1/*
  2  File: fs/ext3/xattr.h
  3
  4  On-disk format of extended attributes for the ext3 filesystem.
  5
  6  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
  7*/
  8
  9#include <linux/xattr.h>
 10
 11/* Magic value in attribute blocks */
 12#define EXT3_XATTR_MAGIC		0xEA020000
 13
 14/* Maximum number of references to one attribute block */
 15#define EXT3_XATTR_REFCOUNT_MAX		1024
 16
 17/* Name indexes */
 18#define EXT3_XATTR_INDEX_USER			1
 19#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS	2
 20#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT	3
 21#define EXT3_XATTR_INDEX_TRUSTED		4
 22#define	EXT3_XATTR_INDEX_LUSTRE			5
 23#define EXT3_XATTR_INDEX_SECURITY	        6
 24
 25struct ext3_xattr_header {
 26	__le32	h_magic;	/* magic number for identification */
 27	__le32	h_refcount;	/* reference count */
 28	__le32	h_blocks;	/* number of disk blocks used */
 29	__le32	h_hash;		/* hash value of all attributes */
 30	__u32	h_reserved[4];	/* zero right now */
 31};
 32
 33struct ext3_xattr_ibody_header {
 34	__le32	h_magic;	/* magic number for identification */
 35};
 36
 37struct ext3_xattr_entry {
 38	__u8	e_name_len;	/* length of name */
 39	__u8	e_name_index;	/* attribute name index */
 40	__le16	e_value_offs;	/* offset in disk block of value */
 41	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
 42	__le32	e_value_size;	/* size of attribute value */
 43	__le32	e_hash;		/* hash value of name and value */
 44	char	e_name[0];	/* attribute name */
 45};
 46
 47#define EXT3_XATTR_PAD_BITS		2
 48#define EXT3_XATTR_PAD		(1<<EXT3_XATTR_PAD_BITS)
 49#define EXT3_XATTR_ROUND		(EXT3_XATTR_PAD-1)
 50#define EXT3_XATTR_LEN(name_len) \
 51	(((name_len) + EXT3_XATTR_ROUND + \
 52	sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
 53#define EXT3_XATTR_NEXT(entry) \
 54	( (struct ext3_xattr_entry *)( \
 55	  (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
 56#define EXT3_XATTR_SIZE(size) \
 57	(((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
 58
 59# ifdef CONFIG_EXT3_FS_XATTR
 60
 61extern const struct xattr_handler ext3_xattr_user_handler;
 62extern const struct xattr_handler ext3_xattr_trusted_handler;
 63extern const struct xattr_handler ext3_xattr_security_handler;
 64
 65extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
 66
 67extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
 68extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
 69extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
 70
 71extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
 72extern void ext3_xattr_put_super(struct super_block *);
 73
 74extern int init_ext3_xattr(void);
 75extern void exit_ext3_xattr(void);
 76
 77extern const struct xattr_handler *ext3_xattr_handlers[];
 78
 79# else  /* CONFIG_EXT3_FS_XATTR */
 80
 81static inline int
 82ext3_xattr_get(struct inode *inode, int name_index, const char *name,
 83	       void *buffer, size_t size, int flags)
 84{
 85	return -EOPNOTSUPP;
 86}
 87
 88static inline int
 89ext3_xattr_set(struct inode *inode, int name_index, const char *name,
 90	       const void *value, size_t size, int flags)
 91{
 92	return -EOPNOTSUPP;
 93}
 94
 95static inline int
 96ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
 97	       const char *name, const void *value, size_t size, int flags)
 98{
 99	return -EOPNOTSUPP;
100}
101
102static inline void
103ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
104{
105}
106
107static inline void
108ext3_xattr_put_super(struct super_block *sb)
109{
110}
111
112static inline int
113init_ext3_xattr(void)
114{
115	return 0;
116}
117
118static inline void
119exit_ext3_xattr(void)
120{
121}
122
123#define ext3_xattr_handlers	NULL
124
125# endif  /* CONFIG_EXT3_FS_XATTR */
126
127#ifdef CONFIG_EXT3_FS_SECURITY
128extern int ext3_init_security(handle_t *handle, struct inode *inode,
129			      struct inode *dir, const struct qstr *qstr);
130#else
131static inline int ext3_init_security(handle_t *handle, struct inode *inode,
132				     struct inode *dir, const struct qstr *qstr)
133{
134	return 0;
135}
136#endif