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Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 File: fs/ext4/xattr.h
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003
Mingming Cao617ba132006-10-11 01:20:53 -07004 On-disk format of extended attributes for the ext4 filesystem.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005
6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7*/
8
9#include <linux/xattr.h>
10
11/* Magic value in attribute blocks */
Mingming Cao617ba132006-10-11 01:20:53 -070012#define EXT4_XATTR_MAGIC 0xEA020000
Dave Kleikampac27a0e2006-10-11 01:20:50 -070013
14/* Maximum number of references to one attribute block */
Mingming Cao617ba132006-10-11 01:20:53 -070015#define EXT4_XATTR_REFCOUNT_MAX 1024
Dave Kleikampac27a0e2006-10-11 01:20:50 -070016
17/* Name indexes */
Mingming Cao617ba132006-10-11 01:20:53 -070018#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
Dave Kleikampac27a0e2006-10-11 01:20:50 -070024
Mingming Cao617ba132006-10-11 01:20:53 -070025struct ext4_xattr_header {
Dave Kleikampac27a0e2006-10-11 01:20:50 -070026 __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
Mingming Cao617ba132006-10-11 01:20:53 -070033struct ext4_xattr_ibody_header {
Dave Kleikampac27a0e2006-10-11 01:20:50 -070034 __le32 h_magic; /* magic number for identification */
35};
36
Mingming Cao617ba132006-10-11 01:20:53 -070037struct ext4_xattr_entry {
Dave Kleikampac27a0e2006-10-11 01:20:50 -070038 __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
Mingming Cao617ba132006-10-11 01:20:53 -070047#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)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070058
Kalpak Shah6dd4ee72007-07-18 09:19:57 -040059#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
Mingming Cao617ba132006-10-11 01:20:53 -070066# ifdef CONFIG_EXT4DEV_FS_XATTR
Dave Kleikampac27a0e2006-10-11 01:20:50 -070067
Mingming Cao617ba132006-10-11 01:20:53 -070068extern 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;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070073
Mingming Cao617ba132006-10-11 01:20:53 -070074extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070075
Mingming Cao617ba132006-10-11 01:20:53 -070076extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
Mingming Cao617ba132006-10-11 01:20:53 -070077extern 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);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070079
Mingming Cao617ba132006-10-11 01:20:53 -070080extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
81extern void ext4_xattr_put_super(struct super_block *);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070082
Kalpak Shah6dd4ee72007-07-18 09:19:57 -040083extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
84 struct ext4_inode *raw_inode, handle_t *handle);
85
Mingming Cao617ba132006-10-11 01:20:53 -070086extern int init_ext4_xattr(void);
87extern void exit_ext4_xattr(void);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070088
Mingming Cao617ba132006-10-11 01:20:53 -070089extern struct xattr_handler *ext4_xattr_handlers[];
Dave Kleikampac27a0e2006-10-11 01:20:50 -070090
Mingming Cao617ba132006-10-11 01:20:53 -070091# else /* CONFIG_EXT4DEV_FS_XATTR */
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092
93static inline int
Mingming Cao617ba132006-10-11 01:20:53 -070094ext4_xattr_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095 void *buffer, size_t size, int flags)
96{
97 return -EOPNOTSUPP;
98}
99
100static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700101ext4_xattr_set(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700102 const void *value, size_t size, int flags)
103{
104 return -EOPNOTSUPP;
105}
106
107static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700108ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700109 const char *name, const void *value, size_t size, int flags)
110{
111 return -EOPNOTSUPP;
112}
113
114static inline void
Mingming Cao617ba132006-10-11 01:20:53 -0700115ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116{
117}
118
119static inline void
Mingming Cao617ba132006-10-11 01:20:53 -0700120ext4_xattr_put_super(struct super_block *sb)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700121{
122}
123
124static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700125init_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700126{
127 return 0;
128}
129
130static inline void
Mingming Cao617ba132006-10-11 01:20:53 -0700131exit_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700132{
133}
134
Kalpak Shah6dd4ee72007-07-18 09:19:57 -0400135static 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
Mingming Cao617ba132006-10-11 01:20:53 -0700142#define ext4_xattr_handlers NULL
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700143
Mingming Cao617ba132006-10-11 01:20:53 -0700144# endif /* CONFIG_EXT4DEV_FS_XATTR */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700145
Mingming Cao617ba132006-10-11 01:20:53 -0700146#ifdef CONFIG_EXT4DEV_FS_SECURITY
147extern int ext4_init_security(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700148 struct inode *dir);
149#else
Mingming Cao617ba132006-10-11 01:20:53 -0700150static inline int ext4_init_security(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700151 struct inode *dir)
152{
153 return 0;
154}
155#endif