/* -*- linux-c -*- ------------------------------------------------------- *
   *   
   * linux/fs/autofs/autofs_i.h
   *
   *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
   *
   * This file is part of the Linux kernel and is made available under
   * the terms of the GNU General Public License, version 2, or at your
   * option, any later version, incorporated herein by reference.
   *
   * ----------------------------------------------------------------------- */
  
  /* Internal header file for autofs */
  
  #include <linux/auto_fs.h>
  
  /* This is the range of ioctl() numbers we claim as ours */
  #define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
  #define AUTOFS_IOC_COUNT     32
  
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/time.h>
  #include <linux/string.h>
  #include <linux/wait.h>
  #include <linux/dcache.h>
  #include <linux/namei.h>
  #include <linux/mount.h>
  #include <linux/sched.h>
  
  #include <asm/current.h>
  #include <asm/uaccess.h>
  
  #ifdef DEBUG
  #define DPRINTK(D) (printk D)
  #else
  #define DPRINTK(D) ((void)0)
  #endif

  /*
   * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
   * kernel will keep the negative response cached for up to the time given
   * here, although the time can be shorter if the kernel throws the dcache
   * entry away.  This probably should be settable from user space.
   */
  #define AUTOFS_NEGATIVE_TIMEOUT (60*HZ)	/* 1 minute */
  
  /* Structures associated with the root directory hash table */
  
  #define AUTOFS_HASH_SIZE 67
  
  struct autofs_dir_ent {
  	int hash;
  	char *name;
  	int len;
  	ino_t ino;
  	struct dentry *dentry;
  	/* Linked list of entries */
  	struct autofs_dir_ent *next;
  	struct autofs_dir_ent **back;
  	/* The following entries are for the expiry system */
  	unsigned long last_usage;
  	struct list_head exp;
  };
  
  struct autofs_dirhash {
  	struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
  	struct list_head expiry_head;
  };
  
  struct autofs_wait_queue {
  	wait_queue_head_t queue;
  	struct autofs_wait_queue *next;
  	autofs_wqt_t wait_queue_token;
  	/* We use the following to see what we are waiting for */
  	int hash;
  	int len;
  	char *name;
  	/* This is for status reporting upon return */
  	int status;
  	int wait_ctr;
  };
  
  struct autofs_symlink {
  	char *data;
  	int len;
  	time_t mtime;
  };
  
  #define AUTOFS_MAX_SYMLINKS 256
  
  #define AUTOFS_ROOT_INO      1
  #define AUTOFS_FIRST_SYMLINK 2
  #define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)
  
  #define AUTOFS_SYMLINK_BITMAP_LEN \
  	((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8))
  
  #define AUTOFS_SBI_MAGIC 0x6d4a556d
  
  struct autofs_sb_info {
  	u32 magic;
  	struct file *pipe;

  	struct pid *oz_pgrp;

  	int catatonic;

  	struct super_block *sb;

  	unsigned long exp_timeout;
  	ino_t next_dir_ino;
  	struct autofs_wait_queue *queues; /* Wait queue pointer */
  	struct autofs_dirhash dirhash; /* Root directory hash */
  	struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
  	unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
  };
  
  static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
  {
  	return (struct autofs_sb_info *)(sb->s_fs_info);
  }
  
  /* autofs_oz_mode(): do we see the man behind the curtain?  (The
     processes which do manipulations for us in user space sees the raw
     filesystem without "magic".) */
  
  static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {

  	return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;

  }
  
  /* Hash operations */
  
  void autofs_initialize_hash(struct autofs_dirhash *);
  struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
  void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
  void autofs_hash_delete(struct autofs_dir_ent *);
  struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
  void autofs_hash_dputall(struct autofs_dirhash *);

  void autofs_hash_nuke(struct autofs_sb_info *);

  
  /* Expiration-handling functions */
  
  void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
  struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
  
  /* Operations structures */

  extern const struct inode_operations autofs_root_inode_operations;
  extern const struct inode_operations autofs_symlink_inode_operations;

  extern const struct file_operations autofs_root_operations;

  
  /* Initializing function */
  
  int autofs_fill_super(struct super_block *, void *, int);

  void autofs_kill_sb(struct super_block *sb);

  struct inode *autofs_iget(struct super_block *, unsigned long);

  
  /* Queue management functions */
  
  int autofs_wait(struct autofs_sb_info *,struct qstr *);
  int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
  void autofs_catatonic_mode(struct autofs_sb_info *);
  
  #ifdef DEBUG
  void autofs_say(const char *name, int len);
  #else
  #define autofs_say(n,l) ((void)0)
  #endif