/*

    File: fs/ext4/xattr.h

    On-disk format of extended attributes for the ext4 filesystem.

  
    (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
  */
  
  #include <linux/xattr.h>
  
  /* Magic value in attribute blocks */

  #define EXT4_XATTR_MAGIC		0xEA020000

  
  /* Maximum number of references to one attribute block */

  #define EXT4_XATTR_REFCOUNT_MAX		1024

  
  /* Name indexes */

  #define EXT4_XATTR_INDEX_USER			1
  #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS	2
  #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT	3
  #define EXT4_XATTR_INDEX_TRUSTED		4
  #define	EXT4_XATTR_INDEX_LUSTRE			5
  #define EXT4_XATTR_INDEX_SECURITY	        6

  #define EXT4_XATTR_INDEX_SYSTEM			7

  #define EXT4_XATTR_INDEX_RICHACL		8

  #define EXT4_XATTR_INDEX_ENCRYPTION		9

  #define EXT4_XATTR_INDEX_HURD			10 /* Reserved for Hurd */

  
  struct ext4_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 */

  	__le32	h_checksum;	/* crc32c(uuid+id+xattrblock) */
  				/* id = inum if refcount=1, blknum otherwise */
  	__u32	h_reserved[3];	/* zero right now */

  };

  struct ext4_xattr_ibody_header {

  	__le32	h_magic;	/* magic number for identification */
  };

  struct ext4_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 EXT4_XATTR_PAD_BITS		2
  #define EXT4_XATTR_PAD		(1<<EXT4_XATTR_PAD_BITS)
  #define EXT4_XATTR_ROUND		(EXT4_XATTR_PAD-1)
  #define EXT4_XATTR_LEN(name_len) \
  	(((name_len) + EXT4_XATTR_ROUND + \
  	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
  #define EXT4_XATTR_NEXT(entry) \

  	((struct ext4_xattr_entry *)( \
  	 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))

  #define EXT4_XATTR_SIZE(size) \
  	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)

  #define IHDR(inode, raw_inode) \
  	((struct ext4_xattr_ibody_header *) \
  		((void *)raw_inode + \
  		EXT4_GOOD_OLD_INODE_SIZE + \
  		EXT4_I(inode)->i_extra_isize))
  #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))

  #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
  #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
  #define BFIRST(bh) ENTRY(BHDR(bh)+1)
  #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)

  #define EXT4_ZERO_XATTR_VALUE ((void *)-1)

  
  struct ext4_xattr_info {
  	int name_index;
  	const char *name;
  	const void *value;
  	size_t value_len;
  };
  
  struct ext4_xattr_search {
  	struct ext4_xattr_entry *first;
  	void *base;
  	void *end;
  	struct ext4_xattr_entry *here;
  	int not_found;
  };
  
  struct ext4_xattr_ibody_find {
  	struct ext4_xattr_search s;
  	struct ext4_iloc iloc;
  };

  extern const struct xattr_handler ext4_xattr_user_handler;
  extern const struct xattr_handler ext4_xattr_trusted_handler;

  extern const struct xattr_handler ext4_xattr_security_handler;

  #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"

  extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);

  extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);

  extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
  extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);

  extern void ext4_xattr_delete_inode(handle_t *, struct inode *);

  extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
  			    struct ext4_inode *raw_inode, handle_t *handle);

  extern const struct xattr_handler *ext4_xattr_handlers[];

  extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
  				 struct ext4_xattr_ibody_find *is);
  extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
  				const char *name,
  				void *buffer, size_t buffer_size);

  extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
  				       struct ext4_xattr_info *i,
  				       struct ext4_xattr_ibody_find *is);

  extern struct mb_cache *ext4_xattr_create_cache(void);
  extern void ext4_xattr_destroy_cache(struct mb_cache *);

  #ifdef CONFIG_EXT4_FS_SECURITY

  extern int ext4_init_security(handle_t *handle, struct inode *inode,

  			      struct inode *dir, const struct qstr *qstr);

  #else

  static inline int ext4_init_security(handle_t *handle, struct inode *inode,

  				     struct inode *dir, const struct qstr *qstr)

  {
  	return 0;
  }
  #endif