4 On-disk format of extended attributes for the ext3 filesystem.
6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
9 #include <linux/config.h>
10 #include <linux/xattr.h>
12 /* Magic value in attribute blocks */
13 #define EXT3_XATTR_MAGIC 0xEA020000
15 /* Maximum number of references to one attribute block */
16 #define EXT3_XATTR_REFCOUNT_MAX 1024
19 #define EXT3_XATTR_INDEX_MAX 10
20 #define EXT3_XATTR_INDEX_USER 1
21 #define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS 2
22 #define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT 3
23 #define EXT3_XATTR_INDEX_TRUSTED 4
24 #define EXT3_XATTR_INDEX_LUSTRE 5
25 #define EXT3_XATTR_INDEX_SECURITY 6
27 struct ext3_xattr_header {
28 __le32 h_magic; /* magic number for identification */
29 __le32 h_refcount; /* reference count */
30 __le32 h_blocks; /* number of disk blocks used */
31 __le32 h_hash; /* hash value of all attributes */
32 __u32 h_reserved[4]; /* zero right now */
35 struct ext3_xattr_entry {
36 __u8 e_name_len; /* length of name */
37 __u8 e_name_index; /* attribute name index */
38 __le16 e_value_offs; /* offset in disk block of value */
39 __le32 e_value_block; /* disk block attribute is stored on (n/i) */
40 __le32 e_value_size; /* size of attribute value */
41 __le32 e_hash; /* hash value of name and value */
42 char e_name[0]; /* attribute name */
45 #define EXT3_XATTR_PAD_BITS 2
46 #define EXT3_XATTR_PAD (1<<EXT3_XATTR_PAD_BITS)
47 #define EXT3_XATTR_ROUND (EXT3_XATTR_PAD-1)
48 #define EXT3_XATTR_LEN(name_len) \
49 (((name_len) + EXT3_XATTR_ROUND + \
50 sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
51 #define EXT3_XATTR_NEXT(entry) \
52 ( (struct ext3_xattr_entry *)( \
53 (char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
54 #define EXT3_XATTR_SIZE(size) \
55 (((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
57 # ifdef CONFIG_EXT3_FS_XATTR
59 struct ext3_xattr_handler {
61 size_t (*list)(char *list, struct inode *inode, const char *name,
63 int (*get)(struct inode *inode, const char *name, void *buffer,
65 int (*set)(struct inode *inode, const char *name, const void *buffer,
66 size_t size, int flags);
69 extern int ext3_xattr_register(int, struct ext3_xattr_handler *);
70 extern void ext3_xattr_unregister(int, struct ext3_xattr_handler *);
72 extern int ext3_setxattr(struct dentry *, const char *, const void *, size_t, int);
73 extern ssize_t ext3_getxattr(struct dentry *, const char *, void *, size_t);
74 extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
75 extern int ext3_removexattr(struct dentry *, const char *);
77 extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
78 extern int ext3_xattr_list(struct inode *, char *, size_t);
79 extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
80 extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
82 extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
83 extern void ext3_xattr_put_super(struct super_block *);
85 extern int init_ext3_xattr(void);
86 extern void exit_ext3_xattr(void);
88 # else /* CONFIG_EXT3_FS_XATTR */
89 # define ext3_setxattr NULL
90 # define ext3_getxattr NULL
91 # define ext3_listxattr NULL
92 # define ext3_removexattr NULL
95 ext3_xattr_get(struct inode *inode, int name_index, const char *name,
96 void *buffer, size_t size, int flags)
102 ext3_xattr_list(struct inode *inode, void *buffer, size_t size)
108 ext3_xattr_set(struct inode *inode, int name_index, const char *name,
109 const void *value, size_t size, int flags)
115 ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
116 const char *name, const void *value, size_t size, int flags)
122 ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
127 ext3_xattr_put_super(struct super_block *sb)
132 init_ext3_xattr(void)
138 exit_ext3_xattr(void)
142 # endif /* CONFIG_EXT3_FS_XATTR */
144 extern struct ext3_xattr_handler ext3_xattr_user_handler;
145 extern struct ext3_xattr_handler ext3_xattr_trusted_handler;
146 extern struct ext3_xattr_handler ext3_xattr_security_handler;