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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 File: linux/ext2_xattr.h
4
5 On-disk format of extended attributes for the ext2 filesystem.
6
7 (C) 2001 Andreas Gruenbacher, <[email protected]>
8*/
9
10#include <linux/init.h>
11#include <linux/xattr.h>
12
13/* Magic value in attribute blocks */
14#define EXT2_XATTR_MAGIC 0xEA020000
15
16/* Maximum number of references to one attribute block */
17#define EXT2_XATTR_REFCOUNT_MAX 1024
18
19/* Name indexes */
20#define EXT2_XATTR_INDEX_USER 1
21#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2
22#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3
23#define EXT2_XATTR_INDEX_TRUSTED 4
24#define EXT2_XATTR_INDEX_LUSTRE 5
25#define EXT2_XATTR_INDEX_SECURITY 6
26
27struct ext2_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 */
33};
34
35struct ext2_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[]; /* attribute name */
43};
44
45#define EXT2_XATTR_PAD_BITS 2
46#define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS)
47#define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1)
48#define EXT2_XATTR_LEN(name_len) \
49 (((name_len) + EXT2_XATTR_ROUND + \
50 sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
51#define EXT2_XATTR_NEXT(entry) \
52 ( (struct ext2_xattr_entry *)( \
53 (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
54#define EXT2_XATTR_SIZE(size) \
55 (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
56
57struct mb_cache;
58
59# ifdef CONFIG_EXT2_FS_XATTR
60
61extern const struct xattr_handler ext2_xattr_user_handler;
62extern const struct xattr_handler ext2_xattr_trusted_handler;
63extern const struct xattr_handler ext2_xattr_security_handler;
64
65extern ssize_t ext2_listxattr(struct dentry *, char *, size_t);
66
67extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t);
68extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
69
70extern void ext2_xattr_delete_inode(struct inode *);
71
72extern struct mb_cache *ext2_xattr_create_cache(void);
73extern void ext2_xattr_destroy_cache(struct mb_cache *cache);
74
75extern const struct xattr_handler * const ext2_xattr_handlers[];
76
77# else /* CONFIG_EXT2_FS_XATTR */
78
79static inline int
80ext2_xattr_get(struct inode *inode, int name_index,
81 const char *name, void *buffer, size_t size)
82{
83 return -EOPNOTSUPP;
84}
85
86static inline int
87ext2_xattr_set(struct inode *inode, int name_index, const char *name,
88 const void *value, size_t size, int flags)
89{
90 return -EOPNOTSUPP;
91}
92
93static inline void
94ext2_xattr_delete_inode(struct inode *inode)
95{
96}
97
98static inline void ext2_xattr_destroy_cache(struct mb_cache *cache)
99{
100}
101
102#define ext2_xattr_handlers NULL
103#define ext2_listxattr NULL
104
105# endif /* CONFIG_EXT2_FS_XATTR */
106
107#ifdef CONFIG_EXT2_FS_SECURITY
108extern int ext2_init_security(struct inode *inode, struct inode *dir,
109 const struct qstr *qstr);
110#else
111static inline int ext2_init_security(struct inode *inode, struct inode *dir,
112 const struct qstr *qstr)
113{
114 return 0;
115}
116#endif