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#define F2FS_XATTR_INDEX_VERITY			11
38
39#define F2FS_XATTR_NAME_ENCRYPTION_CONTEXT	"c"
40#define F2FS_XATTR_NAME_VERITY			"v"
41
42struct f2fs_xattr_header {
43	__le32  h_magic;        /* magic number for identification */
44	__le32  h_refcount;     /* reference count */
45	__u32   h_reserved[4];  /* zero right now */
46};
47
48struct f2fs_xattr_entry {
49	__u8    e_name_index;
50	__u8    e_name_len;
51	__le16  e_value_size;   /* size of attribute value */
52	char    e_name[];      /* attribute name */
53};
54
55#define XATTR_HDR(ptr)		((struct f2fs_xattr_header *)(ptr))
56#define XATTR_ENTRY(ptr)	((struct f2fs_xattr_entry *)(ptr))
57#define XATTR_FIRST_ENTRY(ptr)	(XATTR_ENTRY(XATTR_HDR(ptr) + 1))
58#define XATTR_ROUND		(3)
59
60#define XATTR_ALIGN(size)	(((size) + XATTR_ROUND) & ~XATTR_ROUND)
61
62#define ENTRY_SIZE(entry) (XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + \
63			(entry)->e_name_len + le16_to_cpu((entry)->e_value_size)))
64
65#define XATTR_NEXT_ENTRY(entry)	((struct f2fs_xattr_entry *)((char *)(entry) +\
66			ENTRY_SIZE(entry)))
67
68#define IS_XATTR_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
69
70#define list_for_each_xattr(entry, addr) \
71		for (entry = XATTR_FIRST_ENTRY(addr);\
72				!IS_XATTR_LAST_ENTRY(entry);\
73				entry = XATTR_NEXT_ENTRY(entry))
74#define VALID_XATTR_BLOCK_SIZE	(PAGE_SIZE - sizeof(struct node_footer))
75#define XATTR_PADDING_SIZE	(sizeof(__u32))
76#define XATTR_SIZE(i)		((F2FS_I(i)->i_xattr_nid ?		\
77					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#define MIN_INLINE_XATTR_SIZE (sizeof(struct f2fs_xattr_header) / sizeof(__le32))
87#define MAX_INLINE_XATTR_SIZE						\
88			(DEF_ADDRS_PER_INODE -				\
89			F2FS_TOTAL_EXTRA_ATTR_SIZE / sizeof(__le32) -	\
90			DEF_INLINE_RESERVED_SIZE -			\
91			MIN_INLINE_DENTRY_SIZE / sizeof(__le32))
92
93/*
94 * On-disk structure of f2fs_xattr
95 * We use inline xattrs space + 1 block for xattr.
96 *
97 * +--------------------+
98 * | f2fs_xattr_header  |
99 * |                    |
100 * +--------------------+
101 * | f2fs_xattr_entry   |
102 * | .e_name_index = 1  |
103 * | .e_name_len = 3    |
104 * | .e_value_size = 14 |
105 * | .e_name = "foo"    |
106 * | "value_of_xattr"   |<- value_offs = e_name + e_name_len
107 * +--------------------+
108 * | f2fs_xattr_entry   |
109 * | .e_name_index = 4  |
110 * | .e_name = "bar"    |
111 * +--------------------+
112 * |                    |
113 * |        Free        |
114 * |                    |
115 * +--------------------+<- MIN_OFFSET
116 * |   node_footer      |
117 * | (nid, ino, offset) |
118 * +--------------------+
119 *
120 **/
121
122#ifdef CONFIG_F2FS_FS_XATTR
123extern const struct xattr_handler f2fs_xattr_user_handler;
124extern const struct xattr_handler f2fs_xattr_trusted_handler;
125extern const struct xattr_handler f2fs_xattr_advise_handler;
126extern const struct xattr_handler f2fs_xattr_security_handler;
127
128extern const struct xattr_handler * const f2fs_xattr_handlers[];
129
130extern int f2fs_setxattr(struct inode *, int, const char *,
131				const void *, size_t, struct page *, int);
132extern int f2fs_getxattr(struct inode *, int, const char *, void *,
133						size_t, struct page *);
134extern ssize_t f2fs_listxattr(struct dentry *, char *, size_t);
135extern int f2fs_init_xattr_caches(struct f2fs_sb_info *);
136extern void f2fs_destroy_xattr_caches(struct f2fs_sb_info *);
137#else
138
139#define f2fs_xattr_handlers	NULL
140#define f2fs_listxattr		NULL
141static inline int f2fs_setxattr(struct inode *inode, int index,
142		const char *name, const void *value, size_t size,
143		struct page *page, int flags)
144{
145	return -EOPNOTSUPP;
146}
147static inline int f2fs_getxattr(struct inode *inode, int index,
148			const char *name, void *buffer,
149			size_t buffer_size, struct page *dpage)
150{
151	return -EOPNOTSUPP;
152}
153static inline int f2fs_init_xattr_caches(struct f2fs_sb_info *sbi) { return 0; }
154static inline void f2fs_destroy_xattr_caches(struct f2fs_sb_info *sbi) { }
155#endif
156
157#ifdef CONFIG_F2FS_FS_SECURITY
158extern int f2fs_init_security(struct inode *, struct inode *,
159				const struct qstr *, struct page *);
160#else
161static inline int f2fs_init_security(struct inode *inode, struct inode *dir,
162				const struct qstr *qstr, struct page *ipage)
163{
164	return 0;
165}
166#endif
167#endif /* __F2FS_XATTR_H__ */
168