2 File: linux/ext2_ext_attr.h
4 On-disk format of extended attributes for the ext2 filesystem.
6 (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org>
9 #ifndef _EXT2_EXT_ATTR_H
10 #define _EXT2_EXT_ATTR_H
11 /* Magic value in attribute blocks */
12 #define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000
13 #define EXT2_EXT_ATTR_MAGIC 0xEA020000
15 /* Maximum number of references to one attribute block */
16 #define EXT2_EXT_ATTR_REFCOUNT_MAX 1024
18 struct ext2_ext_attr_header {
19 __u32 h_magic; /* magic number for identification */
20 __u32 h_refcount; /* reference count */
21 __u32 h_blocks; /* number of disk blocks used */
22 __u32 h_hash; /* hash value of all attributes */
23 __u32 h_reserved[4]; /* zero right now */
26 struct ext2_ext_attr_entry {
27 __u8 e_name_len; /* length of name */
28 __u8 e_name_index; /* attribute name index */
29 __u16 e_value_offs; /* offset in disk block of value */
30 __u32 e_value_block; /* disk block attribute is stored on (n/i) */
31 __u32 e_value_size; /* size of attribute value */
32 __u32 e_hash; /* hash value of name and value */
34 char e_name[0]; /* attribute name */
38 #define EXT2_EXT_ATTR_PAD_BITS 2
39 #define EXT2_EXT_ATTR_PAD (1<<EXT2_EXT_ATTR_PAD_BITS)
40 #define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1)
41 #define EXT2_EXT_ATTR_LEN(name_len) \
42 (((name_len) + EXT2_EXT_ATTR_ROUND + \
43 sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND)
44 #define EXT2_EXT_ATTR_NEXT(entry) \
45 ( (struct ext2_ext_attr_entry *)( \
46 (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) )
47 #define EXT2_EXT_ATTR_SIZE(size) \
48 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
49 #define EXT2_EXT_IS_LAST_ENTRY(entry) (*((__u32 *)(entry)) == 0UL)
50 #define EXT2_EXT_ATTR_NAME(entry) \
51 (((char *) (entry)) + sizeof(struct ext2_ext_attr_entry))
52 #define EXT2_XATTR_LEN(name_len) \
53 (((name_len) + EXT2_EXT_ATTR_ROUND + \
54 sizeof(struct ext2_xattr_entry)) & ~EXT2_EXT_ATTR_ROUND)
55 #define EXT2_XATTR_SIZE(size) \
56 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
59 # ifdef CONFIG_EXT2_FS_EXT_ATTR
60 extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int);
61 extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int);
62 extern void ext2_ext_attr_free_inode(struct inode *inode);
63 extern void ext2_ext_attr_put_super(struct super_block *sb);
64 extern int ext2_ext_attr_init(void);
65 extern void ext2_ext_attr_done(void);
67 # define ext2_get_ext_attr NULL
68 # define ext2_set_ext_attr NULL
70 #endif /* __KERNEL__ */
71 #endif /* _EXT2_EXT_ATTR_H */