1 /*
2 File: fs/ext4/xattr.h
3
4 On-disk format of extended attributes for the ext4 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 EXT4_XATTR_MAGIC 0xEA020000
13
14 /* Maximum number of references to one attribute block */
15 #define EXT4_XATTR_REFCOUNT_MAX 1024
16
17 /* Name indexes */
18 #define EXT4_XATTR_INDEX_USER 1
19 #define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
20 #define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
21 #define EXT4_XATTR_INDEX_TRUSTED 4
22 #define EXT4_XATTR_INDEX_LUSTRE 5
23 #define EXT4_XATTR_INDEX_SECURITY 6
24
25 struct ext4_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 ext4_xattr_ibody_header {
34 __le32 h_magic; /* magic number for identification */
35 };
36
37 struct ext4_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 EXT4_XATTR_PAD_BITS 2
48 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
49 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
50 #define EXT4_XATTR_LEN(name_len) \
51 (((name_len) + EXT4_XATTR_ROUND + \
52 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
53 #define EXT4_XATTR_NEXT(entry) \
54 ((struct ext4_xattr_entry *)( \
55 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
56 #define EXT4_XATTR_SIZE(size) \
57 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
58
59 #define IHDR(inode, raw_inode) \
60 ((struct ext4_xattr_ibody_header *) \
61 ((void *)raw_inode + \
62 EXT4_GOOD_OLD_INODE_SIZE + \
63 EXT4_I(inode)->i_extra_isize))
64 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
65
66 # ifdef CONFIG_EXT4_FS_XATTR
67
68 extern struct xattr_handler ext4_xattr_user_handler;
69 extern struct xattr_handler ext4_xattr_trusted_handler;
70 extern struct xattr_handler ext4_xattr_acl_access_handler;
71 extern struct xattr_handler ext4_xattr_acl_default_handler;
72 extern struct xattr_handler ext4_xattr_security_handler;
73
74 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
75
76 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
77 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
78 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
79
80 extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
81 extern void ext4_xattr_put_super(struct super_block *);
82
83 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
84 struct ext4_inode *raw_inode, handle_t *handle);
85
86 extern int init_ext4_xattr(void);
87 extern void exit_ext4_xattr(void);
88
89 extern struct xattr_handler *ext4_xattr_handlers[];
90
91 # else /* CONFIG_EXT4_FS_XATTR */
92
93 static inline int
ext4_xattr_get(struct inode * inode,int name_index,const char * name,void * buffer,size_t size,int flags)94 ext4_xattr_get(struct inode *inode, int name_index, const char *name,
95 void *buffer, size_t size, int flags)
96 {
97 return -EOPNOTSUPP;
98 }
99
100 static inline int
ext4_xattr_set(struct inode * inode,int name_index,const char * name,const void * value,size_t size,int flags)101 ext4_xattr_set(struct inode *inode, int name_index, const char *name,
102 const void *value, size_t size, int flags)
103 {
104 return -EOPNOTSUPP;
105 }
106
107 static inline int
ext4_xattr_set_handle(handle_t * handle,struct inode * inode,int name_index,const char * name,const void * value,size_t size,int flags)108 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
109 const char *name, const void *value, size_t size, int flags)
110 {
111 return -EOPNOTSUPP;
112 }
113
114 static inline void
ext4_xattr_delete_inode(handle_t * handle,struct inode * inode)115 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
116 {
117 }
118
119 static inline void
ext4_xattr_put_super(struct super_block * sb)120 ext4_xattr_put_super(struct super_block *sb)
121 {
122 }
123
124 static inline int
init_ext4_xattr(void)125 init_ext4_xattr(void)
126 {
127 return 0;
128 }
129
130 static inline void
exit_ext4_xattr(void)131 exit_ext4_xattr(void)
132 {
133 }
134
135 static inline int
ext4_expand_extra_isize_ea(struct inode * inode,int new_extra_isize,struct ext4_inode * raw_inode,handle_t * handle)136 ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
137 struct ext4_inode *raw_inode, handle_t *handle)
138 {
139 return -EOPNOTSUPP;
140 }
141
142 #define ext4_xattr_handlers NULL
143
144 # endif /* CONFIG_EXT4_FS_XATTR */
145
146 #ifdef CONFIG_EXT4_FS_SECURITY
147 extern int ext4_init_security(handle_t *handle, struct inode *inode,
148 struct inode *dir);
149 #else
ext4_init_security(handle_t * handle,struct inode * inode,struct inode * dir)150 static inline int ext4_init_security(handle_t *handle, struct inode *inode,
151 struct inode *dir)
152 {
153 return 0;
154 }
155 #endif
156