Root/fs/ext4/xattr.h

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
25struct 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
33struct ext4_xattr_ibody_header {
34    __le32 h_magic; /* magic number for identification */
35};
36
37struct 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
68extern struct xattr_handler ext4_xattr_user_handler;
69extern struct xattr_handler ext4_xattr_trusted_handler;
70extern struct xattr_handler ext4_xattr_acl_access_handler;
71extern struct xattr_handler ext4_xattr_acl_default_handler;
72extern struct xattr_handler ext4_xattr_security_handler;
73
74extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
75
76extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
77extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
78extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
79
80extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
81extern void ext4_xattr_put_super(struct super_block *);
82
83extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
84                struct ext4_inode *raw_inode, handle_t *handle);
85
86extern int init_ext4_xattr(void);
87extern void exit_ext4_xattr(void);
88
89extern struct xattr_handler *ext4_xattr_handlers[];
90
91# else /* CONFIG_EXT4_FS_XATTR */
92
93static inline int
94ext4_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
100static inline int
101ext4_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
107static inline int
108ext4_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
114static inline void
115ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
116{
117}
118
119static inline void
120ext4_xattr_put_super(struct super_block *sb)
121{
122}
123
124static inline int
125init_ext4_xattr(void)
126{
127    return 0;
128}
129
130static inline void
131exit_ext4_xattr(void)
132{
133}
134
135static inline int
136ext4_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
147extern int ext4_init_security(handle_t *handle, struct inode *inode,
148                struct inode *dir);
149#else
150static inline int ext4_init_security(handle_t *handle, struct inode *inode,
151                struct inode *dir)
152{
153    return 0;
154}
155#endif
156

Archive Download this file



interactive