#ifndef _LINUX_SEQ_FILE_H
  #define _LINUX_SEQ_FILE_H

  
  #include <linux/types.h>
  #include <linux/string.h>

  #include <linux/bug.h>

  #include <linux/mutex.h>

  #include <linux/cpumask.h>
  #include <linux/nodemask.h>

  
  struct seq_operations;
  struct file;

  struct path;

  struct inode;

  struct dentry;

  struct user_namespace;

  
  struct seq_file {
  	char *buf;
  	size_t size;
  	size_t from;
  	size_t count;

  	size_t pad_until;

  	loff_t index;

  	loff_t read_pos;

  	u64 version;

  	struct mutex lock;

  	const struct seq_operations *op;

  	int poll_event;

  #ifdef CONFIG_USER_NS
  	struct user_namespace *user_ns;
  #endif

  	void *private;
  };
  
  struct seq_operations {
  	void * (*start) (struct seq_file *m, loff_t *pos);
  	void (*stop) (struct seq_file *m, void *v);
  	void * (*next) (struct seq_file *m, void *v, loff_t *pos);
  	int (*show) (struct seq_file *m, void *v);
  };

  #define SEQ_SKIP 1

  /**
   * seq_get_buf - get buffer to write arbitrary data to
   * @m: the seq_file handle
   * @bufp: the beginning of the buffer is stored here
   *
   * Return the number of bytes available in the buffer, or zero if
   * there's no space.
   */
  static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
  {
  	BUG_ON(m->count > m->size);
  	if (m->count < m->size)
  		*bufp = m->buf + m->count;
  	else
  		*bufp = NULL;
  
  	return m->size - m->count;
  }
  
  /**
   * seq_commit - commit data to the buffer
   * @m: the seq_file handle
   * @num: the number of bytes to commit
   *
   * Commit @num bytes of data written to a buffer previously acquired
   * by seq_buf_get.  To signal an error condition, or that the data
   * didn't fit in the available space, pass a negative @num value.
   */
  static inline void seq_commit(struct seq_file *m, int num)
  {
  	if (num < 0) {
  		m->count = m->size;
  	} else {
  		BUG_ON(m->count + num > m->size);
  		m->count += num;
  	}
  }

  /**
   * seq_setwidth - set padding width
   * @m: the seq_file handle
   * @size: the max number of bytes to pad.
   *
   * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
   * finally call seq_pad() to pad the remaining bytes.
   */
  static inline void seq_setwidth(struct seq_file *m, size_t size)
  {
  	m->pad_until = m->count + size;
  }
  void seq_pad(struct seq_file *m, char c);

  char *mangle_path(char *s, const char *p, const char *esc);

  int seq_open(struct file *, const struct seq_operations *);

  ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
  loff_t seq_lseek(struct file *, loff_t, int);
  int seq_release(struct inode *, struct file *);
  int seq_escape(struct seq_file *, const char *, const char *);
  int seq_putc(struct seq_file *m, char c);
  int seq_puts(struct seq_file *m, const char *s);

  int seq_write(struct seq_file *seq, const void *data, size_t len);

  __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);

  __printf(2, 0) int seq_vprintf(struct seq_file *, const char *, va_list args);

  int seq_path(struct seq_file *, const struct path *, const char *);
  int seq_dentry(struct seq_file *, struct dentry *, const char *);
  int seq_path_root(struct seq_file *m, const struct path *path,
  		  const struct path *root, const char *esc);

  int seq_bitmap(struct seq_file *m, const unsigned long *bits,
  				   unsigned int nr_bits);
  static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)

  {

  	return seq_bitmap(m, cpumask_bits(mask), nr_cpu_ids);

  }
  
  static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
  {
  	return seq_bitmap(m, mask->bits, MAX_NUMNODES);
  }

  int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,

  		unsigned int nr_bits);

  static inline int seq_cpumask_list(struct seq_file *m,
  				   const struct cpumask *mask)

  {

  	return seq_bitmap_list(m, cpumask_bits(mask), nr_cpu_ids);

  }
  
  static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
  {
  	return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
  }

  int single_open(struct file *, int (*)(struct seq_file *, void *), void *);

  int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);

  int single_release(struct inode *, struct file *);

  void *__seq_open_private(struct file *, const struct seq_operations *, int);
  int seq_open_private(struct file *, const struct seq_operations *, int);

  int seq_release_private(struct inode *, struct file *);

  int seq_put_decimal_ull(struct seq_file *m, char delimiter,
  			unsigned long long num);

  int seq_put_decimal_ll(struct seq_file *m, char delimiter,
  			long long num);

  static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
  {
  #ifdef CONFIG_USER_NS
  	return seq->user_ns;
  #else
  	extern struct user_namespace init_user_ns;
  	return &init_user_ns;
  #endif
  }

  #define SEQ_START_TOKEN ((void *)1)

  /*
   * Helpers for iteration over list_head-s in seq_files
   */
  
  extern struct list_head *seq_list_start(struct list_head *head,
  		loff_t pos);
  extern struct list_head *seq_list_start_head(struct list_head *head,
  		loff_t pos);
  extern struct list_head *seq_list_next(void *v, struct list_head *head,
  		loff_t *ppos);

  /*
   * Helpers for iteration over hlist_head-s in seq_files
   */
  
  extern struct hlist_node *seq_hlist_start(struct hlist_head *head,

  					  loff_t pos);

  extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,

  					       loff_t pos);

  extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,

  					 loff_t *ppos);
  
  extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
  					      loff_t pos);
  extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
  						   loff_t pos);
  extern struct hlist_node *seq_hlist_next_rcu(void *v,
  						   struct hlist_head *head,
  						   loff_t *ppos);

  
  /* Helpers for iterating over per-cpu hlist_head-s in seq_files */
  extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
  
  extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);

  #endif