struct kstat *);
extern int vfs_fstat(unsigned int, struct kstat *);

extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
extern struct super_block *user_get_super(dev_t);
extern void drop_super(struct super_block *sb);

extern int dcache_dir_open(struct inode *, struct file *);
extern int dcache_dir_close(struct inode *, struct file *);
extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
extern int dcache_readdir(struct file *, void *, filldir_t);
extern int simple_statfs(struct super_block *, struct statfs *);
extern int simple_link(struct dentry *, struct inode *, struct dentry *);
extern int simple_unlink(struct inode *, struct dentry *);
extern int simple_rmdir(struct inode *, struct dentry *);
extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
extern int simple_sync_file(struct file *, struct dentry *, int);
extern int simple_empty(struct dentry *);
extern int simple_readpage(struct file *file, struct page *page);
extern int simple_prepare_write(struct file *file, struct page *page,
                        unsigned offset, unsigned to);
extern int simple_commit_write(struct file *file, struct page *page,
                                unsigned offset, unsigned to);

extern struct dentry *simple_lookup(struct inode *, struct dentry *);
extern ssize_t generic_read_dir(struct file *, char *, size_t, loff_t *);
extern struct file_operations simple_dir_operations;
extern struct inode_operations simple_dir_inode_operations;

#ifdef CONFIG_BLK_DEV_INITRD
extern unsigned int real_root_dev;
#endif

extern int inode_change_ok(struct inode *, struct iattr *);
extern int inode_setattr(struct inode *, struct iattr *);

extern void inode_update_time(struct inode *inode, int ctime_too);

static inline ino_t parent_ino(struct dentry *dentry)
{
        ino_t res;
        read_lock(&dparent_lock);
        res = dentry->d_parent->d_inode->i_ino;
        read_unlock(&dparent_lock);
        return res;
}

#endif /* __KERNEL__ */
#endif /* _LINUX_FS_H */