1 /*
2 * fs/f2fs/xattr.h
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * Portions of this code from linux/fs/ext2/xattr.h
8 *
9 * On-disk format of extended attributes for the ext2 filesystem.
10 *
11 * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
16 */
17 #ifndef __F2FS_XATTR_H__
18 #define __F2FS_XATTR_H__
19
20 #include <linux/init.h>
21 #include <linux/xattr.h>
22
23 /* Magic value in attribute blocks */
24 #define F2FS_XATTR_MAGIC 0xF2F52011
25
26 /* Maximum number of references to one attribute block */
27 #define F2FS_XATTR_REFCOUNT_MAX 1024
28
29 /* Name indexes */
30 #define F2FS_SYSTEM_ADVISE_NAME "system.advise"
31 #define F2FS_XATTR_INDEX_USER 1
32 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS 2
33 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT 3
34 #define F2FS_XATTR_INDEX_TRUSTED 4
35 #define F2FS_XATTR_INDEX_LUSTRE 5
36 #define F2FS_XATTR_INDEX_SECURITY 6
37 #define F2FS_XATTR_INDEX_ADVISE 7
38 /* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
39 #define F2FS_XATTR_INDEX_ENCRYPTION 9
40
41 #define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT "c"
42
43 struct f2fs_xattr_header {
44 __le32 h_magic; /* magic number for identification */
45 __le32 h_refcount; /* reference count */
46 __u32 h_reserved[4]; /* zero right now */
47 };
48
49 struct f2fs_xattr_entry {
50 __u8 e_name_index;
51 __u8 e_name_len;
52 __le16 e_value_size; /* size of attribute value */
53 char e_name[0]; /* attribute name */
54 };
55
56 #define XATTR_HDR(ptr) ((struct f2fs_xattr_header *)(ptr))
57 #define XATTR_ENTRY(ptr) ((struct f2fs_xattr_entry *)(ptr))
58 #define XATTR_FIRST_ENTRY(ptr) (XATTR_ENTRY(XATTR_HDR(ptr) + 1))
59 #define XATTR_ROUND (3)
60
61 #define XATTR_ALIGN(size) (((size) + XATTR_ROUND) & ~XATTR_ROUND)
62
63 #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
64 (entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
65
66 #define XATTR_NEXT_ENTRY(entry) ((struct f2fs_xattr_entry *)((char *)(entry) +\
67 ENTRY_SIZE(entry)))
68
69 #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
70
71 #define list_for_each_xattr(entry, addr) \
72 for (entry = XATTR_FIRST_ENTRY(addr);\
73 !IS_XATTR_LAST_ENTRY(entry);\
74 entry = XATTR_NEXT_ENTRY(entry))
75 #define VALID_XATTR_BLOCK_SIZE (PAGE_SIZE - sizeof(struct node_footer))
76 #define XATTR_PADDING_SIZE (sizeof(__u32))
77 #define XATTR_SIZE(x,i) (((x) ? VALID_XATTR_BLOCK_SIZE : 0) + \
78 (inline_xattr_size(i)))
79 #define MIN_OFFSET(i) XATTR_ALIGN(inline_xattr_size(i) + \
80 VALID_XATTR_BLOCK_SIZE)
81
82 #define MAX_VALUE_LEN(i) (MIN_OFFSET(i) - \
83 sizeof(struct f2fs_xattr_header) - \
84 sizeof(struct f2fs_xattr_entry))
85
86 /*
87 * On-disk structure of f2fs_xattr
88 * We use inline xattrs space + 1 block for xattr.
89 *
90 * +--------------------+
91 * | f2fs_xattr_header |
92 * | |
93 * +--------------------+
94 * | f2fs_xattr_entry |
95 * | .e_name_index = 1 |
96 * | .e_name_len = 3 |
97 * | .e_value_size = 14 |
98 * | .e_name = "foo" |
99 * | "value_of_xattr" |<- value_offs = e_name + e_name_len
100 * +--------------------+
101 * | f2fs_xattr_entry |
102 * | .e_name_index = 4 |
103 * | .e_name = "bar" |
104 * +--------------------+
105 * | |
106 * | Free |
107 * | |
108 * +--------------------+<- MIN_OFFSET
109 * | node_footer |
110 * | (nid, ino, offset) |
111 * +--------------------+
112 *
113 **/
114
115 #ifdef CONFIG_F2FS_FS_XATTR
116 extern const struct xattr_handler f2fs_xattr_user_handler;
117 extern const struct xattr_handler f2fs_xattr_trusted_handler;
118 extern const struct xattr_handler f2fs_xattr_advise_handler;
119 extern const struct xattr_handler f2fs_xattr_security_handler;
120
121 extern const struct xattr_handler *f2fs_xattr_handlers[];
122
123 extern int f2fs_setxattr(struct inode *, int, const char *,
124 const void *, size_t, struct page *, int);
125 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
126 size_t, struct page *);
127 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
128 #else
129
130 #define f2fs_xattr_handlers NULL
f2fs_setxattr(struct inode * inode,int index,const char * name,const void * value,size_t size,struct page * page,int flags)131 static inline int f2fs_setxattr(struct inode *inode, int index,
132 const char *name, const void *value, size_t size,
133 struct page *page, int flags)
134 {
135 return -EOPNOTSUPP;
136 }
f2fs_getxattr(struct inode * inode,int index,const char * name,void * buffer,size_t buffer_size,struct page * dpage)137 static inline int f2fs_getxattr(struct inode *inode, int index,
138 const char *name, void *buffer,
139 size_t buffer_size, struct page *dpage)
140 {
141 return -EOPNOTSUPP;
142 }
f2fs_listxattr(struct dentry * dentry,char * buffer,size_t buffer_size)143 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
144 size_t buffer_size)
145 {
146 return -EOPNOTSUPP;
147 }
148 #endif
149
150 #ifdef CONFIG_F2FS_FS_SECURITY
151 extern int f2fs_init_security(struct inode *, struct inode *,
152 const struct qstr *, struct page *);
153 #else
f2fs_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct page * ipage)154 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
155 const struct qstr *qstr, struct page *ipage)
156 {
157 return 0;
158 }
159 #endif
160 #endif /* __F2FS_XATTR_H__ */
161