/*
   *   fs/cifs/fscache.h - CIFS filesystem cache interface definitions
   *
   *   Copyright (c) 2010 Novell, Inc.
   *   Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
   *
   *   This library is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU Lesser General Public License as published
   *   by the Free Software Foundation; either version 2.1 of the License, or
   *   (at your option) any later version.
   *
   *   This library is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU Lesser General Public License for more details.
   *
   *   You should have received a copy of the GNU Lesser General Public License
   *   along with this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  #ifndef _CIFS_FSCACHE_H
  #define _CIFS_FSCACHE_H
  
  #include <linux/fscache.h>

  #include "cifsglob.h"

  #ifdef CONFIG_CIFS_FSCACHE

  /*

   * Auxiliary data attached to CIFS superblock within the cache
   */
  struct cifs_fscache_super_auxdata {
  	u64	resource_id;		/* unique server resource id */
  	__le64	vol_create_time;
  	u32	vol_serial_number;
  } __packed;
  
  /*

   * Auxiliary data attached to CIFS inode within the cache
   */
  struct cifs_fscache_inode_auxdata {

  	u64 last_write_time_sec;
  	u64 last_change_time_sec;
  	u32 last_write_time_nsec;
  	u32 last_change_time_nsec;
  	u64 eof;

  };
  
  /*
   * cache.c
   */

  extern struct fscache_netfs cifs_fscache_netfs;

  extern const struct fscache_cookie_def cifs_fscache_server_index_def;

  extern const struct fscache_cookie_def cifs_fscache_super_index_def;

  extern const struct fscache_cookie_def cifs_fscache_inode_object_def;

  extern int cifs_fscache_register(void);
  extern void cifs_fscache_unregister(void);

  extern char *extract_sharename(const char *);

  /*
   * fscache.c
   */
  extern void cifs_fscache_get_client_cookie(struct TCP_Server_Info *);
  extern void cifs_fscache_release_client_cookie(struct TCP_Server_Info *);

  extern void cifs_fscache_get_super_cookie(struct cifs_tcon *);
  extern void cifs_fscache_release_super_cookie(struct cifs_tcon *);

  extern void cifs_fscache_release_inode_cookie(struct inode *);
  extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
  extern void cifs_fscache_reset_inode_cookie(struct inode *);

  extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
  extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);

  extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
  extern int __cifs_readpages_from_fscache(struct inode *,
  					 struct address_space *,
  					 struct list_head *,
  					 unsigned *);

  extern void __cifs_fscache_readpages_cancel(struct inode *, struct list_head *);

  extern void __cifs_readpage_to_fscache(struct inode *, struct page *);

  static inline void cifs_fscache_invalidate_page(struct page *page,
  					       struct inode *inode)
  {
  	if (PageFsCache(page))
  		__cifs_fscache_invalidate_page(page, inode);
  }

  static inline int cifs_readpage_from_fscache(struct inode *inode,
  					     struct page *page)
  {
  	if (CIFS_I(inode)->fscache)
  		return __cifs_readpage_from_fscache(inode, page);
  
  	return -ENOBUFS;
  }
  
  static inline int cifs_readpages_from_fscache(struct inode *inode,
  					      struct address_space *mapping,
  					      struct list_head *pages,
  					      unsigned *nr_pages)
  {
  	if (CIFS_I(inode)->fscache)
  		return __cifs_readpages_from_fscache(inode, mapping, pages,
  						     nr_pages);
  	return -ENOBUFS;
  }

  static inline void cifs_readpage_to_fscache(struct inode *inode,
  					    struct page *page)
  {
  	if (PageFsCache(page))
  		__cifs_readpage_to_fscache(inode, page);
  }

  static inline void cifs_fscache_readpages_cancel(struct inode *inode,
  						 struct list_head *pages)
  {
  	if (CIFS_I(inode)->fscache)
  		return __cifs_fscache_readpages_cancel(inode, pages);
  }

  #else /* CONFIG_CIFS_FSCACHE */
  static inline int cifs_fscache_register(void) { return 0; }
  static inline void cifs_fscache_unregister(void) {}

  static inline void
  cifs_fscache_get_client_cookie(struct TCP_Server_Info *server) {}
  static inline void

  cifs_fscache_release_client_cookie(struct TCP_Server_Info *server) {}

  static inline void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon) {}

  static inline void

  cifs_fscache_release_super_cookie(struct cifs_tcon *tcon) {}

  static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
  static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
  						 struct file *filp) {}
  static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}

  static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)

  {
  	return 1; /* May release page */
  }

  static inline void cifs_fscache_invalidate_page(struct page *page,
  			struct inode *inode) {}

  static inline int
  cifs_readpage_from_fscache(struct inode *inode, struct page *page)
  {
  	return -ENOBUFS;
  }
  
  static inline int cifs_readpages_from_fscache(struct inode *inode,
  					      struct address_space *mapping,
  					      struct list_head *pages,
  					      unsigned *nr_pages)
  {
  	return -ENOBUFS;
  }

  static inline void cifs_readpage_to_fscache(struct inode *inode,
  			struct page *page) {}

  static inline void cifs_fscache_readpages_cancel(struct inode *inode,
  						 struct list_head *pages)
  {
  }

  #endif /* CONFIG_CIFS_FSCACHE */
  
  #endif /* _CIFS_FSCACHE_H */