/* SPDX-License-Identifier: GPL-2.0 */

  /*
    File: linux/ext2_xattr.h
  
    On-disk format of extended attributes for the ext2 filesystem.
  
    (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
  */

  #include <linux/init.h>
  #include <linux/xattr.h>
  
  /* Magic value in attribute blocks */
  #define EXT2_XATTR_MAGIC		0xEA020000
  
  /* Maximum number of references to one attribute block */
  #define EXT2_XATTR_REFCOUNT_MAX		1024
  
  /* Name indexes */
  #define EXT2_XATTR_INDEX_USER			1
  #define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS	2
  #define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT	3
  #define EXT2_XATTR_INDEX_TRUSTED		4
  #define	EXT2_XATTR_INDEX_LUSTRE			5
  #define EXT2_XATTR_INDEX_SECURITY	        6
  
  struct ext2_xattr_header {
  	__le32	h_magic;	/* magic number for identification */
  	__le32	h_refcount;	/* reference count */
  	__le32	h_blocks;	/* number of disk blocks used */
  	__le32	h_hash;		/* hash value of all attributes */
  	__u32	h_reserved[4];	/* zero right now */
  };
  
  struct ext2_xattr_entry {
  	__u8	e_name_len;	/* length of name */
  	__u8	e_name_index;	/* attribute name index */
  	__le16	e_value_offs;	/* offset in disk block of value */
  	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
  	__le32	e_value_size;	/* size of attribute value */
  	__le32	e_hash;		/* hash value of name and value */
  	char	e_name[0];	/* attribute name */
  };
  
  #define EXT2_XATTR_PAD_BITS		2
  #define EXT2_XATTR_PAD		(1<<EXT2_XATTR_PAD_BITS)
  #define EXT2_XATTR_ROUND		(EXT2_XATTR_PAD-1)
  #define EXT2_XATTR_LEN(name_len) \
  	(((name_len) + EXT2_XATTR_ROUND + \
  	sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
  #define EXT2_XATTR_NEXT(entry) \
  	( (struct ext2_xattr_entry *)( \
  	  (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
  #define EXT2_XATTR_SIZE(size) \
  	(((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)

  struct mb_cache;

  # ifdef CONFIG_EXT2_FS_XATTR

  extern const struct xattr_handler ext2_xattr_user_handler;
  extern const struct xattr_handler ext2_xattr_trusted_handler;

  extern const struct xattr_handler ext2_xattr_security_handler;

  
  extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
  
  extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
  extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  
  extern void ext2_xattr_delete_inode(struct inode *);

  extern struct mb_cache *ext2_xattr_create_cache(void);
  extern void ext2_xattr_destroy_cache(struct mb_cache *cache);

  extern const struct xattr_handler *ext2_xattr_handlers[];

  
  # else  /* CONFIG_EXT2_FS_XATTR */
  
  static inline int
  ext2_xattr_get(struct inode *inode, int name_index,
  	       const char *name, void *buffer, size_t size)
  {
  	return -EOPNOTSUPP;
  }
  
  static inline int
  ext2_xattr_set(struct inode *inode, int name_index, const char *name,
  	       const void *value, size_t size, int flags)
  {
  	return -EOPNOTSUPP;
  }
  
  static inline void
  ext2_xattr_delete_inode(struct inode *inode)
  {
  }

  static inline void ext2_xattr_destroy_cache(struct mb_cache *cache)

  {
  }
  
  #define ext2_xattr_handlers NULL
  
  # endif  /* CONFIG_EXT2_FS_XATTR */

  #ifdef CONFIG_EXT2_FS_SECURITY

  extern int ext2_init_security(struct inode *inode, struct inode *dir,
  			      const struct qstr *qstr);

  #else

  static inline int ext2_init_security(struct inode *inode, struct inode *dir,
  				     const struct qstr *qstr)

  {
  	return 0;
  }
  #endif