xref: /linux/fs/f2fs/xattr.h (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * fs/f2fs/xattr.h
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  *
8  * Portions of this code from linux/fs/ext2/xattr.h
9  *
10  * On-disk format of extended attributes for the ext2 filesystem.
11  *
12  * (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
13  */
14 #ifndef __F2FS_XATTR_H__
15 #define __F2FS_XATTR_H__
16 
17 #include <linux/init.h>
18 #include <linux/xattr.h>
19 
20 /* Magic value in attribute blocks */
21 #define F2FS_XATTR_MAGIC                0xF2F52011
22 
23 /* Maximum number of references to one attribute block */
24 #define F2FS_XATTR_REFCOUNT_MAX         1024
25 
26 /* Name indexes */
27 #define F2FS_SYSTEM_ADVISE_NAME			"system.advise"
28 #define F2FS_XATTR_INDEX_USER			1
29 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
30 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3
31 #define F2FS_XATTR_INDEX_TRUSTED		4
32 #define F2FS_XATTR_INDEX_LUSTRE			5
33 #define F2FS_XATTR_INDEX_SECURITY		6
34 #define F2FS_XATTR_INDEX_ADVISE			7
35 /* Should be same as EXT4_XATTR_INDEX_ENCRYPTION */
36 #define F2FS_XATTR_INDEX_ENCRYPTION		9
37 
38 #define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT	"c"
39 
40 struct f2fs_xattr_header {
41 	__le32  h_magic;        /* magic number for identification */
42 	__le32  h_refcount;     /* reference count */
43 	__u32   h_reserved[4];  /* zero right now */
44 };
45 
46 struct f2fs_xattr_entry {
47 	__u8    e_name_index;
48 	__u8    e_name_len;
49 	__le16  e_value_size;   /* size of attribute value */
50 	char    e_name[0];      /* attribute name */
51 };
52 
53 #define XATTR_HDR(ptr)		((struct f2fs_xattr_header *)(ptr))
54 #define XATTR_ENTRY(ptr)	((struct f2fs_xattr_entry *)(ptr))
55 #define XATTR_FIRST_ENTRY(ptr)	(XATTR_ENTRY(XATTR_HDR(ptr) + 1))
56 #define XATTR_ROUND		(3)
57 
58 #define XATTR_ALIGN(size)	(((size) + XATTR_ROUND) & ~XATTR_ROUND)
59 
60 #define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
61 			(entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
62 
63 #define XATTR_NEXT_ENTRY(entry)	((struct f2fs_xattr_entry *)((char *)(entry) +\
64 			ENTRY_SIZE(entry)))
65 
66 #define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
67 
68 #define list_for_each_xattr(entry, addr) \
69 		for (entry = XATTR_FIRST_ENTRY(addr);\
70 				!IS_XATTR_LAST_ENTRY(entry);\
71 				entry = XATTR_NEXT_ENTRY(entry))
72 #define VALID_XATTR_BLOCK_SIZE	(PAGE_SIZE - sizeof(struct node_footer))
73 #define XATTR_PADDING_SIZE	(sizeof(__u32))
74 #define XATTR_SIZE(x,i)		(((x) ? VALID_XATTR_BLOCK_SIZE : 0) +	\
75 						(inline_xattr_size(i)))
76 #define MIN_OFFSET(i)		XATTR_ALIGN(inline_xattr_size(i) +	\
77 						VALID_XATTR_BLOCK_SIZE)
78 
79 #define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
80 				sizeof(struct f2fs_xattr_header) -	\
81 				sizeof(struct f2fs_xattr_entry))
82 
83 #define MAX_INLINE_XATTR_SIZE						\
84 			(DEF_ADDRS_PER_INODE -				\
85 			F2FS_TOTAL_EXTRA_ATTR_SIZE / sizeof(__le32) -	\
86 			DEF_INLINE_RESERVED_SIZE -			\
87 			MIN_INLINE_DENTRY_SIZE / sizeof(__le32))
88 
89 /*
90  * On-disk structure of f2fs_xattr
91  * We use inline xattrs space + 1 block for xattr.
92  *
93  * +--------------------+
94  * | f2fs_xattr_header  |
95  * |                    |
96  * +--------------------+
97  * | f2fs_xattr_entry   |
98  * | .e_name_index = 1  |
99  * | .e_name_len = 3    |
100  * | .e_value_size = 14 |
101  * | .e_name = "foo"    |
102  * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
103  * +--------------------+
104  * | f2fs_xattr_entry   |
105  * | .e_name_index = 4  |
106  * | .e_name = "bar"    |
107  * +--------------------+
108  * |                    |
109  * |        Free        |
110  * |                    |
111  * +--------------------+<- MIN_OFFSET
112  * |   node_footer      |
113  * | (nid, ino, offset) |
114  * +--------------------+
115  *
116  **/
117 
118 #ifdef CONFIG_F2FS_FS_XATTR
119 extern const struct xattr_handler f2fs_xattr_user_handler;
120 extern const struct xattr_handler f2fs_xattr_trusted_handler;
121 extern const struct xattr_handler f2fs_xattr_advise_handler;
122 extern const struct xattr_handler f2fs_xattr_security_handler;
123 
124 extern const struct xattr_handler *f2fs_xattr_handlers[];
125 
126 extern int f2fs_setxattr(struct inode *, int, const char *,
127 				const void *, size_t, struct page *, int);
128 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
129 						size_t, struct page *);
130 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
131 #else
132 
133 #define f2fs_xattr_handlers	NULL
134 static inline int f2fs_setxattr(struct inode *inode, int index,
135 		const char *name, const void *value, size_t size,
136 		struct page *page, int flags)
137 {
138 	return -EOPNOTSUPP;
139 }
140 static inline int f2fs_getxattr(struct inode *inode, int index,
141 			const char *name, void *buffer,
142 			size_t buffer_size, struct page *dpage)
143 {
144 	return -EOPNOTSUPP;
145 }
146 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
147 		size_t buffer_size)
148 {
149 	return -EOPNOTSUPP;
150 }
151 #endif
152 
153 #ifdef CONFIG_F2FS_FS_SECURITY
154 extern int f2fs_init_security(struct inode *, struct inode *,
155 				const struct qstr *, struct page *);
156 #else
157 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
158 				const struct qstr *qstr, struct page *ipage)
159 {
160 	return 0;
161 }
162 #endif
163 #endif /* __F2FS_XATTR_H__ */
164