/*

   * fs/f2fs/xattr.h
   *
   * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   *             http://www.samsung.com/
   *
   * Portions of this code from linux/fs/ext2/xattr.h
   *
   * On-disk format of extended attributes for the ext2 filesystem.
   *
   * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #ifndef __F2FS_XATTR_H__
  #define __F2FS_XATTR_H__
  
  #include <linux/init.h>
  #include <linux/xattr.h>
  
  /* Magic value in attribute blocks */
  #define F2FS_XATTR_MAGIC                0xF2F52011
  
  /* Maximum number of references to one attribute block */
  #define F2FS_XATTR_REFCOUNT_MAX         1024
  
  /* Name indexes */

  #define F2FS_SYSTEM_ADVISE_NAME			"system.advise"

  #define F2FS_XATTR_INDEX_USER			1
  #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
  #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3
  #define F2FS_XATTR_INDEX_TRUSTED		4
  #define F2FS_XATTR_INDEX_LUSTRE			5
  #define F2FS_XATTR_INDEX_SECURITY		6
  #define F2FS_XATTR_INDEX_ADVISE			7

  /* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
  #define F2FS_XATTR_INDEX_ENCRYPTION		9
  
  #define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT	"c"

  
  struct f2fs_xattr_header {
  	__le32  h_magic;        /* magic number for identification */
  	__le32  h_refcount;     /* reference count */
  	__u32   h_reserved[4];  /* zero right now */
  };
  
  struct f2fs_xattr_entry {
  	__u8    e_name_index;
  	__u8    e_name_len;
  	__le16  e_value_size;   /* size of attribute value */
  	char    e_name[0];      /* attribute name */
  };
  
  #define XATTR_HDR(ptr)		((struct f2fs_xattr_header *)(ptr))
  #define XATTR_ENTRY(ptr)	((struct f2fs_xattr_entry *)(ptr))

  #define XATTR_FIRST_ENTRY(ptr)	(XATTR_ENTRY(XATTR_HDR(ptr) + 1))

  #define XATTR_ROUND		(3)
  
  #define XATTR_ALIGN(size)	((size + XATTR_ROUND) & ~XATTR_ROUND)
  
  #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
  			entry->e_name_len + le16_to_cpu(entry->e_value_size)))
  
  #define XATTR_NEXT_ENTRY(entry)	((struct f2fs_xattr_entry *)((char *)(entry) +\
  			ENTRY_SIZE(entry)))
  
  #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
  
  #define list_for_each_xattr(entry, addr) \
  		for (entry = XATTR_FIRST_ENTRY(addr);\
  				!IS_XATTR_LAST_ENTRY(entry);\
  				entry = XATTR_NEXT_ENTRY(entry))

  #define MIN_OFFSET(i)	XATTR_ALIGN(inline_xattr_size(i) + PAGE_SIZE -	\
  				sizeof(struct node_footer) - sizeof(__u32))

  #define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
  				sizeof(struct f2fs_xattr_header) -	\
  				sizeof(struct f2fs_xattr_entry))

  /*

   * On-disk structure of f2fs_xattr

   * We use inline xattrs space + 1 block for xattr.

   *
   * +--------------------+
   * | f2fs_xattr_header  |
   * |                    |
   * +--------------------+
   * | f2fs_xattr_entry   |
   * | .e_name_index = 1  |
   * | .e_name_len = 3    |
   * | .e_value_size = 14 |
   * | .e_name = "foo"    |
   * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
   * +--------------------+
   * | f2fs_xattr_entry   |
   * | .e_name_index = 4  |
   * | .e_name = "bar"    |
   * +--------------------+
   * |                    |
   * |        Free        |
   * |                    |
   * +--------------------+<- MIN_OFFSET
   * |   node_footer      |
   * | (nid, ino, offset) |
   * +--------------------+
   *
   **/
  
  #ifdef CONFIG_F2FS_FS_XATTR
  extern const struct xattr_handler f2fs_xattr_user_handler;
  extern const struct xattr_handler f2fs_xattr_trusted_handler;

  extern const struct xattr_handler f2fs_xattr_advise_handler;

  extern const struct xattr_handler f2fs_xattr_security_handler;

  
  extern const struct xattr_handler *f2fs_xattr_handlers[];

  extern int f2fs_setxattr(struct inode *, int, const char *,

  				const void *, size_t, struct page *, int);

  extern int f2fs_getxattr(struct inode *, int, const char *, void *,
  						size_t, struct page *);

  extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);

  #else
  
  #define f2fs_xattr_handlers	NULL

  static inline int f2fs_setxattr(struct inode *inode, int index,

  		const char *name, const void *value, size_t size,
  		struct page *page, int flags)

  {
  	return -EOPNOTSUPP;
  }

  static inline int f2fs_getxattr(struct inode *inode, int index,

  			const char *name, void *buffer,
  			size_t buffer_size, struct page *dpage)

  {
  	return -EOPNOTSUPP;
  }
  static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
  		size_t buffer_size)
  {
  	return -EOPNOTSUPP;
  }
  #endif

  #ifdef CONFIG_F2FS_FS_SECURITY
  extern int f2fs_init_security(struct inode *, struct inode *,
  				const struct qstr *, struct page *);
  #else
  static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
  				const struct qstr *qstr, struct page *ipage)
  {
  	return 0;
  }
  #endif

  #endif /* __F2FS_XATTR_H__ */