FreeBSD/Linux Kernel Cross Reference
sys/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/net.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/stddef.h>
    #include <linux/string.h>
    
    #include <asm/atomic.h>
    #include <asm/bitops.h>
    
    struct poll_table_struct;
    
    
    /*
     * 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 FMODE_READ 1
    #define FMODE_WRITE 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_NO_DCACHE    2 /* Only dcache the necessary things. */
    #define FS_NO_PRELIM    4 /* prevent preloading of dentries, even if
                               * FS_NO_DCACHE is not set.
                               */
    #define FS_SINGLE       8 /* Filesystem that can have only one superblock */
    #define FS_NOMOUNT      16 /* Never mount from userland */
    #define FS_LITTER       32 /* Keeps the tree in dcache */
    #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_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_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 */
   
   /*
    * 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_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_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 *);
   extern void update_mctime (struct inode *);
   #define UPDATE_ATIME(inode) update_atime (inode)
   
   extern void buffer_init(unsigned long);
   extern void inode_init(unsigned long);
   extern void mnt_init(unsigned long);
   extern void files_init(unsigned long mempages);
   
   /* bh state bits */
   enum bh_state_bits {
           BH_Uptodate,    /* 1 if the buffer contains valid data */
           BH_Dirty,       /* 1 if the buffer is dirty */
           BH_Lock,        /* 1 if the buffer is locked */
           BH_Req,         /* 0 if the buffer has been invalidated */
           BH_Mapped,      /* 1 if the buffer has a disk mapping */
           BH_New,         /* 1 if the buffer is new and not yet written out */
           BH_Async,       /* 1 if the buffer is under end_buffer_io_async I/O */
           BH_Wait_IO,     /* 1 if we should write out this buffer */
           BH_Launder,     /* 1 if we can throttle on this buffer */
           BH_Attached,    /* 1 if b_inode_buffers is linked into a list */
           BH_JBD,         /* 1 if it has an attached journal_head */
           BH_Sync,        /* 1 if the buffer is a sync read */
   
           BH_PrivateStart,/* not a state bit, but the first bit available
                            * for private allocation by other entities
                            */
   };
   
   #define MAX_BUF_PER_PAGE (PAGE_CACHE_SIZE / 512)
   
   /*
    * Try to keep the most commonly used fields in single cache lines (16
    * bytes) to improve performance.  This ordering should be
    * particularly beneficial on 32-bit processors.
    * 
    * We use the first 16 bytes for the data which is used in searches
    * over the block hash lists (ie. getblk() and friends).
    * 
    * The second 16 bytes we use for lru buffer scans, as used by
    * sync_buffers() and refill_freelist().  -- sct
    */
   struct buffer_head {
           /* First cache line: */
           struct buffer_head *b_next;     /* Hash queue list */
           unsigned long b_blocknr;        /* block number */
           unsigned short b_size;          /* block size */
           unsigned short b_list;          /* List that this buffer appears */
           kdev_t b_dev;                   /* device (B_FREE = free) */
   
           atomic_t b_count;               /* users using this block */
           kdev_t b_rdev;                  /* Real device */
           unsigned long b_state;          /* buffer state bitmap (see above) */
           unsigned long b_flushtime;      /* Time when (dirty) buffer should be written */
   
           struct buffer_head *b_next_free;/* lru/free list linkage */
           struct buffer_head *b_prev_free;/* doubly linked list of buffers */
           struct buffer_head *b_this_page;/* circular list of buffers in one page */
           struct buffer_head *b_reqnext;  /* request queue */
   
           struct buffer_head **b_pprev;   /* doubly linked list of hash-queue */
           char * b_data;                  /* pointer to data block */
           struct page *b_page;            /* the page this bh is mapped to */
           void (*b_end_io)(struct buffer_head *bh, int uptodate); /* I/O completion */
           void *b_private;                /* reserved for b_end_io */
   
           unsigned long b_rsector;        /* Real buffer location on disk */
           wait_queue_head_t b_wait;
   
           struct list_head     b_inode_buffers;   /* doubly linked list of inode dirty buffers */
   };
   
   typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
   void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
   
   #define __buffer_state(bh, state)       (((bh)->b_state & (1UL << BH_##state)) != 0)
   
   #define buffer_uptodate(bh)     __buffer_state(bh,Uptodate)
   #define buffer_dirty(bh)        __buffer_state(bh,Dirty)
   #define buffer_locked(bh)       __buffer_state(bh,Lock)
   #define buffer_req(bh)          __buffer_state(bh,Req)
   #define buffer_mapped(bh)       __buffer_state(bh,Mapped)
   #define buffer_new(bh)          __buffer_state(bh,New)
   #define buffer_async(bh)        __buffer_state(bh,Async)
   #define buffer_launder(bh)      __buffer_state(bh,Launder)
   
   #define bh_offset(bh)           ((unsigned long)(bh)->b_data & ~PAGE_MASK)
   
   extern void set_bh_page(struct buffer_head *bh, struct page *page, unsigned long offset);
   
   #define touch_buffer(bh)        mark_page_accessed(bh->b_page)
   
   
   #include <linux/pipe_fs_i.h>
   #include <linux/minix_fs_i.h>
   #include <linux/ext2_fs_i.h>
   #include <linux/ext3_fs_i.h>
   #include <linux/hpfs_fs_i.h>
   #include <linux/ntfs_fs_i.h>
   #include <linux/msdos_fs_i.h>
   #include <linux/umsdos_fs_i.h>
   #include <linux/iso_fs_i.h>
   #include <linux/nfs_fs_i.h>
   #include <linux/sysv_fs_i.h>
   #include <linux/affs_fs_i.h>
   #include <linux/ufs_fs_i.h>
   #include <linux/efs_fs_i.h>
   #include <linux/coda_fs_i.h>
   #include <linux/romfs_fs_i.h>
   #include <linux/shmem_fs.h>
   #include <linux/smb_fs_i.h>
   #include <linux/hfs_fs_i.h>
   #include <linux/adfs_fs_i.h>
   #include <linux/qnx4_fs_i.h>
   #include <linux/reiserfs_fs_i.h>
   #include <linux/bfs_fs_i.h>
   #include <linux/udf_fs_i.h>
   #include <linux/ncp_fs_i.h>
   #include <linux/proc_fs_i.h>
   #include <linux/usbdev_fs_i.h>
   #include <linux/jffs2_fs_i.h>
   #include <linux/cramfs_fs_sb.h>
   
   /*
    * 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
   
   /*
    * 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;
           time_t          ia_atime;
           time_t          ia_mtime;
           time_t          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 and mount structures.
    */
   #include <linux/quota.h>
   #include <linux/mount.h>
   
   /*
    * oh the beauties of C type declarations.
    */
   struct page;
   struct address_space;
   struct kiobuf;
   
   struct address_space_operations {
           int (*writepage)(struct page *);
           int (*readpage)(struct file *, struct page *);
           int (*sync_page)(struct page *);
           /*
            * 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 */
           int (*bmap)(struct address_space *, long);
           int (*flushpage) (struct page *, unsigned long);
           int (*releasepage) (struct page *, int);
   #define KERNEL_HAS_O_DIRECT /* this is for modules out of the kernel */
           int (*direct_IO)(int, struct inode *, struct kiobuf *, unsigned long, int);
   #define KERNEL_HAS_DIRECT_FILEIO /* Unfortunate kludge due to lack of foresight */
           int (*direct_fileIO)(int, struct file *, struct kiobuf *, unsigned long, int);
           void (*removepage)(struct page *); /* called when page gets removed from the inode */
   };
   
   struct address_space {
           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 */
           unsigned long           nrpages;        /* number of total pages */
           struct address_space_operations *a_ops; /* methods */
           struct inode            *host;          /* owner: inode, block_device */
           struct vm_area_struct   *i_mmap;        /* list of private mappings */
           struct vm_area_struct   *i_mmap_shared; /* list of shared mappings */
           spinlock_t              i_shared_lock;  /* and spinlock protecting it */
           int                     gfp_mask;       /* how to allocate the pages */
   };
   
   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;
           const struct block_device_operations *bd_op;
           struct semaphore        bd_sem; /* open/close mutex */
           struct list_head        bd_inodes;
   };
   
   struct inode {
           struct list_head        i_hash;
           struct list_head        i_list;
           struct list_head        i_dentry;
           
           struct list_head        i_dirty_buffers;
           struct list_head        i_dirty_data_buffers;
   
           unsigned long           i_ino;
           atomic_t                i_count;
           kdev_t                  i_dev;
           umode_t                 i_mode;
           nlink_t                 i_nlink;
           uid_t                   i_uid;
           gid_t                   i_gid;
           kdev_t                  i_rdev;
           loff_t                  i_size;
           time_t                  i_atime;
           time_t                  i_mtime;
           time_t                  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 rw_semaphore     i_alloc_sem;
           struct semaphore        i_zombie;
           struct inode_operations *i_op;
           struct file_operations  *i_fop; /* former ->i_op->default_file_ops */
           struct super_block      *i_sb;
           wait_queue_head_t       i_wait;
           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;
           unsigned int            i_attr_flags;
           __u32                   i_generation;
           union {
                   struct minix_inode_info         minix_i;
                   struct ext2_inode_info          ext2_i;
                   struct ext3_inode_info          ext3_i;
                   struct hpfs_inode_info          hpfs_i;
                   struct ntfs_inode_info          ntfs_i;
                   struct msdos_inode_info         msdos_i;
                   struct umsdos_inode_info        umsdos_i;
                   struct iso_inode_info           isofs_i;
                   struct nfs_inode_info           nfs_i;
                   struct sysv_inode_info          sysv_i;
                   struct affs_inode_info          affs_i;
                   struct ufs_inode_info           ufs_i;
                   struct efs_inode_info           efs_i;
                   struct romfs_inode_info         romfs_i;
                   struct shmem_inode_info         shmem_i;
                   struct coda_inode_info          coda_i;
                   struct smb_inode_info           smbfs_i;
                   struct hfs_inode_info           hfs_i;
                   struct adfs_inode_info          adfs_i;
                   struct qnx4_inode_info          qnx4_i;
                   struct reiserfs_inode_info      reiserfs_i;
                   struct bfs_inode_info           bfs_i;
                   struct udf_inode_info           udf_i;
                   struct ncp_inode_info           ncpfs_i;
                   struct proc_inode_info          proc_i;
                   struct socket                   socket_i;
                   struct usbdev_inode_info        usbdev_i;
                   struct jffs2_inode_info         jffs2_i;
                   void                            *generic_ip;
           } u;
   };
   
   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;
   }
   
   struct fown_struct {
           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 */
   };
   
   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;
           unsigned long           f_reada, f_ramax, f_raend, f_ralen, f_rawin;
           struct fown_struct      f_owner;
           unsigned int            f_uid, f_gid;
           int                     f_error;
   
           unsigned long           f_version;
   
           /* needed for tty driver, and maybe others */
           void                    *private_data;
   
           /* preallocated helper kiobuf to speedup O_DIRECT */
           struct kiobuf           *f_iobuf;
           long                    f_iobuf_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_BROKEN       4       /* broken flock() emulation */
   #define FL_ACCESS       8       /* for processes suspended by mandatory locking */
   #define FL_LOCKD        16      /* lock held by rpc.lockd */
   #define FL_LEASE        32      /* lease held on this file */
   
   /*
    * 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 {
           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(unsigned int, struct flock *);
   extern int fcntl_setlk(unsigned int, unsigned int, struct flock *);
   
   extern int fcntl_getlk64(unsigned int, struct flock64 *);
   extern int fcntl_setlk64(unsigned int, 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 *, unsigned int);
   extern void posix_block_lock(struct file_lock *, struct file_lock *);
   extern void posix_unblock_lock(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 time_t lease_get_mtime(struct inode *);
   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);
   extern void steal_locks(fl_owner_t from);
   
   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);
   
   struct nameidata {
           struct dentry *dentry;
           struct vfsmount *mnt;
           struct qstr last;
           unsigned int flags;
           int last_type;
   };
   
   /*
    *      Umount options
    */
   
   #define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
   #define MNT_DETACH      0x00000002      /* Just detach from the tree */
   
   #include <linux/minix_fs_sb.h>
   #include <linux/ext2_fs_sb.h>
   #include <linux/ext3_fs_sb.h>
   #include <linux/hpfs_fs_sb.h>
   #include <linux/ntfs_fs_sb.h>
   #include <linux/msdos_fs_sb.h>
   #include <linux/iso_fs_sb.h>
   #include <linux/nfs_fs_sb.h>
   #include <linux/sysv_fs_sb.h>
   #include <linux/affs_fs_sb.h>
   #include <linux/ufs_fs_sb.h>
   #include <linux/efs_fs_sb.h>
   #include <linux/romfs_fs_sb.h>
   #include <linux/smb_fs_sb.h>
   #include <linux/hfs_fs_sb.h>
   #include <linux/adfs_fs_sb.h>
   #include <linux/qnx4_fs_sb.h>
   #include <linux/reiserfs_fs_sb.h>
   #include <linux/bfs_fs_sb.h>
   #include <linux/udf_fs_sb.h>
   #include <linux/ncp_fs_sb.h>
   #include <linux/usbdev_fs_sb.h>
   #include <linux/cramfs_fs_sb.h>
   #include <linux/jffs2_fs_sb.h>
   
   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 */
           kdev_t                  s_dev;
           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;
           struct super_operations *s_op;
           struct dquot_operations *dq_op;
           struct quotactl_ops     *s_qcop;
           unsigned long           s_flags;
           unsigned long           s_magic;
           struct dentry           *s_root;
           struct rw_semaphore     s_umount;
           struct semaphore        s_lock;
           int                     s_count;
           atomic_t                s_active;
   
           struct list_head        s_dirty;        /* dirty inodes */
           struct list_head        s_locked_inodes;/* inodes being synced */
           struct list_head        s_files;
   
           struct block_device     *s_bdev;
           struct list_head        s_instances;
           struct quota_info       s_dquot;        /* Diskquota specific options */
   
           union {
                   struct minix_sb_info    minix_sb;
                   struct ext2_sb_info     ext2_sb;
                   struct ext3_sb_info     ext3_sb;
                   struct hpfs_sb_info     hpfs_sb;
                   struct ntfs_sb_info     ntfs_sb;
                   struct msdos_sb_info    msdos_sb;
                   struct isofs_sb_info    isofs_sb;
                   struct nfs_sb_info      nfs_sb;
                   struct sysv_sb_info     sysv_sb;
                   struct affs_sb_info     affs_sb;
                   struct ufs_sb_info      ufs_sb;
                   struct efs_sb_info      efs_sb;
                   struct shmem_sb_info    shmem_sb;
                   struct romfs_sb_info    romfs_sb;
                   struct smb_sb_info      smbfs_sb;
                   struct hfs_sb_info      hfs_sb;
                   struct adfs_sb_info     adfs_sb;
                   struct qnx4_sb_info     qnx4_sb;
                   struct reiserfs_sb_info reiserfs_sb;
                   struct bfs_sb_info      bfs_sb;
                   struct udf_sb_info      udf_sb;
                   struct ncp_sb_info      ncpfs_sb;
                   struct usbdev_sb_info   usbdevfs_sb;
                   struct jffs2_sb_info    jffs2_sb;
                   struct cramfs_sb_info   cramfs_sb;
                   void                    *generic_sbp;
           } u;
           /*
            * 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 */
   
           /* The next field is used by knfsd when converting a (inode number based)
            * file handle into a dentry. As it builds a path in the dcache tree from
            * the bottom up, there may for a time be a subpath of dentrys which is not
            * connected to the main tree.  This semaphore ensure that there is only ever
            * one such free path per filesystem.  Note that unconnected files (or other
            * non-directories) are allowed, but not unconnected diretories.
            */
           struct semaphore s_nfsd_free_path_sem;
   };
   
   /*
    * 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
    */
   #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 (*check_media_change) (kdev_t);
           int (*revalidate) (kdev_t);
           struct module *owner;
   };
   
   /*
    * NOTE:
    * read, write, poll, fsync, readv, writev 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 *, size_t, loff_t *);
           ssize_t (*write) (struct file *, 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 (*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 (*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 (*revalidate) (struct dentry *);
           int (*setattr) (struct dentry *, struct iattr *);
           int (*getattr) (struct dentry *, struct iattr *);
           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;
   
   /*
    * 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 *);
     
           /* reiserfs kludge.  reiserfs needs 64 bits of information to
           ** find an inode.  We are using the read_inode2 call to get
           ** that information.  We don't like this, and are waiting on some
           ** VFS changes for the real solution.
           ** iget4 calls read_inode2, iff it is defined
           */
           void (*read_inode2) (struct inode *, void *) ;
           void (*dirty_inode) (struct inode *);
           void (*write_inode) (struct inode *, int);
           void (*put_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 *);
           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 *);
   
           /* Following are for knfsd to interact with "interesting" filesystems
            * Currently just reiserfs, but possibly FAT and others later
            *
            * fh_to_dentry is given a filehandle fragement with length, and a type flag
            *   and must return a dentry for the referenced object or, if "parent" is
            *   set, a dentry for the parent of the object.
            *   If a dentry cannot be found, a "root" dentry should be created and
            *   flaged as DCACHE_NFSD_DISCONNECTED. nfsd_iget is an example implementation.
            *
            * dentry_to_fh is given a dentry and must generate the filesys specific
            *   part of the file handle.  Available length is passed in *lenp and used
            *   length should be returned therein.
            *   If need_parent is set, then dentry_to_fh should encode sufficient information
            *   to find the (current) parent.
            *   dentry_to_fh should return a 1byte "type" which will be passed back in
            *   the fhtype arguement to fh_to_dentry.  Type of 0 is reserved.
            *   If filesystem was exportable before the introduction of fh_to_dentry,
            *   types 1 and 2 should be used is that same way as the generic code.
            *   Type 255 means error.
            *
            * Lengths are in units of 4bytes, not bytes.
            */
           struct dentry * (*fh_to_dentry)(struct super_block *sb, __u32 *fh, int len, int fhtype, int parent);
           int (*dentry_to_fh)(struct dentry *, __u32 *fh, int *lenp, int need_parent);
           int (*show_options)(struct seq_file *, struct vfsmount *);
   };
   
   /* Inode state bits.. */
   #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_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 mark_inode_dirty_pages(struct inode *inode)
   {
           __mark_inode_dirty(inode, I_DIRTY_PAGES);
   }
   
   struct file_system_type {
           const char *name;
           int fs_flags;
           struct super_block *(*read_super) (struct super_block *, void *, int);
           struct module *owner;
           struct file_system_type * next;
           struct list_head fs_supers;
   };
   
   #define DECLARE_FSTYPE(var,type,read,flags) \
   struct file_system_type var = { \
          name:           type, \
          read_super:     read, \
          fs_flags:       flags, \
          owner:          THIS_MODULE, \
  }
  
  #define DECLARE_FSTYPE_DEV(var,type,read) \
          DECLARE_FSTYPE(var,type,read,FS_REQUIRES_DEV)
  
  /* 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)
                  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_get(struct block_device *, mode_t, unsigned, int);
  extern int blkdev_put(struct block_device *, int);
  
  /* fs/devices.c */
  extern const struct block_device_operations *get_blkfops(unsigned int);
  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(kdev_t);
  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 *);
  
  extern int FASTCALL(try_to_free_buffers(struct page *, unsigned int));
  extern void refile_buffer(struct buffer_head * buf);
  extern void create_empty_buffers(struct page *, kdev_t, unsigned long);
  extern void end_buffer_io_sync(struct buffer_head *bh, int uptodate);
  
  /* reiserfs_writepage needs this */
  extern void set_buffer_async_io(struct buffer_head *bh) ;
  
  #define BUF_CLEAN       0
  #define BUF_LOCKED      1       /* Buffers scheduled for write */
  #define BUF_DIRTY       2       /* Dirty buffers, not yet scheduled for write */
  #define NR_LIST         3
  
  static inline void get_bh(struct buffer_head * bh)
  {
          atomic_inc(&(bh)->b_count);
  }
  
  static inline void put_bh(struct buffer_head *bh)
  {
          smp_mb__before_atomic_dec();
          atomic_dec(&bh->b_count);
  }
  
  /*
   * This is called by bh->b_end_io() handlers when I/O has completed.
   */
  static inline void mark_buffer_uptodate(struct buffer_head * bh, int on)
  {
          if (on)
                  set_bit(BH_Uptodate, &bh->b_state);
          else
                  clear_bit(BH_Uptodate, &bh->b_state);
  }
  
  #define atomic_set_buffer_clean(bh) test_and_clear_bit(BH_Dirty, &(bh)->b_state)
  
  static inline void __mark_buffer_clean(struct buffer_head *bh)
  {
          refile_buffer(bh);
  }
  
  static inline void mark_buffer_clean(struct buffer_head * bh)
  {
          if (atomic_set_buffer_clean(bh))
                  __mark_buffer_clean(bh);
  }
  
  extern void FASTCALL(__mark_dirty(struct buffer_head *bh));
  extern void FASTCALL(__mark_buffer_dirty(struct buffer_head *bh));
  extern void FASTCALL(mark_buffer_dirty(struct buffer_head *bh));
  
  extern void FASTCALL(buffer_insert_list(struct buffer_head *, struct list_head *));
  
  static inline void buffer_insert_inode_queue(struct buffer_head *bh, struct inode *inode)
  {
          buffer_insert_list(bh, &inode->i_dirty_buffers);
  }
  
  static inline void buffer_insert_inode_data_queue(struct buffer_head *bh, struct inode *inode)
  {
          buffer_insert_list(bh, &inode->i_dirty_data_buffers);
  }
  
  static inline int atomic_set_buffer_dirty(struct buffer_head *bh)
  {
          return test_and_set_bit(BH_Dirty, &bh->b_state);
  }
  
  static inline void mark_buffer_async(struct buffer_head * bh, int on)
  {
          if (on)
                  set_bit(BH_Async, &bh->b_state);
          else
                  clear_bit(BH_Async, &bh->b_state);
  }
  
  static inline void set_buffer_attached(struct buffer_head *bh)
  {
          set_bit(BH_Attached, &bh->b_state);
  }
  
  static inline void clear_buffer_attached(struct buffer_head *bh)
  {
          clear_bit(BH_Attached, &bh->b_state);
  }
  
  static inline int buffer_attached(struct buffer_head *bh)
  {
          return test_bit(BH_Attached, &bh->b_state);
  }
  
  /*
   * If an error happens during the make_request, this function
   * has to be recalled. It marks the buffer as clean and not
   * uptodate, and it notifys the upper layer about the end
   * of the I/O.
   */
  static inline void buffer_IO_error(struct buffer_head * bh)
  {
          mark_buffer_clean(bh);
          /*
           * b_end_io has to clear the BH_Uptodate bitflag in the error case!
           */
          bh->b_end_io(bh, 0);
  }
  
  static inline void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode)
  {
          mark_buffer_dirty(bh);
          buffer_insert_inode_queue(bh, inode);
  }
  
  extern void set_buffer_flushtime(struct buffer_head *);
  extern void balance_dirty(void);
  extern int check_disk_change(kdev_t);
  extern int invalidate_inodes(struct super_block *);
  extern int invalidate_device(kdev_t, int);
  extern void invalidate_inode_pages(struct inode *);
  extern void invalidate_inode_pages2(struct address_space *);
  extern void invalidate_inode_buffers(struct inode *);
  #define invalidate_buffers(dev) __invalidate_buffers((dev), 0)
  #define destroy_buffers(dev)    __invalidate_buffers((dev), 1)
  extern void invalidate_bdev(struct block_device *, int);
  extern void __invalidate_buffers(kdev_t dev, int);
  extern void sync_inodes(kdev_t);
  extern void sync_unlocked_inodes(void);
  extern void write_inode_now(struct inode *, int);
  extern int sync_buffers(kdev_t, int);
  extern void sync_dev(kdev_t);
  extern int fsync_dev(kdev_t);
  extern int fsync_super(struct super_block *);
  extern int fsync_no_super(kdev_t);
  extern void sync_inodes_sb(struct super_block *);
  extern int fsync_buffers_list(struct list_head *);
  static inline int fsync_inode_buffers(struct inode *inode)
  {
          return fsync_buffers_list(&inode->i_dirty_buffers);
  }
  static inline int fsync_inode_data_buffers(struct inode *inode)
  {
          return fsync_buffers_list(&inode->i_dirty_data_buffers);
  }
  extern int inode_has_buffers(struct inode *);
  extern int do_fdatasync(struct file *);
  extern int filemap_fdatasync(struct address_space *);
  extern int filemap_fdatawait(struct address_space *);
  extern void sync_supers(kdev_t dev, int wait);
  extern int bmap(struct inode *, 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 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 *);
  
  /*
   * Kernel pointers have redundant information, so we can use a
   * scheme where we can return either an error code or a dentry
   * pointer with the same return value.
   *
   * This should be a per-architecture thing, to allow different
   * error and pointer decisions.
   */
  static inline void *ERR_PTR(long error)
  {
          return (void *) error;
  }
  
  static inline long PTR_ERR(const void *ptr)
  {
          return (long) ptr;
  }
  
  static inline long IS_ERR(const void *ptr)
  {
          return (unsigned long)ptr > (unsigned long)-1000L;
  }
  
  /*
   * The bitmask for a lookup event:
   *  - follow links at the end
   *  - require a directory
   *  - ending slashes ok even for nonexistent files
   *  - internal "there are more path compnents" flag
   */
  #define LOOKUP_FOLLOW           (1)
  #define LOOKUP_DIRECTORY        (2)
  #define LOOKUP_CONTINUE         (4)
  #define LOOKUP_POSITIVE         (8)
  #define LOOKUP_PARENT           (16)
  #define LOOKUP_NOALT            (32)
  /*
   * Type of the last component on LOOKUP_PARENT
   */
  enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  
  /*
   * "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);
  
  /* needed for stackable file system support */
  extern loff_t default_llseek(struct file *file, loff_t offset, int origin);
  
  extern int FASTCALL(__user_walk(const char *, unsigned, struct nameidata *));
  extern int FASTCALL(path_init(const char *, unsigned, struct nameidata *));
  extern int FASTCALL(path_walk(const char *, struct nameidata *));
  extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *));
  extern int FASTCALL(link_path_walk(const char *, struct nameidata *));
  extern void path_release(struct nameidata *);
  extern int follow_down(struct vfsmount **, struct dentry **);
  extern int follow_up(struct vfsmount **, struct dentry **);
  extern struct dentry * lookup_one_len(const char *, struct dentry *, int);
  extern struct dentry * lookup_hash(struct qstr *, struct dentry *);
  #define user_path_walk(name,nd)  __user_walk(name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, nd)
  #define user_path_walk_link(name,nd) __user_walk(name, LOOKUP_POSITIVE, nd)
  
  extern void inode_init_once(struct inode *);
  extern void iput(struct inode *);
  extern void force_delete(struct inode *);
  extern struct inode * igrab(struct inode *);
  extern ino_t iunique(struct super_block *, ino_t);
  
  typedef int (*find_inode_t)(struct inode *, unsigned long, void *);
  extern struct inode * iget4(struct super_block *, unsigned long, find_inode_t, void *);
  static inline struct inode *iget(struct super_block *sb, unsigned long ino)
  {
          return iget4(sb, ino, NULL, NULL);
  }
  
  extern void clear_inode(struct inode *);
  extern struct inode *new_inode(struct super_block *sb);
  extern void remove_suid(struct inode *inode);
  
  extern void insert_inode_hash(struct inode *);
  extern void remove_inode_hash(struct inode *);
  extern struct file * get_empty_filp(void);
  extern void file_move(struct file *f, struct list_head *list);
  extern struct buffer_head * get_hash_table(kdev_t, int, int);
  extern struct buffer_head * getblk(kdev_t, int, int);
  extern void ll_rw_block(int, int, struct buffer_head * bh[]);
  extern void submit_bh(int, struct buffer_head *);
  extern int is_read_only(kdev_t);
  extern void __brelse(struct buffer_head *);
  static inline void brelse(struct buffer_head *buf)
  {
          if (buf)
                  __brelse(buf);
  }
  extern void __bforget(struct buffer_head *);
  static inline void bforget(struct buffer_head *buf)
  {
          if (buf)
                  __bforget(buf);
  }
  extern int set_blocksize(kdev_t, int);
  extern int sb_set_blocksize(struct super_block *, int);
  extern int sb_min_blocksize(struct super_block *, int);
  extern struct buffer_head * bread(kdev_t, int, int);
  static inline struct buffer_head * sb_bread(struct super_block *sb, int block)
  {
          return bread(sb->s_dev, block, sb->s_blocksize);
  }
  static inline struct buffer_head * sb_getblk(struct super_block *sb, int block)
  {
          return getblk(sb->s_dev, block, sb->s_blocksize);
  }
  static inline struct buffer_head * sb_get_hash_table(struct super_block *sb, int block)
  {
          return get_hash_table(sb->s_dev, block, sb->s_blocksize);
  }
  extern void wakeup_bdflush(void);
  extern void put_unused_buffer_head(struct buffer_head * bh);
  extern struct buffer_head * get_unused_buffer_head(int async);
  
  extern int brw_page(int, struct page *, kdev_t, int [], int);
  
  typedef int (get_block_t)(struct inode*,long,struct buffer_head*,int);
  
  /* Generic buffer handling for block filesystems.. */
  extern int try_to_release_page(struct page * page, int gfp_mask);
  extern int discard_bh_page(struct page *, unsigned long, int);
  #define block_flushpage(page, offset) discard_bh_page(page, offset, 1)
  #define block_invalidate_page(page) discard_bh_page(page, 0, 0)
  extern int block_symlink(struct inode *, const char *, int);
  extern int block_write_full_page(struct page*, get_block_t*);
  extern int block_read_full_page(struct page*, get_block_t*);
  extern int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*);
  extern int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*,
                                  unsigned long *);
  extern int generic_cont_expand(struct inode *inode, loff_t size) ;
  extern int block_commit_write(struct page *page, unsigned from, unsigned to);
  extern int block_sync_page(struct page *);
  
  int generic_block_bmap(struct address_space *, long, get_block_t *);
  int generic_commit_write(struct file *, struct page *, unsigned, unsigned);
  int block_truncate_page(struct address_space *, loff_t, get_block_t *);
  extern int generic_direct_IO(int, struct inode *, struct kiobuf *, unsigned long, int, get_block_t *);
  extern int waitfor_one_page(struct page *);
  extern int writeout_one_page(struct page *);
  
  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 ssize_t generic_file_read(struct file *, char *, size_t, loff_t *);
  extern int precheck_file_write(struct file *, struct inode *, size_t *, loff_t *);
  extern ssize_t generic_file_write(struct file *, const char *, size_t, loff_t *);
  extern void do_generic_file_read(struct file *, loff_t *, read_descriptor_t *, read_actor_t);
  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 ssize_t generic_read_dir(struct file *, char *, size_t, loff_t *);
  extern int generic_file_open(struct inode * inode, struct file * filp);
  
  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 struct inode_operations page_symlink_inode_operations;
  
  extern int vfs_readdir(struct file *, filldir_t, void *);
  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_dir_fsync(struct file *, struct dentry *, int);
  extern int dcache_readdir(struct file *, void *, filldir_t);
  extern struct file_operations dcache_dir_ops;
  
  extern struct file_system_type *get_fs_type(const char *name);
  extern struct super_block *get_super(kdev_t);
  extern void drop_super(struct super_block *sb);
  static inline int is_mounted(kdev_t dev)
  {
          struct super_block *sb = get_super(dev);
          if (sb) {
                  drop_super(sb);
                  return 1;
          }
          return 0;
  }
  unsigned long generate_cluster(kdev_t, int b[], int);
  unsigned long generate_cluster_swab32(kdev_t, int b[], int);
  extern kdev_t ROOT_DEV;
  extern char root_device_name[];
  
  
  extern void show_buffers(void);
  
  #ifdef CONFIG_BLK_DEV_INITRD
  extern unsigned int real_root_dev;
  #endif
  
  extern ssize_t char_read(struct file *, char *, size_t, loff_t *);
  extern ssize_t block_read(struct file *, char *, size_t, loff_t *);
  extern int read_ahead[];
  
  extern ssize_t char_write(struct file *, const char *, size_t, loff_t *);
  extern ssize_t block_write(struct file *, const char *, size_t, loff_t *);
  
  extern int file_fsync(struct file *, struct dentry *, int);
  extern int generic_buffer_fdatasync(struct inode *inode, unsigned long start_idx, unsigned long end_idx);
  extern int generic_osync_inode(struct inode *, int);
  #define OSYNC_METADATA (1<<0)
  #define OSYNC_DATA (1<<1)
  #define OSYNC_INODE (1<<2)
  
  extern int inode_change_ok(struct inode *, struct iattr *);
  extern int inode_setattr(struct inode *, struct iattr *);
  
  /* kernel/fork.c */
  extern int unshare_files(void);
  
  /*
   * Common dentry functions for inclusion in the VFS
   * or in other stackable file systems.  Some of these
   * functions were in linux/fs/ C (VFS) files.
   *
   */
  
  /*
   * Locking the parent is needed to:
   *  - serialize directory operations
   *  - make sure the parent doesn't change from
   *    under us in the middle of an operation.
   *
   * NOTE! Right now we'd rather use a "struct inode"
   * for this, but as I expect things to move toward
   * using dentries instead for most things it is
   * probably better to start with the conceptually
   * better interface of relying on a path of dentries.
   */
  static inline struct dentry *lock_parent(struct dentry *dentry)
  {
          struct dentry *dir = dget(dentry->d_parent);
  
          down(&dir->d_inode->i_sem);
          return dir;
  }
  
  static inline struct dentry *get_parent(struct dentry *dentry)
  {
          return dget(dentry->d_parent);
  }
  
  static inline void unlock_dir(struct dentry *dir)
  {
          up(&dir->d_inode->i_sem);
          dput(dir);
  }
  
  /*
   * Whee.. Deadlock country. Happily there are only two VFS
   * operations that does this..
   */
  static inline void double_down(struct semaphore *s1, struct semaphore *s2)
  {
          if (s1 != s2) {
                  if ((unsigned long) s1 < (unsigned long) s2) {
                          struct semaphore *tmp = s2;
                          s2 = s1; s1 = tmp;
                  }
                  down(s1);
          }
          down(s2);
  }
  
  /*
   * Ewwwwwwww... _triple_ lock. We are guaranteed that the 3rd argument is
   * not equal to 1st and not equal to 2nd - the first case (target is parent of
   * source) would be already caught, the second is plain impossible (target is
   * its own parent and that case would be caught even earlier). Very messy.
   * I _think_ that it works, but no warranties - please, look it through.
   * Pox on bloody lusers who mandated overwriting rename() for directories...
   */
  
  static inline void triple_down(struct semaphore *s1,
                                 struct semaphore *s2,
                                 struct semaphore *s3)
  {
          if (s1 != s2) {
                  if ((unsigned long) s1 < (unsigned long) s2) {
                          if ((unsigned long) s1 < (unsigned long) s3) {
                                  struct semaphore *tmp = s3;
                                  s3 = s1; s1 = tmp;
                          }
                          if ((unsigned long) s1 < (unsigned long) s2) {
                                  struct semaphore *tmp = s2;
                                  s2 = s1; s1 = tmp;
                          }
                  } else {
                          if ((unsigned long) s1 < (unsigned long) s3) {
                                  struct semaphore *tmp = s3;
                                  s3 = s1; s1 = tmp;
                          }
                          if ((unsigned long) s2 < (unsigned long) s3) {
                                  struct semaphore *tmp = s3;
                                  s3 = s2; s2 = tmp;
                          }
                  }
                  down(s1);
          } else if ((unsigned long) s2 < (unsigned long) s3) {
                  struct semaphore *tmp = s3;
                  s3 = s2; s2 = tmp;
          }
          down(s2);
          down(s3);
  }
  
  static inline void double_up(struct semaphore *s1, struct semaphore *s2)
  {
          up(s1);
          if (s1 != s2)
                  up(s2);
  }
  
  static inline void triple_up(struct semaphore *s1,
                               struct semaphore *s2,
                               struct semaphore *s3)
  {
          up(s1);
          if (s1 != s2)
                  up(s2);
          up(s3);
  }
  
  static inline void double_lock(struct dentry *d1, struct dentry *d2)
  {
          double_down(&d1->d_inode->i_sem, &d2->d_inode->i_sem);
  }
  
  static inline void double_unlock(struct dentry *d1, struct dentry *d2)
  {
          double_up(&d1->d_inode->i_sem,&d2->d_inode->i_sem);
          dput(d1);
          dput(d2);
  }
  
  #endif /* __KERNEL__ */
  
  #endif /* _LINUX_FS_H */

Cache object: 31e01782ee1b1a6d746f4e638d4286fb