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 /* Magic value in attribute blocks */
10 #define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000
11 #define EXT2_EXT_ATTR_MAGIC 0xEA020000
13 /* Maximum number of references to one attribute block */
14 #define EXT2_EXT_ATTR_REFCOUNT_MAX 1024
16 struct ext2_ext_attr_header {
17 __u32 h_magic; /* magic number for identification */
18 __u32 h_refcount; /* reference count */
19 __u32 h_blocks; /* number of disk blocks used */
20 __u32 h_hash; /* hash value of all attributes */
21 __u32 h_reserved[4]; /* zero right now */
24 struct ext2_ext_attr_entry {
25 __u8 e_name_len; /* length of name */
26 __u8 e_name_index; /* attribute name index */
27 __u16 e_value_offs; /* offset in disk block of value */
28 __u32 e_value_block; /* disk block attribute is stored on (n/i) */
29 __u32 e_value_size; /* size of attribute value */
30 __u32 e_hash; /* hash value of name and value */
32 char e_name[0]; /* attribute name */
36 #define EXT2_EXT_ATTR_PAD_BITS 2
37 #define EXT2_EXT_ATTR_PAD (1<<EXT2_EXT_ATTR_PAD_BITS)
38 #define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1)
39 #define EXT2_EXT_ATTR_LEN(name_len) \
40 (((name_len) + EXT2_EXT_ATTR_ROUND + \
41 sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND)
42 #define EXT2_EXT_ATTR_NEXT(entry) \
43 ( (struct ext2_ext_attr_entry *)( \
44 (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) )
45 #define EXT2_EXT_ATTR_SIZE(size) \
46 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
47 #define EXT2_EXT_IS_LAST_ENTRY(entry) (*((__u32 *)(entry)) == 0UL)
48 #define EXT2_EXT_ATTR_NAME(entry) \
49 (((char *) (entry)) + sizeof(struct ext2_ext_attr_entry))
50 #define EXT2_XATTR_LEN(name_len) \
51 (((name_len) + EXT2_EXT_ATTR_ROUND + \
52 sizeof(struct ext2_xattr_entry)) & ~EXT2_EXT_ATTR_ROUND)
53 #define EXT2_XATTR_SIZE(size) \
54 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND)
57 # ifdef CONFIG_EXT2_FS_EXT_ATTR
58 extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int);
59 extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int);
60 extern void ext2_ext_attr_free_inode(struct inode *inode);
61 extern void ext2_ext_attr_put_super(struct super_block *sb);
62 extern int ext2_ext_attr_init(void);
63 extern void ext2_ext_attr_done(void);
65 # define ext2_get_ext_attr NULL
66 # define ext2_set_ext_attr NULL
68 #endif /* __KERNEL__ */