/* SPDX-License-Identifier: GPL-2.0 */
  /*
   * dcookies.h
   *
   * Persistent cookie-path mappings
   *
   * Copyright 2002 John Levon <levon@movementarian.org>
   */
  
  #ifndef DCOOKIES_H
  #define DCOOKIES_H
   
  
  #ifdef CONFIG_PROFILING
   
  #include <linux/dcache.h>
  #include <linux/types.h>
   
  struct dcookie_user;
  struct path;
   
  /**
   * dcookie_register - register a user of dcookies
   *
   * Register as a dcookie user. Returns %NULL on failure.
   */
  struct dcookie_user * dcookie_register(void);
  
  /**
   * dcookie_unregister - unregister a user of dcookies
   *
   * Unregister as a dcookie user. This may invalidate
   * any dcookie values returned from get_dcookie().
   */
  void dcookie_unregister(struct dcookie_user * user);
    
  /**
   * get_dcookie - acquire a dcookie
   *
   * Convert the given dentry/vfsmount pair into
   * a cookie value.
   *
   * Returns -EINVAL if no living task has registered as a
   * dcookie user.
   *
   * Returns 0 on success, with *cookie filled in
   */
  int get_dcookie(const struct path *path, unsigned long *cookie);
  
  #else
  
  static inline struct dcookie_user * dcookie_register(void)
  {
  	return NULL;
  }
  
  static inline void dcookie_unregister(struct dcookie_user * user)
  {
  	return;
  }
  
  static inline int get_dcookie(const struct path *path, unsigned long *cookie)
  {
  	return -ENOSYS;
  }
  
  #endif /* CONFIG_PROFILING */
  
  #endif /* DCOOKIES_H */