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1/*
2 File: fs/ext4/xattr.h
3
4 On-disk format of extended attributes for the ext4 filesystem.
5
6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
7*/
8
9#include <linux/xattr.h>
10
11/* Magic value in attribute blocks */
12#define EXT4_XATTR_MAGIC 0xEA020000
13
14/* Maximum number of references to one attribute block */
15#define EXT4_XATTR_REFCOUNT_MAX 1024
16
17/* Name indexes */
18#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
24
25struct ext4_xattr_header {
26 __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 __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
31 /* id = inum if refcount=1, blknum otherwise */
32 __u32 h_reserved[3]; /* zero right now */
33};
34
35struct ext4_xattr_ibody_header {
36 __le32 h_magic; /* magic number for identification */
37};
38
39struct ext4_xattr_entry {
40 __u8 e_name_len; /* length of name */
41 __u8 e_name_index; /* attribute name index */
42 __le16 e_value_offs; /* offset in disk block of value */
43 __le32 e_value_block; /* disk block attribute is stored on (n/i) */
44 __le32 e_value_size; /* size of attribute value */
45 __le32 e_hash; /* hash value of name and value */
46 char e_name[0]; /* attribute name */
47};
48
49#define EXT4_XATTR_PAD_BITS 2
50#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
51#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
52#define EXT4_XATTR_LEN(name_len) \
53 (((name_len) + EXT4_XATTR_ROUND + \
54 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
55#define EXT4_XATTR_NEXT(entry) \
56 ((struct ext4_xattr_entry *)( \
57 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
58#define EXT4_XATTR_SIZE(size) \
59 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
60
61#define IHDR(inode, raw_inode) \
62 ((struct ext4_xattr_ibody_header *) \
63 ((void *)raw_inode + \
64 EXT4_GOOD_OLD_INODE_SIZE + \
65 EXT4_I(inode)->i_extra_isize))
66#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
67
68# ifdef CONFIG_EXT4_FS_XATTR
69
70extern const struct xattr_handler ext4_xattr_user_handler;
71extern const struct xattr_handler ext4_xattr_trusted_handler;
72extern const struct xattr_handler ext4_xattr_acl_access_handler;
73extern const struct xattr_handler ext4_xattr_acl_default_handler;
74extern const struct xattr_handler ext4_xattr_security_handler;
75
76extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
77
78extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
79extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
80extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
81
82extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
83extern void ext4_xattr_put_super(struct super_block *);
84
85extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
86 struct ext4_inode *raw_inode, handle_t *handle);
87
88extern int __init ext4_init_xattr(void);
89extern void ext4_exit_xattr(void);
90
91extern const struct xattr_handler *ext4_xattr_handlers[];
92
93# else /* CONFIG_EXT4_FS_XATTR */
94
95static inline int
96ext4_xattr_get(struct inode *inode, int name_index, const char *name,
97 void *buffer, size_t size, int flags)
98{
99 return -EOPNOTSUPP;
100}
101
102static inline int
103ext4_xattr_set(struct inode *inode, int name_index, const char *name,
104 const void *value, size_t size, int flags)
105{
106 return -EOPNOTSUPP;
107}
108
109static inline int
110ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
111 const char *name, const void *value, size_t size, int flags)
112{
113 return -EOPNOTSUPP;
114}
115
116static inline void
117ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
118{
119}
120
121static inline void
122ext4_xattr_put_super(struct super_block *sb)
123{
124}
125
126static __init inline int
127ext4_init_xattr(void)
128{
129 return 0;
130}
131
132static inline void
133ext4_exit_xattr(void)
134{
135}
136
137static inline int
138ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
139 struct ext4_inode *raw_inode, handle_t *handle)
140{
141 return -EOPNOTSUPP;
142}
143
144#define ext4_xattr_handlers NULL
145
146# endif /* CONFIG_EXT4_FS_XATTR */
147
148#ifdef CONFIG_EXT4_FS_SECURITY
149extern int ext4_init_security(handle_t *handle, struct inode *inode,
150 struct inode *dir, const struct qstr *qstr);
151#else
152static inline int ext4_init_security(handle_t *handle, struct inode *inode,
153 struct inode *dir, const struct qstr *qstr)
154{
155 return 0;
156}
157#endif
1// SPDX-License-Identifier: GPL-2.0
2/*
3 File: fs/ext4/xattr.h
4
5 On-disk format of extended attributes for the ext4 filesystem.
6
7 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
8*/
9
10#include <linux/xattr.h>
11
12/* Magic value in attribute blocks */
13#define EXT4_XATTR_MAGIC 0xEA020000
14
15/* Maximum number of references to one attribute block */
16#define EXT4_XATTR_REFCOUNT_MAX 1024
17
18/* Name indexes */
19#define EXT4_XATTR_INDEX_USER 1
20#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS 2
21#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT 3
22#define EXT4_XATTR_INDEX_TRUSTED 4
23#define EXT4_XATTR_INDEX_LUSTRE 5
24#define EXT4_XATTR_INDEX_SECURITY 6
25#define EXT4_XATTR_INDEX_SYSTEM 7
26#define EXT4_XATTR_INDEX_RICHACL 8
27#define EXT4_XATTR_INDEX_ENCRYPTION 9
28#define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */
29
30struct ext4_xattr_header {
31 __le32 h_magic; /* magic number for identification */
32 __le32 h_refcount; /* reference count */
33 __le32 h_blocks; /* number of disk blocks used */
34 __le32 h_hash; /* hash value of all attributes */
35 __le32 h_checksum; /* crc32c(uuid+blknum+xattrblock) */
36 __u32 h_reserved[3]; /* zero right now */
37};
38
39struct ext4_xattr_ibody_header {
40 __le32 h_magic; /* magic number for identification */
41};
42
43struct ext4_xattr_entry {
44 __u8 e_name_len; /* length of name */
45 __u8 e_name_index; /* attribute name index */
46 __le16 e_value_offs; /* offset in disk block of value */
47 __le32 e_value_inum; /* inode in which the value is stored */
48 __le32 e_value_size; /* size of attribute value */
49 __le32 e_hash; /* hash value of name and value */
50 char e_name[]; /* attribute name */
51};
52
53#define EXT4_XATTR_PAD_BITS 2
54#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
55#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
56#define EXT4_XATTR_LEN(name_len) \
57 (((name_len) + EXT4_XATTR_ROUND + \
58 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
59#define EXT4_XATTR_NEXT(entry) \
60 ((struct ext4_xattr_entry *)( \
61 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
62#define EXT4_XATTR_SIZE(size) \
63 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
64
65#define IHDR(inode, raw_inode) \
66 ((struct ext4_xattr_ibody_header *) \
67 ((void *)raw_inode + \
68 EXT4_GOOD_OLD_INODE_SIZE + \
69 EXT4_I(inode)->i_extra_isize))
70#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
71
72/*
73 * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
74 * for file system consistency errors, we use a somewhat bigger value.
75 * This allows XATTR_SIZE_MAX to grow in the future, but by using this
76 * instead of INT_MAX for certain consistency checks, we don't need to
77 * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is
78 * defined in include/uapi/linux/limits.h, so changing it is going
79 * not going to be trivial....)
80 */
81#define EXT4_XATTR_SIZE_MAX (1 << 24)
82
83/*
84 * The minimum size of EA value when you start storing it in an external inode
85 * size of block - size of header - size of 1 entry - 4 null bytes
86 */
87#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \
88 ((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4)
89
90#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
91#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
92#define BFIRST(bh) ENTRY(BHDR(bh)+1)
93#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
94
95#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
96
97/*
98 * If we want to add an xattr to the inode, we should make sure that
99 * i_extra_isize is not 0 and that the inode size is not less than
100 * EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad.
101 * EXT4_GOOD_OLD_INODE_SIZE extra_isize header entry pad data
102 * |--------------------------|------------|------|---------|---|-------|
103 */
104#define EXT4_INODE_HAS_XATTR_SPACE(inode) \
105 ((EXT4_I(inode)->i_extra_isize != 0) && \
106 (EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize + \
107 sizeof(struct ext4_xattr_ibody_header) + EXT4_XATTR_PAD <= \
108 EXT4_INODE_SIZE((inode)->i_sb)))
109
110struct ext4_xattr_info {
111 const char *name;
112 const void *value;
113 size_t value_len;
114 int name_index;
115 int in_inode;
116};
117
118struct ext4_xattr_search {
119 struct ext4_xattr_entry *first;
120 void *base;
121 void *end;
122 struct ext4_xattr_entry *here;
123 int not_found;
124};
125
126struct ext4_xattr_ibody_find {
127 struct ext4_xattr_search s;
128 struct ext4_iloc iloc;
129};
130
131struct ext4_xattr_inode_array {
132 unsigned int count;
133 struct inode *inodes[] __counted_by(count);
134};
135
136extern const struct xattr_handler ext4_xattr_user_handler;
137extern const struct xattr_handler ext4_xattr_trusted_handler;
138extern const struct xattr_handler ext4_xattr_security_handler;
139extern const struct xattr_handler ext4_xattr_hurd_handler;
140
141#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
142
143/*
144 * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
145 * The first is to signal that there the inline xattrs and data are
146 * taking up so much space that we might as well not keep trying to
147 * expand it. The second is that xattr_sem is taken for writing, so
148 * we shouldn't try to recurse into the inode expansion. For this
149 * second case, we need to make sure that we take save and restore the
150 * NO_EXPAND state flag appropriately.
151 */
152static inline void ext4_write_lock_xattr(struct inode *inode, int *save)
153{
154 down_write(&EXT4_I(inode)->xattr_sem);
155 *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
156 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
157}
158
159static inline int ext4_write_trylock_xattr(struct inode *inode, int *save)
160{
161 if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
162 return 0;
163 *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
164 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
165 return 1;
166}
167
168static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
169{
170 if (*save == 0)
171 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
172 up_write(&EXT4_I(inode)->xattr_sem);
173}
174
175extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
176
177extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
178extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
179extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
180extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
181 bool is_create, int *credits);
182extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
183 struct buffer_head *block_bh, size_t value_len,
184 bool is_create);
185
186extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
187 struct ext4_xattr_inode_array **array,
188 int extra_credits);
189extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array);
190
191extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
192 struct ext4_inode *raw_inode, handle_t *handle);
193extern void ext4_evict_ea_inode(struct inode *inode);
194
195extern const struct xattr_handler * const ext4_xattr_handlers[];
196
197extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
198 struct ext4_xattr_ibody_find *is);
199extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
200 const char *name,
201 void *buffer, size_t buffer_size);
202extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
203 struct ext4_xattr_info *i,
204 struct ext4_xattr_ibody_find *is);
205
206extern struct mb_cache *ext4_xattr_create_cache(void);
207extern void ext4_xattr_destroy_cache(struct mb_cache *);
208
209#ifdef CONFIG_EXT4_FS_SECURITY
210extern int ext4_init_security(handle_t *handle, struct inode *inode,
211 struct inode *dir, const struct qstr *qstr);
212#else
213static inline int ext4_init_security(handle_t *handle, struct inode *inode,
214 struct inode *dir, const struct qstr *qstr)
215{
216 return 0;
217}
218#endif
219
220#ifdef CONFIG_LOCKDEP
221extern void ext4_xattr_inode_set_class(struct inode *ea_inode);
222#else
223static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { }
224#endif
225
226extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage);