xref: /openbmc/linux/fs/f2fs/xattr.h (revision dd5b2498)
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 MIN_OFFSET(i)		XATTR_ALIGN(inline_xattr_size(i) +	\
75 						VALID_XATTR_BLOCK_SIZE)
76 
77 #define MAX_VALUE_LEN(i)	(MIN_OFFSET(i) -			\
78 				sizeof(struct f2fs_xattr_header) -	\
79 				sizeof(struct f2fs_xattr_entry))
80 
81 #define MAX_INLINE_XATTR_SIZE						\
82 			(DEF_ADDRS_PER_INODE -				\
83 			F2FS_TOTAL_EXTRA_ATTR_SIZE / sizeof(__le32) -	\
84 			DEF_INLINE_RESERVED_SIZE -			\
85 			MIN_INLINE_DENTRY_SIZE / sizeof(__le32))
86 
87 /*
88  * On-disk structure of f2fs_xattr
89  * We use inline xattrs space + 1 block for xattr.
90  *
91  * +--------------------+
92  * | f2fs_xattr_header  |
93  * |                    |
94  * +--------------------+
95  * | f2fs_xattr_entry   |
96  * | .e_name_index = 1  |
97  * | .e_name_len = 3    |
98  * | .e_value_size = 14 |
99  * | .e_name = "foo"    |
100  * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
101  * +--------------------+
102  * | f2fs_xattr_entry   |
103  * | .e_name_index = 4  |
104  * | .e_name = "bar"    |
105  * +--------------------+
106  * |                    |
107  * |        Free        |
108  * |                    |
109  * +--------------------+<- MIN_OFFSET
110  * |   node_footer      |
111  * | (nid, ino, offset) |
112  * +--------------------+
113  *
114  **/
115 
116 #ifdef CONFIG_F2FS_FS_XATTR
117 extern const struct xattr_handler f2fs_xattr_user_handler;
118 extern const struct xattr_handler f2fs_xattr_trusted_handler;
119 extern const struct xattr_handler f2fs_xattr_advise_handler;
120 extern const struct xattr_handler f2fs_xattr_security_handler;
121 
122 extern const struct xattr_handler *f2fs_xattr_handlers[];
123 
124 extern int f2fs_setxattr(struct inode *, int, const char *,
125 				const void *, size_t, struct page *, int);
126 extern int f2fs_getxattr(struct inode *, int, const char *, void *,
127 						size_t, struct page *);
128 extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
129 #else
130 
131 #define f2fs_xattr_handlers	NULL
132 static inline int f2fs_setxattr(struct inode *inode, int index,
133 		const char *name, const void *value, size_t size,
134 		struct page *page, int flags)
135 {
136 	return -EOPNOTSUPP;
137 }
138 static inline int f2fs_getxattr(struct inode *inode, int index,
139 			const char *name, void *buffer,
140 			size_t buffer_size, struct page *dpage)
141 {
142 	return -EOPNOTSUPP;
143 }
144 static inline ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer,
145 		size_t buffer_size)
146 {
147 	return -EOPNOTSUPP;
148 }
149 #endif
150 
151 #ifdef CONFIG_F2FS_FS_SECURITY
152 extern int f2fs_init_security(struct inode *, struct inode *,
153 				const struct qstr *, struct page *);
154 #else
155 static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
156 				const struct qstr *qstr, struct page *ipage)
157 {
158 	return 0;
159 }
160 #endif
161 #endif /* __F2FS_XATTR_H__ */
162