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gerrit.nordix.org / codeaurora / busybox / 1fd98e039d146dcff02a5350f509cabca65fd29c / . / e2fsprogs / ext2fs / ext2_ext_attr.h
blob: 23444c508137fe0090448554982bf8fbb68ef78b [file] [log] [blame]
Mike Frysinger1fd98e02005-05-09 22:10:42 +0000[diff] [blame^]1/*
2 File: linux/ext2_ext_attr.h
3
4 On-disk format of extended attributes for the ext2 filesystem.
5
6 (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7*/
8
9/* Magic value in attribute blocks */
10#define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000
11#define EXT2_EXT_ATTR_MAGIC 0xEA020000
12
13/* Maximum number of references to one attribute block */
14#define EXT2_EXT_ATTR_REFCOUNT_MAX 1024
15
16struct 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 */
22};
23
24struct 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 */
31#if 0
32 char e_name[0]; /* attribute name */
33#endif
34};
35
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)
55
56#ifdef __KERNEL__
57# ifdef CONFIG_EXT2_FS_EXT_ATTR
58extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int);
59extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int);
60extern void ext2_ext_attr_free_inode(struct inode *inode);
61extern void ext2_ext_attr_put_super(struct super_block *sb);
62extern int ext2_ext_attr_init(void);
63extern void ext2_ext_attr_done(void);
64# else
65# define ext2_get_ext_attr NULL
66# define ext2_set_ext_attr NULL
67# endif
68#endif /* __KERNEL__ */
69