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
25 struct 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
33 struct ext3_xattr_ibody_header {
34 __le32 h_magic; /* magic number for identification */
35 };
36
37 struct 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
61 extern const struct xattr_handler ext3_xattr_user_handler;
62 extern const struct xattr_handler ext3_xattr_trusted_handler;
63 extern const struct xattr_handler ext3_xattr_security_handler;
64
65 extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
66
67 extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
68 extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
69 extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
70
71 extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
72 extern void ext3_xattr_put_super(struct super_block *);
73
74 extern int init_ext3_xattr(void);
75 extern void exit_ext3_xattr(void);
76
77 extern const struct xattr_handler *ext3_xattr_handlers[];
78
79 # else /* CONFIG_EXT3_FS_XATTR */
80
81 static inline int
ext3_xattr_get(struct inode * inode,int name_index,const char * name,void * buffer,size_t size,int flags)82 ext3_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
88 static inline int
ext3_xattr_set(struct inode * inode,int name_index,const char * name,const void * value,size_t size,int flags)89 ext3_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
95 static inline int
ext3_xattr_set_handle(handle_t * handle,struct inode * inode,int name_index,const char * name,const void * value,size_t size,int flags)96 ext3_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
102 static inline void
ext3_xattr_delete_inode(handle_t * handle,struct inode * inode)103 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
104 {
105 }
106
107 static inline void
ext3_xattr_put_super(struct super_block * sb)108 ext3_xattr_put_super(struct super_block *sb)
109 {
110 }
111
112 static inline int
init_ext3_xattr(void)113 init_ext3_xattr(void)
114 {
115 return 0;
116 }
117
118 static inline void
exit_ext3_xattr(void)119 exit_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
128 extern int ext3_init_security(handle_t *handle, struct inode *inode,
129 struct inode *dir, const struct qstr *qstr);
130 #else
ext3_init_security(handle_t * handle,struct inode * inode,struct inode * dir,const struct qstr * qstr)131 static 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
137