Line data Source code
1 : /*
2 : File: linux/ext2_xattr.h
3 :
4 : On-disk format of extended attributes for the ext2 filesystem.
5 :
6 : (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7 : */
8 :
9 : #include <linux/init.h>
10 : #include <linux/xattr.h>
11 :
12 : /* Magic value in attribute blocks */
13 : #define EXT2_XATTR_MAGIC 0xEA020000
14 :
15 : /* Maximum number of references to one attribute block */
16 : #define EXT2_XATTR_REFCOUNT_MAX 1024
17 :
18 : /* Name indexes */
19 : #define EXT2_XATTR_INDEX_USER 1
20 : #define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2
21 : #define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3
22 : #define EXT2_XATTR_INDEX_TRUSTED 4
23 : #define EXT2_XATTR_INDEX_LUSTRE 5
24 : #define EXT2_XATTR_INDEX_SECURITY 6
25 :
26 : struct ext2_xattr_header {
27 : __le32 h_magic; /* magic number for identification */
28 : __le32 h_refcount; /* reference count */
29 : __le32 h_blocks; /* number of disk blocks used */
30 : __le32 h_hash; /* hash value of all attributes */
31 : __u32 h_reserved[4]; /* zero right now */
32 : };
33 1 :
34 : struct ext2_xattr_entry {
35 : __u8 e_name_len; /* length of name */
36 : __u8 e_name_index; /* attribute name index */
37 : __le16 e_value_offs; /* offset in disk block of value */
38 : __le32 e_value_block; /* disk block attribute is stored on (n/i) */
39 : __le32 e_value_size; /* size of attribute value */
40 : __le32 e_hash; /* hash value of name and value */
41 : char e_name[0]; /* attribute name */
42 : };
43 :
44 : #define EXT2_XATTR_PAD_BITS 2
45 : #define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS)
46 : #define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1)
47 : #define EXT2_XATTR_LEN(name_len) \
48 : (((name_len) + EXT2_XATTR_ROUND + \
49 : sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
50 : #define EXT2_XATTR_NEXT(entry) \
51 : ( (struct ext2_xattr_entry *)( \
52 : (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
53 : #define EXT2_XATTR_SIZE(size) \
54 : (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
55 :
56 : # ifdef CONFIG_EXT2_FS_XATTR
57 :
58 1 : extern struct xattr_handler ext2_xattr_user_handler;
59 1 : extern struct xattr_handler ext2_xattr_trusted_handler;
60 : extern struct xattr_handler ext2_xattr_acl_access_handler;
61 : extern struct xattr_handler ext2_xattr_acl_default_handler;
62 1 : extern struct xattr_handler ext2_xattr_security_handler;
63 :
64 : extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
65 :
66 : extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
67 : extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
68 :
69 : extern void ext2_xattr_delete_inode(struct inode *);
70 : extern void ext2_xattr_put_super(struct super_block *);
71 :
72 : extern int init_ext2_xattr(void);
73 : extern void exit_ext2_xattr(void);
74 :
75 1 : extern struct xattr_handler *ext2_xattr_handlers[];
76 :
77 : # else /* CONFIG_EXT2_FS_XATTR */
78 :
79 : static inline int
80 : ext2_xattr_get(struct inode *inode, int name_index,
81 : const char *name, void *buffer, size_t size)
82 : {
83 : return -EOPNOTSUPP;
84 : }
85 :
86 : static inline int
87 : ext2_xattr_set(struct inode *inode, int name_index, const char *name,
88 : const void *value, size_t size, int flags)
89 : {
90 : return -EOPNOTSUPP;
91 : }
92 :
93 : static inline void
94 : ext2_xattr_delete_inode(struct inode *inode)
95 : {
96 : }
97 :
98 : static inline void
99 : ext2_xattr_put_super(struct super_block *sb)
100 : {
101 : }
102 :
103 : static inline int
104 : init_ext2_xattr(void)
105 : {
106 : return 0;
107 : }
108 :
109 : static inline void
110 : exit_ext2_xattr(void)
111 : {
112 : }
113 :
114 : #define ext2_xattr_handlers NULL
115 :
116 : # endif /* CONFIG_EXT2_FS_XATTR */
117 :
118 : #ifdef CONFIG_EXT2_FS_SECURITY
119 : extern int ext2_init_security(struct inode *inode, struct inode *dir);
120 : #else
121 : static inline int ext2_init_security(struct inode *inode, struct inode *dir)
122 : {
123 : return 0;
124 : }
125 : #endif
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