#ifndef _LINUX_FS_H
  #define _LINUX_FS_H
  
  /*
   * This file has definitions for some important file table
   * structures etc.
   */

  #include <linux/limits.h>
  #include <linux/ioctl.h>
  
  /*
   * 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)

  #define SEEK_SET	0	/* seek relative to beginning of file */
  #define SEEK_CUR	1	/* seek relative to current file position */
  #define SEEK_END	2	/* seek relative to end of file */

  #define SEEK_MAX	SEEK_END

  /* 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;

  extern int get_max_files(void);

  
  struct inodes_stat_t {
  	int nr_inodes;
  	int nr_unused;
  	int dummy[5];
  };
  extern struct inodes_stat_t inodes_stat;
  
  extern int leases_enable, lease_break_time;
  
  #ifdef CONFIG_DNOTIFY
  extern int dir_notify_enable;
  #endif
  
  #define NR_FILE  8192	/* this can well be larger on a larger system */
  
  #define MAY_EXEC 1
  #define MAY_WRITE 2
  #define MAY_READ 4
  #define MAY_APPEND 8
  
  #define FMODE_READ 1
  #define FMODE_WRITE 2
  
  /* Internal kernel extensions */
  #define FMODE_LSEEK	4
  #define FMODE_PREAD	8
  #define FMODE_PWRITE	FMODE_PREAD	/* These go hand in hand */

  /* File is being opened for execution. Primary users of this flag are
     distributed filesystems that can use it to achieve correct ETXTBUSY
     behavior for cross-node execution/opening_for_writing of files */
  #define FMODE_EXEC	16

  #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 SWRITE 3	/* for ll_rw_block() - wait for buffer lock */

  #define READ_SYNC	(READ | (1 << BIO_RW_SYNC))

  #define READ_META	(READ | (1 << BIO_RW_META))

  #define WRITE_SYNC	(WRITE | (1 << BIO_RW_SYNC))
  #define WRITE_BARRIER	((1 << BIO_RW) | (1 << BIO_RW_BARRIER))
  
  #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_BINARY_MOUNTDATA 2

  #define FS_HAS_SUBTYPE 4

  #define FS_REVAL_DOT	16384	/* Check the paths ".", ".." for staleness */

  #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move()
  					 * during rename() internally.
  					 */

  /*
   * 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	/* War is peace. Verbosity is silence.
  				   MS_VERBOSE is deprecated. */
  #define MS_SILENT	32768

  #define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */

  #define MS_UNBINDABLE	(1<<17)	/* change to unbindable */

  #define MS_PRIVATE	(1<<18)	/* change to private */

  #define MS_SLAVE	(1<<19)	/* change to slave */

  #define MS_SHARED	(1<<20)	/* change to shared */

  #define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */

  #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)

  
  /*
   * 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_APPEND	4	/* Append-only file */
  #define S_IMMUTABLE	8	/* Immutable file */
  #define S_DEAD		16	/* removed, but still open directory */
  #define S_NOQUOTA	32	/* Inode is not counted to quota */
  #define S_DIRSYNC	64	/* Directory modifications are synchronous */
  #define S_NOCMTIME	128	/* Do not update file c/mtime */
  #define S_SWAPFILE	256	/* Do not truncate: swapon got its bmaps */
  #define S_PRIVATE	512	/* Inode is fs-internal */
  
  /*
   * 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_NOATIME(inode)   __IS_FLG(inode, MS_RDONLY|MS_NOATIME)

  
  #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_POSIXACL(inode)	__IS_FLG(inode, MS_POSIXACL)
  
  #define IS_DEADDIR(inode)	((inode)->i_flags & S_DEAD)
  #define IS_NOCMTIME(inode)	((inode)->i_flags & S_NOCMTIME)
  #define IS_SWAPFILE(inode)	((inode)->i_flags & S_SWAPFILE)
  #define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
  
  /* 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 */
  
  /* Some people are morons.  Do not use sizeof! */
  
  #define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
  #define BLKELVSET  _IOW(0x12,107,size_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,size_t)
  #define BLKBSZSET  _IOW(0x12,113,size_t)
  #define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */

  #define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
  #define BLKTRACESTART _IO(0x12,116)
  #define BLKTRACESTOP _IO(0x12,117)
  #define BLKTRACETEARDOWN _IO(0x12,118)

  
  #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 */

  #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
  #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
  #define	FS_IOC_GETVERSION		_IOR('v', 1, long)
  #define	FS_IOC_SETVERSION		_IOW('v', 2, long)
  #define FS_IOC32_GETFLAGS		_IOR('f', 1, int)
  #define FS_IOC32_SETFLAGS		_IOW('f', 2, int)
  #define FS_IOC32_GETVERSION		_IOR('v', 1, int)
  #define FS_IOC32_SETVERSION		_IOW('v', 2, int)
  
  /*
   * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
   */
  #define	FS_SECRM_FL			0x00000001 /* Secure deletion */
  #define	FS_UNRM_FL			0x00000002 /* Undelete */
  #define	FS_COMPR_FL			0x00000004 /* Compress file */
  #define FS_SYNC_FL			0x00000008 /* Synchronous updates */
  #define FS_IMMUTABLE_FL			0x00000010 /* Immutable file */
  #define FS_APPEND_FL			0x00000020 /* writes to file may only append */
  #define FS_NODUMP_FL			0x00000040 /* do not dump file */
  #define FS_NOATIME_FL			0x00000080 /* do not update atime */
  /* Reserved for compression usage... */
  #define FS_DIRTY_FL			0x00000100
  #define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
  #define FS_NOCOMP_FL			0x00000400 /* Don't compress */
  #define FS_ECOMPR_FL			0x00000800 /* Compression error */
  /* End compression flags --- maybe not all used */
  #define FS_BTREE_FL			0x00001000 /* btree format dir */
  #define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
  #define FS_IMAGIC_FL			0x00002000 /* AFS directory */
  #define FS_JOURNAL_DATA_FL		0x00004000 /* Reserved for ext3 */
  #define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
  #define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
  #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/

  #define FS_EXTENT_FL			0x00080000 /* Extents */
  #define FS_DIRECTIO_FL			0x00100000 /* Use direct i/o */

  #define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */
  
  #define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
  #define FS_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */

  #define SYNC_FILE_RANGE_WAIT_BEFORE	1
  #define SYNC_FILE_RANGE_WRITE		2
  #define SYNC_FILE_RANGE_WAIT_AFTER	4

  #ifdef __KERNEL__
  
  #include <linux/linkage.h>
  #include <linux/wait.h>
  #include <linux/types.h>
  #include <linux/kdev_t.h>
  #include <linux/dcache.h>

  #include <linux/namei.h>

  #include <linux/stat.h>
  #include <linux/cache.h>
  #include <linux/kobject.h>
  #include <linux/list.h>
  #include <linux/radix-tree.h>
  #include <linux/prio_tree.h>
  #include <linux/init.h>

  #include <linux/pid.h>

  #include <linux/mutex.h>

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

  struct hd_geometry;

  struct iovec;
  struct nameidata;

  struct kiocb;

  struct pipe_inode_info;
  struct poll_table_struct;
  struct kstatfs;
  struct vm_area_struct;
  struct vfsmount;

  extern void __init inode_init(unsigned long);
  extern void __init inode_init_early(void);
  extern void __init mnt_init(unsigned long);
  extern void __init 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 void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,

  			ssize_t bytes, void *private);
  
  /*
   * 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

  #define ATTR_FILE	8192

  
  /*
   * 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;

  
  	/*
  	 * Not an attribute, but an auxilary info for filesystems wanting to
  	 * implement an ftruncate() like method.  NOTE: filesystem should
  	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
  	 */
  	struct file	*ia_file;

  };
  
  /*

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

  /** 
   * enum positive_aop_returns - aop return codes with specific semantics
   *
   * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
   * 			    completed, that the page is still locked, and
   * 			    should be considered active.  The VM uses this hint
   * 			    to return the page to the active list -- it won't
   * 			    be a candidate for writeback again in the near
   * 			    future.  Other callers must be careful to unlock
   * 			    the page if they get this return.  Returned by
   * 			    writepage(); 
   *
   * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
   *  			unlocked it and the page might have been truncated.
   *  			The caller should back up to acquiring a new page and
   *  			trying again.  The aop will be taking reasonable
   *  			precautions not to livelock.  If the caller held a page
   *  			reference, it should drop it before retrying.  Returned
   *  			by readpage(), prepare_write(), and commit_write().
   *
   * address_space_operation functions return these large constants to indicate
   * special semantics to the caller.  These are much larger than the bytes in a
   * page to allow for functions that return the number of bytes operated on in a
   * given page.
   */
  
  enum positive_aop_returns {
  	AOP_WRITEPAGE_ACTIVATE	= 0x80000,
  	AOP_TRUNCATED_PAGE	= 0x80001,
  };

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

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

  	void (*sync_page)(struct page *);

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

  	/* Set a page dirty.  Return true if this dirtied it */

  	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);

  	void (*invalidatepage) (struct page *, unsigned long);

  	int (*releasepage) (struct page *, gfp_t);

  	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
  			loff_t offset, unsigned long nr_segs);

  	struct page* (*get_xip_page)(struct address_space *, sector_t,
  			int);

  	/* migrate the contents of a page to the specified target */

  	int (*migratepage) (struct address_space *,
  			struct page *, struct page *);

  	int (*launder_page) (struct page *);

  };
  
  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		tree_lock;	/* and rwlock protecting it */
  	unsigned int		i_mmap_writable;/* count VM_SHARED mappings */
  	struct prio_tree_root	i_mmap;		/* tree of private and shared mappings */
  	struct list_head	i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
  	spinlock_t		i_mmap_lock;	/* protect tree, count, list */
  	unsigned int		truncate_count;	/* Cover race condition with truncate */
  	unsigned long		nrpages;	/* number of total pages */
  	pgoff_t			writeback_index;/* writeback starts here */

  	const struct address_space_operations *a_ops;	/* methods */

  	unsigned long		flags;		/* error bits/gfp mask */
  	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 */
  } __attribute__((aligned(sizeof(long))));
  	/*
  	 * On most architectures that alignment is already the case; but
  	 * must be enforced here for CRIS, to let the least signficant bit
  	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
  	 */
  
  struct block_device {
  	dev_t			bd_dev;  /* not a kdev_t - it's a search key */
  	struct inode *		bd_inode;	/* will die */
  	int			bd_openers;

  	struct mutex		bd_mutex;	/* open/close mutex */

  	struct semaphore	bd_mount_sem;

  	struct list_head	bd_inodes;
  	void *			bd_holder;
  	int			bd_holders;

  #ifdef CONFIG_SYSFS
  	struct list_head	bd_holder_list;
  #endif

  	struct block_device *	bd_contains;
  	unsigned		bd_block_size;
  	struct hd_struct *	bd_part;
  	/* number of times partitions within this device have been opened. */
  	unsigned		bd_part_count;
  	int			bd_invalidated;
  	struct gendisk *	bd_disk;
  	struct list_head	bd_list;
  	struct backing_dev_info *bd_inode_backing_dev_info;
  	/*
  	 * Private data.  You must have bd_claim'ed the block_device
  	 * to use this.  NOTE:  bd_claim allows an owner to claim
  	 * the same device multiple times, the owner must take special
  	 * care to not mess up bd_private for that case.
  	 */
  	unsigned long		bd_private;
  };
  
  /*
   * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
   * radix trees
   */
  #define PAGECACHE_TAG_DIRTY	0
  #define PAGECACHE_TAG_WRITEBACK	1
  
  int mapping_tagged(struct address_space *mapping, int tag);
  
  /*
   * Might pages of this file be mapped into userspace?
   */
  static inline int mapping_mapped(struct address_space *mapping)
  {
  	return	!prio_tree_empty(&mapping->i_mmap) ||
  		!list_empty(&mapping->i_mmap_nonlinear);
  }
  
  /*
   * Might pages of this file have been modified in userspace?
   * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
   * marks vma as VM_SHARED if it is shared, and the file was opened for
   * writing i.e. vma may be mprotected writable even if now readonly.
   */
  static inline int mapping_writably_mapped(struct address_space *mapping)
  {
  	return mapping->i_mmap_writable != 0;
  }
  
  /*
   * Use sequence counter to get consistent i_size on 32-bit processors.
   */
  #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
  #include <linux/seqlock.h>
  #define __NEED_I_SIZE_ORDERED
  #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
  #else
  #define i_size_ordered_init(inode) do { } while (0)
  #endif
  
  struct inode {
  	struct hlist_node	i_hash;
  	struct list_head	i_list;
  	struct list_head	i_sb_list;
  	struct list_head	i_dentry;
  	unsigned long		i_ino;
  	atomic_t		i_count;

  	unsigned int		i_nlink;
  	uid_t			i_uid;
  	gid_t			i_gid;
  	dev_t			i_rdev;

  	unsigned long		i_version;

  	loff_t			i_size;

  #ifdef __NEED_I_SIZE_ORDERED
  	seqcount_t		i_size_seqcount;
  #endif

  	struct timespec		i_atime;
  	struct timespec		i_mtime;
  	struct timespec		i_ctime;
  	unsigned int		i_blkbits;

  	blkcnt_t		i_blocks;

  	unsigned short          i_bytes;

  	umode_t			i_mode;

  	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */

  	struct mutex		i_mutex;

  	struct rw_semaphore	i_alloc_sem;

  	const struct inode_operations	*i_op;

  	const 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;
  #ifdef CONFIG_QUOTA
  	struct dquot		*i_dquot[MAXQUOTAS];
  #endif

  	struct list_head	i_devices;

  	union {
  		struct pipe_inode_info	*i_pipe;

  		struct block_device	*i_bdev;

  		struct cdev		*i_cdev;

  	};

  	int			i_cindex;
  
  	__u32			i_generation;
  
  #ifdef CONFIG_DNOTIFY
  	unsigned long		i_dnotify_mask; /* Directory notify events */
  	struct dnotify_struct	*i_dnotify; /* for directory notifications */
  #endif

  #ifdef CONFIG_INOTIFY
  	struct list_head	inotify_watches; /* watches on this inode */

  	struct mutex		inotify_mutex;	/* protects the watches list */

  #endif

  	unsigned long		i_state;
  	unsigned long		dirtied_when;	/* jiffies of first dirtying */
  
  	unsigned int		i_flags;
  
  	atomic_t		i_writecount;

  #ifdef CONFIG_SECURITY

  	void			*i_security;

  #endif

  	void			*i_private; /* fs or device private pointer */

  };
  
  /*

   * inode->i_mutex nesting subclasses for the lock validator:
   *
   * 0: the object of the current VFS operation
   * 1: parent
   * 2: child/target
   * 3: quota file
   *
   * The locking order between these classes is

   * parent -> child -> normal -> xattr -> quota

   */
  enum inode_i_mutex_lock_class
  {
  	I_MUTEX_NORMAL,
  	I_MUTEX_PARENT,
  	I_MUTEX_CHILD,

  	I_MUTEX_XATTR,

  	I_MUTEX_QUOTA
  };

  extern void inode_double_lock(struct inode *inode1, struct inode *inode2);
  extern void inode_double_unlock(struct inode *inode1, struct inode *inode2);

  /*

   * NOTE: in a 32bit arch with a preemptable kernel and
   * an UP compile the i_size_read/write must be atomic
   * with respect to the local cpu (unlike with preempt disabled),
   * but they don't need to be atomic with respect to other cpus like in
   * true SMP (so they need either to either locally disable irq around
   * the read or for example on x86 they can be still implemented as a
   * cmpxchg8b without the need of the lock prefix). For SMP compiles
   * and 64bit archs it makes no difference if preempt is enabled or not.
   */

  static inline loff_t i_size_read(const struct inode *inode)

  {
  #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
  	loff_t i_size;
  	unsigned int seq;
  
  	do {
  		seq = read_seqcount_begin(&inode->i_size_seqcount);
  		i_size = inode->i_size;
  	} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
  	return i_size;
  #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
  	loff_t i_size;
  
  	preempt_disable();
  	i_size = inode->i_size;
  	preempt_enable();
  	return i_size;
  #else
  	return inode->i_size;
  #endif
  }

  /*
   * NOTE: unlike i_size_read(), i_size_write() does need locking around it
   * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
   * can be lost, resulting in subsequent i_size_read() calls spinning forever.
   */

  static inline void i_size_write(struct inode *inode, loff_t i_size)
  {
  #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
  	write_seqcount_begin(&inode->i_size_seqcount);
  	inode->i_size = i_size;
  	write_seqcount_end(&inode->i_size_seqcount);
  #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
  	preempt_disable();
  	inode->i_size = i_size;
  	preempt_enable();
  #else
  	inode->i_size = i_size;
  #endif
  }

  static inline unsigned iminor(const struct inode *inode)

  {
  	return MINOR(inode->i_rdev);
  }

  static inline unsigned imajor(const struct inode *inode)

  {
  	return MAJOR(inode->i_rdev);
  }
  
  extern struct block_device *I_BDEV(struct inode *inode);
  
  struct fown_struct {
  	rwlock_t lock;          /* protects pid, uid, euid fields */

  	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
  	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */

  	uid_t uid, euid;	/* uid/euid of process setting the owner */

  	int signum;		/* posix.1b rt signal to be delivered on IO */
  };
  
  /*
   * Track a single file's readahead state
   */
  struct file_ra_state {
  	unsigned long start;		/* Current window */
  	unsigned long size;
  	unsigned long flags;		/* ra flags RA_FLAG_xxx*/
  	unsigned long cache_hit;	/* cache hit count*/

  	unsigned long prev_index;	/* Cache last read() position */

  	unsigned long ahead_start;	/* Ahead window */
  	unsigned long ahead_size;
  	unsigned long ra_pages;		/* Maximum readahead window */
  	unsigned long mmap_hit;		/* Cache hit stat for mmap accesses */
  	unsigned long mmap_miss;	/* Cache miss stat for mmap accesses */

  	unsigned int prev_offset;	/* Offset where last read() ended in a page */

  };
  #define RA_FLAG_MISS 0x01	/* a cache miss occured against this file */
  #define RA_FLAG_INCACHE 0x02	/* file is already in cache */
  
  struct file {

  	/*
  	 * fu_list becomes invalid after file_free is called and queued via
  	 * fu_rcuhead for RCU freeing
  	 */
  	union {
  		struct list_head	fu_list;
  		struct rcu_head 	fu_rcuhead;
  	} f_u;

  	struct path		f_path;
  #define f_dentry	f_path.dentry
  #define f_vfsmnt	f_path.mnt

  	const 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;
  	struct file_ra_state	f_ra;

  	unsigned long		f_version;

  #ifdef CONFIG_SECURITY

  	void			*f_security;

  #endif

  	/* needed for tty driver, and maybe others */
  	void			*private_data;
  
  #ifdef CONFIG_EPOLL
  	/* Used by fs/eventpoll.c to link all the hooks to this file */
  	struct list_head	f_ep_links;
  	spinlock_t		f_ep_lock;
  #endif /* #ifdef CONFIG_EPOLL */
  	struct address_space	*f_mapping;
  };
  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)
  
  #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 	0x7fffffffffffffffUL
  #endif
  
  #define FL_POSIX	1
  #define FL_FLOCK	2
  #define FL_ACCESS	8	/* not trying to lock, just looking */

  #define FL_EXISTS	16	/* when unlocking, test for existence */

  #define FL_LEASE	32	/* lease held on this file */

  #define FL_CLOSE	64	/* unlock on close */

  #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;
  
  struct file_lock_operations {
  	void (*fl_insert)(struct file_lock *);	/* lock insertion callback */
  	void (*fl_remove)(struct file_lock *);	/* lock removal callback */
  	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
  	void (*fl_release_private)(struct file_lock *);
  };
  
  struct lock_manager_operations {
  	int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
  	void (*fl_notify)(struct file_lock *);	/* unblock callback */

  	int (*fl_grant)(struct file_lock *, struct file_lock *, int);

  	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
  	void (*fl_release_private)(struct file_lock *);
  	void (*fl_break)(struct file_lock *);
  	int (*fl_mylease)(struct file_lock *, struct file_lock *);
  	int (*fl_change)(struct file_lock **, int);
  };
  
  /* 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;
  
  	struct fasync_struct *	fl_fasync; /* for lease break notifications */
  	unsigned long fl_break_time;	/* for nonblocking lease breaks */
  
  	struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
  	struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
  	union {
  		struct nfs_lock_info	nfs_fl;

  		struct nfs4_lock_info	nfs4_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

  #include <linux/fcntl.h>
  
  extern int fcntl_getlk(struct file *, struct flock __user *);

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

  
  #if BITS_PER_LONG == 32
  extern int fcntl_getlk64(struct file *, struct flock64 __user *);

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

  #endif
  
  extern void send_sigio(struct fown_struct *fown, int fd, int band);
  extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
  extern int fcntl_getlease(struct file *filp);

  /* fs/sync.c */

  extern int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
  			loff_t endbyte, unsigned int flags);

  /* 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 int posix_test_lock(struct file *, struct file_lock *);

  extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);

  extern int posix_lock_file_wait(struct file *, struct file_lock *);

  extern int posix_unblock_lock(struct file *, struct file_lock *);

  extern int vfs_test_lock(struct file *, struct file_lock *);

  extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);

  extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);

  extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
  extern int __break_lease(struct inode *inode, unsigned int flags);
  extern void lease_get_mtime(struct inode *, struct timespec *time);
  extern int setlease(struct file *, long, struct file_lock **);
  extern int lease_modify(struct file_lock **, int);
  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, struct pid *, enum pid_type, int force);

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

  extern pid_t f_getown(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 */
  #define MNT_EXPIRE	0x00000004	/* Mark for expiry */
  
  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 char		s_blocksize_bits;
  	unsigned char		s_dirt;
  	unsigned long long	s_maxbytes;	/* Max file size */
  	struct file_system_type	*s_type;

  	const 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 mutex		s_lock;

  	int			s_count;
  	int			s_syncing;
  	int			s_need_sync_fs;
  	atomic_t		s_active;

  #ifdef CONFIG_SECURITY

  	void                    *s_security;

  #endif

  	struct xattr_handler	**s_xattr;
  
  	struct list_head	s_inodes;	/* all inodes */
  	struct list_head	s_dirty;	/* dirty inodes */
  	struct list_head	s_io;		/* parked for writeback */
  	struct hlist_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 */
  
  	int			s_frozen;
  	wait_queue_head_t	s_wait_unfrozen;
  
  	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 mutex s_vfs_rename_mutex;	/* Kludge */

  	/* Granularity of c/m/atime in ns.

  	   Cannot be worse than a second */
  	u32		   s_time_gran;

  
  	/*
  	 * Filesystem subtype.  If non-empty the filesystem type field
  	 * in /proc/mounts will be "type.subtype"
  	 */
  	char *s_subtype;

  };
  
  extern struct timespec current_fs_time(struct super_block *sb);
  
  /*
   * Snapshotting support.
   */
  enum {
  	SB_UNFROZEN = 0,
  	SB_FREEZE_WRITE	= 1,
  	SB_FREEZE_TRANS = 2,
  };
  
  #define vfs_check_frozen(sb, level) \
  	wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level)))

  #define get_fs_excl() atomic_inc(&current->fs_excl)
  #define put_fs_excl() atomic_dec(&current->fs_excl)
  #define has_fs_excl() atomic_read(&current->fs_excl)

  /* not quite ready to be deprecated, but... */
  extern void lock_super(struct super_block *);
  extern void unlock_super(struct super_block *);

  
  /*
   * VFS helper functions..
   */

  extern int vfs_permission(struct nameidata *, int);

  extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *);
  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 *, int);
  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 *);
  
  /*
   * VFS dentry helper functions.
   */
  extern void dentry_unhash(struct dentry *dentry);
  
  /*

   * VFS file helper functions.
   */
  extern int file_permission(struct file *, int);
  
  /*

   * 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
  
  #define OSYNC_METADATA	(1<<0)
  #define OSYNC_DATA	(1<<1)
  #define OSYNC_INODE	(1<<2)
  int generic_osync_inode(struct inode *, struct address_space *, int);
  
  /*
   * 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, u64, 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);

  	long (*unlocked_ioctl) (struct file *, unsigned, unsigned long);

  	long (*compat_ioctl) (struct file *, unsigned, unsigned long);

  	int (*direct_access) (struct block_device *, sector_t, unsigned long *);

  	int (*media_changed) (struct gendisk *);
  	int (*revalidate_disk) (struct gendisk *);

  	int (*getgeo)(struct block_device *, struct hd_geometry *);

  	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;
  	union {
  		char __user * buf;
  		void *data;
  	} arg;
  	int error;
  } read_descriptor_t;
  
  typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long);
  
  /* These macros are for out of kernel modules to test that
   * the kernel supports the unlocked_ioctl and compat_ioctl
   * fields in struct file_operations. */
  #define HAVE_COMPAT_IOCTL 1
  #define HAVE_UNLOCKED_IOCTL 1
  
  /*
   * NOTE:
   * read, write, poll, fsync, readv, writev, unlocked_ioctl and compat_ioctl
   * can be called without the big kernel lock held in all filesystems.
   */
  struct file_operations {
  	struct module *owner;
  	loff_t (*llseek) (struct file *, loff_t, int);
  	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);

  	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);

  	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
  	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, 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);
  	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
  	int (*mmap) (struct file *, struct vm_area_struct *);
  	int (*open) (struct inode *, struct file *);

  	int (*flush) (struct file *, fl_owner_t id);

  	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 (*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);
  	int (*check_flags)(int);
  	int (*dir_notify)(struct file *filp, unsigned long arg);
  	int (*flock) (struct file *, int, struct file_lock *);

  	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
  	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);

  };
  
  struct inode_operations {
  	int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
  	struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
  	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,dev_t);
  	int (*rename) (struct inode *, struct dentry *,
  			struct inode *, struct dentry *);
  	int (*readlink) (struct dentry *, char __user *,int);

  	void * (*follow_link) (struct dentry *, struct nameidata *);
  	void (*put_link) (struct dentry *, struct nameidata *, void *);

  	void (*truncate) (struct inode *);
  	int (*permission) (struct inode *, int, struct nameidata *);
  	int (*setattr) (struct dentry *, struct iattr *);
  	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
  	int (*setxattr) (struct dentry *, const char *,const 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 *);

  	void (*truncate_range)(struct inode *, loff_t, loff_t);

  };
  
  struct seq_file;

  ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
  				unsigned long nr_segs, unsigned long fast_segs,
  				struct iovec *fast_pointer,
  				struct iovec **ret_pointer);

  extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
  extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
  extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
  		unsigned long, loff_t *);
  extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
  		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 *);
  	int (*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 *);
  	int (*sync_fs)(struct super_block *sb, int wait);
  	void (*write_super_lockfs) (struct super_block *);
  	void (*unlockfs) (struct super_block *);

  	int (*statfs) (struct dentry *, struct kstatfs *);

  	int (*remount_fs) (struct super_block *, int *, char *);
  	void (*clear_inode) (struct inode *);

  	void (*umount_begin) (struct vfsmount *, int);

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

  	int (*show_stats)(struct seq_file *, struct vfsmount *);

  #ifdef CONFIG_QUOTA

  	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
  	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);

  #endif

  };
  
  /* 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		3
  #define I_LOCK			(1 << __I_LOCK)
  #define I_FREEING		16
  #define I_CLEAR			32
  #define I_NEW			64

  #define I_WILL_FREE		128

  
  #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);
  }

  static inline void inc_nlink(struct inode *inode)

  {
  	inode->i_nlink++;

  }
  
  static inline void inode_inc_link_count(struct inode *inode)
  {
  	inc_nlink(inode);

  	mark_inode_dirty(inode);
  }

  static inline void drop_nlink(struct inode *inode)

  {
  	inode->i_nlink--;

  }

  static inline void clear_nlink(struct inode *inode)
  {
  	inode->i_nlink = 0;
  }

  static inline void inode_dec_link_count(struct inode *inode)
  {
  	drop_nlink(inode);

  	mark_inode_dirty(inode);
  }

  extern void touch_atime(struct vfsmount *mnt, struct dentry *dentry);

  static inline void file_accessed(struct file *file)
  {
  	if (!(file->f_flags & O_NOATIME))

  		touch_atime(file->f_path.mnt, file->f_path.dentry);

  }
  
  int sync_inode(struct inode *inode, struct writeback_control *wbc);
  
  /**

   * struct 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

   * @find_exported_dentry:
   *	set by the exporting module to a standard helper function.

   *
   * 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_mutex 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_mutex 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);
  
  
  };
  
  extern 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;

  	int (*get_sb) (struct file_system_type *, int,
  		       const char *, void *, struct vfsmount *);

  	void (*kill_sb) (struct super_block *);
  	struct module *owner;
  	struct file_system_type * next;
  	struct list_head fs_supers;

  	struct lock_class_key s_lock_key;

  	struct lock_class_key s_umount_key;

  };

  extern int get_sb_bdev(struct file_system_type *fs_type,

  	int flags, const char *dev_name, void *data,

  	int (*fill_super)(struct super_block *, void *, int),
  	struct vfsmount *mnt);
  extern int get_sb_single(struct file_system_type *fs_type,

  	int flags, void *data,

  	int (*fill_super)(struct super_block *, void *, int),
  	struct vfsmount *mnt);
  extern int get_sb_nodev(struct file_system_type *fs_type,

  	int flags, void *data,

  	int (*fill_super)(struct super_block *, void *, int),
  	struct vfsmount *mnt);

  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);

  extern int get_sb_pseudo(struct file_system_type *, char *,

  	const struct super_operations *ops, unsigned long,

  	struct vfsmount *mnt);
  extern int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb);

  int __put_super(struct super_block *sb);
  int __put_super_and_need_restart(struct super_block *sb);
  void unnamed_dev_init(void);
  
  /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
  #define fops_get(fops) \
  	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
  #define fops_put(fops) \
  	do { if (fops) module_put((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_tree(struct vfsmount *);
  extern int may_umount(struct vfsmount *);

  extern void umount_tree(struct vfsmount *, int, struct list_head *);

  extern void release_mounts(struct list_head *);

  extern long do_mount(char *, char *, char *, unsigned long, void *);

  extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int);
  extern void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
  				  struct vfsmount *);

  extern int vfs_statfs(struct dentry *, struct kstatfs *);

  /* /sys/fs */

  extern struct kset fs_subsys;

  #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;
  }
  
  extern int rw_verify_area(int, struct file *, loff_t *, size_t);
  
  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 break_lease(struct inode *inode, unsigned int mode)
  {
  	if (inode->i_flock)
  		return __break_lease(inode, mode);
  	return 0;
  }
  
  /* fs/open.c */

  extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
  		       struct file *filp);

  extern long do_sys_open(int fdf, const char __user *filename, int flags,
  			int mode);

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

  extern struct kmem_cache *names_cachep;

  #define __getname()	kmem_cache_alloc(names_cachep, GFP_KERNEL)

  #define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
  #ifndef CONFIG_AUDITSYSCALL
  #define putname(name)   __putname(name)
  #else
  extern void putname(const char *name);
  #endif

  #ifdef CONFIG_BLOCK

  extern int register_blkdev(unsigned int, const char *);
  extern int unregister_blkdev(unsigned int, const char *);
  extern struct block_device *bdget(dev_t);
  extern void bd_set_size(struct block_device *, loff_t size);
  extern void bd_forget(struct inode *inode);
  extern void bdput(struct block_device *);
  extern struct block_device *open_by_devnum(dev_t, unsigned);

  extern const struct address_space_operations def_blk_aops;

  #else
  static inline void bd_forget(struct inode *inode) {}
  #endif
  extern const struct file_operations def_blk_fops;

  extern const struct file_operations def_chr_fops;
  extern const struct file_operations bad_sock_fops;
  extern const struct file_operations def_fifo_fops;

  #ifdef CONFIG_BLOCK

  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_driver_ioctl(struct inode *inode, struct file *file,
  			       struct gendisk *disk, unsigned cmd,
  			       unsigned long arg);

  extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
  extern int blkdev_get(struct block_device *, mode_t, unsigned);
  extern int blkdev_put(struct block_device *);
  extern int bd_claim(struct block_device *, void *);
  extern void bd_release(struct block_device *);

  #ifdef CONFIG_SYSFS
  extern int bd_claim_by_disk(struct block_device *, void *, struct gendisk *);
  extern void bd_release_from_disk(struct block_device *, struct gendisk *);
  #else
  #define bd_claim_by_disk(bdev, holder, disk)	bd_claim(bdev, holder)
  #define bd_release_from_disk(bdev, disk)	bd_release(bdev)
  #endif

  #endif

  
  /* fs/char_dev.c */

  #define CHRDEV_MAJOR_HASH_SIZE	255

  extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
  extern int register_chrdev_region(dev_t, unsigned, const char *);
  extern int register_chrdev(unsigned int, const char *,

  			   const struct file_operations *);

  extern int unregister_chrdev(unsigned int, const char *);
  extern void unregister_chrdev_region(dev_t, unsigned);
  extern int chrdev_open(struct inode *, struct file *);

  extern void chrdev_show(struct seq_file *,off_t);

  
  /* fs/block_dev.c */
  #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */

  
  #ifdef CONFIG_BLOCK
  #define BLKDEV_MAJOR_HASH_SIZE	255

  extern const char *__bdevname(dev_t, char *buffer);
  extern const char *bdevname(struct block_device *bdev, char *buffer);
  extern struct block_device *lookup_bdev(const char *);
  extern struct block_device *open_bdev_excl(const char *, int, void *);
  extern void close_bdev_excl(struct block_device *);

  extern void blkdev_show(struct seq_file *,off_t);

  #else
  #define BLKDEV_MAJOR_HASH_SIZE	0
  #endif

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

  extern const struct file_operations read_fifo_fops;
  extern const struct file_operations write_fifo_fops;
  extern const struct file_operations rdwr_fifo_fops;

  
  extern int fs_may_remount_ro(struct super_block *);

  #ifdef CONFIG_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 __invalidate_device(struct block_device *);

  extern int invalidate_partition(struct gendisk *, int);

  #endif
  extern int invalidate_inodes(struct super_block *);

  unsigned long invalidate_mapping_pages(struct address_space *mapping,
  					pgoff_t start, pgoff_t end);

  static inline unsigned long __deprecated

  invalidate_inode_pages(struct address_space *mapping)
  {
  	return invalidate_mapping_pages(mapping, 0, ~0UL);
  }

  static inline void invalidate_remote_inode(struct inode *inode)
  {
  	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
  	    S_ISLNK(inode->i_mode))

  		invalidate_mapping_pages(inode->i_mapping, 0, -1);

  }
  extern int invalidate_inode_pages2(struct address_space *mapping);
  extern int invalidate_inode_pages2_range(struct address_space *mapping,
  					 pgoff_t start, pgoff_t end);
  extern int write_inode_now(struct inode *, int);
  extern int filemap_fdatawrite(struct address_space *);
  extern int filemap_flush(struct address_space *);
  extern int filemap_fdatawait(struct address_space *);
  extern int filemap_write_and_wait(struct address_space *mapping);
  extern int filemap_write_and_wait_range(struct address_space *mapping,
  				        loff_t lstart, loff_t lend);

  extern int wait_on_page_writeback_range(struct address_space *mapping,
  				pgoff_t start, pgoff_t end);
  extern int __filemap_fdatawrite_range(struct address_space *mapping,
  				loff_t start, loff_t end, int sync_mode);

  extern long do_fsync(struct file *file, int datasync);

  extern void sync_supers(void);
  extern void sync_filesystems(int wait);

  extern void __fsync_super(struct super_block *sb);

  extern void emergency_sync(void);
  extern void emergency_remount(void);
  extern int do_remount_sb(struct super_block *sb, int flags,
  			 void *data, int force);

  #ifdef CONFIG_BLOCK

  extern sector_t bmap(struct inode *, sector_t);

  #endif

  extern int notify_change(struct dentry *, struct iattr *);
  extern int permission(struct inode *, int, struct nameidata *);
  extern int generic_permission(struct inode *, int,
  		int (*check_acl)(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_path.dentry->d_inode->i_writecount);

  }
  extern int do_pipe(int *);

  extern struct file *create_read_pipe(struct file *f);
  extern struct file *create_write_pipe(void);
  extern void free_write_pipe(struct file *);

  extern int open_namei(int dfd, 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 loff_t vfs_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 void generic_drop_inode(struct inode *inode);

  extern struct inode *ilookup5_nowait(struct super_block *sb,
  		unsigned long hashval, int (*test)(struct inode *, void *),
  		void *data);

  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 int __remove_suid(struct dentry *, int);
  extern int should_remove_suid(struct dentry *);

  extern int 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);
  extern void file_kill(struct file *f);

  #ifdef CONFIG_BLOCK

  struct bio;
  extern void submit_bio(int, struct bio *);
  extern int bdev_read_only(struct block_device *);

  #endif

  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 generic_file_readonly_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);

  int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);

  extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);

  extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);

  extern ssize_t generic_file_aio_write_nolock(struct kiocb *, const struct iovec *,

  		unsigned long, loff_t);

  extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
  		unsigned long *, loff_t, loff_t *, size_t, size_t);
  extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
  		unsigned long, loff_t, loff_t *, size_t, ssize_t);
  extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
  extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, 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 *mapping,
  				    struct file_ra_state *, struct file *,
  				    loff_t *, read_descriptor_t *, read_actor_t);

  extern int generic_segment_checks(const struct iovec *iov,
  		unsigned long *nr_segs, size_t *count, int access_flags);

  
  /* fs/splice.c */

  extern ssize_t generic_file_splice_read(struct file *, loff_t *,

  		struct pipe_inode_info *, size_t, unsigned int);
  extern ssize_t generic_file_splice_write(struct pipe_inode_info *,

  		struct file *, loff_t *, size_t, unsigned int);

  extern ssize_t generic_file_splice_write_nolock(struct pipe_inode_info *,
  		struct file *, loff_t *, size_t, unsigned int);

  extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,

  		struct file *out, loff_t *, size_t len, unsigned int flags);
  extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,

  		size_t len, unsigned int flags);

  extern void
  file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);

  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 nonseekable_open(struct inode * inode, struct file * filp);

  #ifdef CONFIG_FS_XIP

  extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
  			     loff_t *ppos);

  extern ssize_t xip_file_sendfile(struct file *in_file, loff_t *ppos,
  				 size_t count, read_actor_t actor,
  				 void *target);
  extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);

  extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
  			      size_t len, loff_t *ppos);

  extern int xip_truncate_page(struct address_space *mapping, loff_t from);

  #else
  static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
  {
  	return 0;
  }

  #endif

  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_mapping,
  				&filp->f_ra,
  				filp,
  				ppos,
  				desc,
  				actor);
  }

  #ifdef CONFIG_BLOCK

  ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
  	struct block_device *bdev, const struct iovec *iov, loff_t offset,

  	unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,

  	int lock_type);
  
  enum {
  	DIO_LOCKING = 1, /* need locking between buffered and direct access */
  	DIO_NO_LOCKING,  /* bdev; no locking at all between buffered/direct */
  	DIO_OWN_LOCKING, /* filesystem locks buffered and direct internally */
  };
  
  static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
  	struct inode *inode, struct block_device *bdev, const struct iovec *iov,

  	loff_t offset, unsigned long nr_segs, get_block_t get_block,

  	dio_iodone_t end_io)
  {
  	return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,

  				nr_segs, get_block, end_io, DIO_LOCKING);

  }
  
  static inline ssize_t blockdev_direct_IO_no_locking(int rw, struct kiocb *iocb,
  	struct inode *inode, struct block_device *bdev, const struct iovec *iov,

  	loff_t offset, unsigned long nr_segs, get_block_t get_block,

  	dio_iodone_t end_io)
  {
  	return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,

  				nr_segs, get_block, end_io, DIO_NO_LOCKING);

  }
  
  static inline ssize_t blockdev_direct_IO_own_locking(int rw, struct kiocb *iocb,
  	struct inode *inode, struct block_device *bdev, const struct iovec *iov,

  	loff_t offset, unsigned long nr_segs, get_block_t get_block,

  	dio_iodone_t end_io)
  {
  	return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,

  				nr_segs, get_block, end_io, DIO_OWN_LOCKING);

  }

  #endif

  extern const struct file_operations generic_ro_fops;

  
  #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
  
  extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
  extern int vfs_follow_link(struct nameidata *, const char *);
  extern int page_readlink(struct dentry *, char __user *, int);

  extern void *page_follow_link_light(struct dentry *, struct nameidata *);
  extern void page_put_link(struct dentry *, struct nameidata *, void *);

  extern int __page_symlink(struct inode *inode, const char *symname, int len,
  		gfp_t gfp_mask);

  extern int page_symlink(struct inode *inode, const char *symname, int len);

  extern const struct inode_operations page_symlink_inode_operations;

  extern int generic_readlink(struct dentry *, char __user *, int);
  extern void generic_fillattr(struct inode *, struct kstat *);
  extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
  void inode_add_bytes(struct inode *inode, loff_t bytes);
  void inode_sub_bytes(struct inode *inode, loff_t bytes);
  loff_t inode_get_bytes(struct inode *inode);
  void inode_set_bytes(struct inode *inode, loff_t bytes);
  
  extern int vfs_readdir(struct file *, filldir_t, void *);
  
  extern int vfs_stat(char __user *, struct kstat *);
  extern int vfs_lstat(char __user *, struct kstat *);

  extern int vfs_stat_fd(int dfd, char __user *, struct kstat *);
  extern int vfs_lstat_fd(int dfd, char __user *, struct kstat *);

  extern int vfs_fstat(unsigned int, struct kstat *);
  
  extern int vfs_ioctl(struct file *, unsigned int, unsigned int, unsigned long);
  
  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_getattr(struct vfsmount *, struct dentry *, struct kstat *);

  extern int simple_statfs(struct dentry *, struct kstatfs *);

  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 *, struct nameidata *);
  extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);

  extern const struct file_operations simple_dir_operations;

  extern const struct inode_operations simple_dir_inode_operations;

  struct tree_descr { char *name; const struct file_operations *ops; int mode; };

  struct dentry *d_alloc_name(struct dentry *, const char *);
  extern int simple_fill_super(struct super_block *, int, struct tree_descr *);

  extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);

  extern void simple_release_fs(struct vfsmount **mount, int *count);
  
  extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t);

  #ifdef CONFIG_MIGRATION

  extern int buffer_migrate_page(struct address_space *,
  				struct page *, struct page *);

  #else
  #define buffer_migrate_page NULL
  #endif

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

  extern void file_update_time(struct file *file);

  
  static inline ino_t parent_ino(struct dentry *dentry)
  {
  	ino_t res;
  
  	spin_lock(&dentry->d_lock);
  	res = dentry->d_parent->d_inode->i_ino;
  	spin_unlock(&dentry->d_lock);
  	return res;
  }
  
  /* kernel/fork.c */
  extern int unshare_files(void);
  
  /* Transaction based IO helpers */
  
  /*
   * An argresp is stored in an allocated page and holds the
   * size of the argument or response, along with its content
   */
  struct simple_transaction_argresp {
  	ssize_t size;
  	char data[0];
  };
  
  #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
  
  char *simple_transaction_get(struct file *file, const char __user *buf,
  				size_t size);
  ssize_t simple_transaction_read(struct file *file, char __user *buf,
  				size_t size, loff_t *pos);
  int simple_transaction_release(struct inode *inode, struct file *file);
  
  static inline void simple_transaction_set(struct file *file, size_t n)
  {
  	struct simple_transaction_argresp *ar = file->private_data;
  
  	BUG_ON(n > SIMPLE_TRANSACTION_LIMIT);
  
  	/*
  	 * The barrier ensures that ar->size will really remain zero until
  	 * ar->data is ready for reading.
  	 */
  	smp_mb();
  	ar->size = n;
  }

  /*
   * simple attribute files
   *
   * These attributes behave similar to those in sysfs:
   *
   * Writing to an attribute immediately sets a value, an open file can be
   * written to multiple times.
   *
   * Reading from an attribute creates a buffer from the value that might get
   * read with multiple read calls. When the attribute has been read
   * completely, no further read calls are possible until the file is opened
   * again.
   *
   * All attributes contain a text representation of a numeric value
   * that are accessed with the get() and set() functions.
   */
  #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
  static int __fops ## _open(struct inode *inode, struct file *file)	\
  {									\
  	__simple_attr_check_format(__fmt, 0ull);			\
  	return simple_attr_open(inode, file, __get, __set, __fmt);	\
  }									\
  static struct file_operations __fops = {				\
  	.owner	 = THIS_MODULE,						\
  	.open	 = __fops ## _open,					\
  	.release = simple_attr_close,					\
  	.read	 = simple_attr_read,					\
  	.write	 = simple_attr_write,					\
  };
  
  static inline void __attribute__((format(printf, 1, 2)))
  __simple_attr_check_format(const char *fmt, ...)
  {
  	/* don't do anything, just let the compiler check the arguments; */
  }
  
  int simple_attr_open(struct inode *inode, struct file *file,
  		     u64 (*get)(void *), void (*set)(void *, u64),
  		     const char *fmt);
  int simple_attr_close(struct inode *inode, struct file *file);
  ssize_t simple_attr_read(struct file *file, char __user *buf,
  			 size_t len, loff_t *ppos);
  ssize_t simple_attr_write(struct file *file, const char __user *buf,
  			  size_t len, loff_t *ppos);

  #ifdef CONFIG_SECURITY
  static inline char *alloc_secdata(void)
  {
  	return (char *)get_zeroed_page(GFP_KERNEL);
  }
  
  static inline void free_secdata(void *secdata)
  {
  	free_page((unsigned long)secdata);
  }
  #else
  static inline char *alloc_secdata(void)
  {
  	return (char *)1;
  }
  
  static inline void free_secdata(void *secdata)
  { }
  #endif	/* CONFIG_SECURITY */
  
  #endif /* __KERNEL__ */
  #endif /* _LINUX_FS_H */