4 On-disk format of extended attributes for the ext4 filesystem.
6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
9 #include <linux/xattr.h>
11 /* Magic value in attribute blocks */
12 #define EXT4_XATTR_MAGIC 0xEA020000
14 /* Maximum number of references to one attribute block */
15 #define EXT4_XATTR_REFCOUNT_MAX 1024
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 #define EXT4_XATTR_INDEX_SYSTEM 7
26 struct ext4_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 __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
32 /* id = inum if refcount=1, blknum otherwise */
33 __u32 h_reserved[3]; /* zero right now */
36 struct ext4_xattr_ibody_header {
37 __le32 h_magic; /* magic number for identification */
40 struct ext4_xattr_entry {
41 __u8 e_name_len; /* length of name */
42 __u8 e_name_index; /* attribute name index */
43 __le16 e_value_offs; /* offset in disk block of value */
44 __le32 e_value_block; /* disk block attribute is stored on (n/i) */
45 __le32 e_value_size; /* size of attribute value */
46 __le32 e_hash; /* hash value of name and value */
47 char e_name[0]; /* attribute name */
50 #define EXT4_XATTR_PAD_BITS 2
51 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
52 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
53 #define EXT4_XATTR_LEN(name_len) \
54 (((name_len) + EXT4_XATTR_ROUND + \
55 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
56 #define EXT4_XATTR_NEXT(entry) \
57 ((struct ext4_xattr_entry *)( \
58 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
59 #define EXT4_XATTR_SIZE(size) \
60 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
62 #define IHDR(inode, raw_inode) \
63 ((struct ext4_xattr_ibody_header *) \
64 ((void *)raw_inode + \
65 EXT4_GOOD_OLD_INODE_SIZE + \
66 EXT4_I(inode)->i_extra_isize))
67 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
69 #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
70 #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
71 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
72 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
75 struct ext4_xattr_info {
82 struct ext4_xattr_search {
83 struct ext4_xattr_entry *first;
86 struct ext4_xattr_entry *here;
90 struct ext4_xattr_ibody_find {
91 struct ext4_xattr_search s;
92 struct ext4_iloc iloc;
95 # ifdef CONFIG_EXT4_FS_XATTR
97 extern const struct xattr_handler ext4_xattr_user_handler;
98 extern const struct xattr_handler ext4_xattr_trusted_handler;
99 extern const struct xattr_handler ext4_xattr_acl_access_handler;
100 extern const struct xattr_handler ext4_xattr_acl_default_handler;
101 extern const struct xattr_handler ext4_xattr_security_handler;
103 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
105 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
106 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
107 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
109 extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
110 extern void ext4_xattr_put_super(struct super_block *);
112 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
113 struct ext4_inode *raw_inode, handle_t *handle);
115 extern int __init ext4_init_xattr(void);
116 extern void ext4_exit_xattr(void);
118 extern const struct xattr_handler *ext4_xattr_handlers[];
120 extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
121 struct ext4_xattr_ibody_find *is);
122 extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
124 void *buffer, size_t buffer_size);
125 extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
126 struct ext4_xattr_info *i,
127 struct ext4_xattr_ibody_find *is);
129 extern int ext4_has_inline_data(struct inode *inode);
130 extern int ext4_get_inline_size(struct inode *inode);
131 extern int ext4_get_max_inline_size(struct inode *inode);
132 extern int ext4_find_inline_data_nolock(struct inode *inode);
133 extern void ext4_write_inline_data(struct inode *inode,
134 struct ext4_iloc *iloc,
135 void *buffer, loff_t pos,
137 extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
139 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
141 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
143 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
144 # else /* CONFIG_EXT4_FS_XATTR */
147 ext4_xattr_get(struct inode *inode, int name_index, const char *name,
148 void *buffer, size_t size, int flags)
154 ext4_xattr_set(struct inode *inode, int name_index, const char *name,
155 const void *value, size_t size, int flags)
161 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
162 const char *name, const void *value, size_t size, int flags)
168 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
173 ext4_xattr_put_super(struct super_block *sb)
177 static __init inline int
178 ext4_init_xattr(void)
184 ext4_exit_xattr(void)
189 ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
190 struct ext4_inode *raw_inode, handle_t *handle)
195 #define ext4_xattr_handlers NULL
198 ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
199 struct ext4_xattr_ibody_find *is)
205 ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
206 struct ext4_xattr_info *i,
207 struct ext4_xattr_ibody_find *is)
213 ext4_xattr_ibody_get(struct inode *inode, int name_index,
215 void *buffer, size_t buffer_size)
220 static inline int ext4_find_inline_data_nolock(struct inode *inode)
225 static inline int ext4_has_inline_data(struct inode *inode)
230 static inline int ext4_get_inline_size(struct inode *inode)
235 static inline int ext4_get_max_inline_size(struct inode *inode)
240 static inline void ext4_write_inline_data(struct inode *inode,
241 struct ext4_iloc *iloc,
242 void *buffer, loff_t pos,
248 static inline int ext4_init_inline_data(handle_t *handle,
255 static inline int ext4_destroy_inline_data(handle_t *handle,
261 static inline int ext4_readpage_inline(struct inode *inode, struct page *page)
265 # endif /* CONFIG_EXT4_FS_XATTR */
267 #ifdef CONFIG_EXT4_FS_SECURITY
268 extern int ext4_init_security(handle_t *handle, struct inode *inode,
269 struct inode *dir, const struct qstr *qstr);
271 static inline int ext4_init_security(handle_t *handle, struct inode *inode,
272 struct inode *dir, const struct qstr *qstr)