Commit | Line | Data |
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f5166768 | 1 | // SPDX-License-Identifier: GPL-2.0 |
ac27a0ec | 2 | /* |
617ba13b | 3 | File: fs/ext4/xattr.h |
ac27a0ec | 4 | |
617ba13b | 5 | On-disk format of extended attributes for the ext4 filesystem. |
ac27a0ec DK |
6 | |
7 | (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> | |
8 | */ | |
9 | ||
10 | #include <linux/xattr.h> | |
11 | ||
12 | /* Magic value in attribute blocks */ | |
617ba13b | 13 | #define EXT4_XATTR_MAGIC 0xEA020000 |
ac27a0ec DK |
14 | |
15 | /* Maximum number of references to one attribute block */ | |
617ba13b | 16 | #define EXT4_XATTR_REFCOUNT_MAX 1024 |
ac27a0ec DK |
17 | |
18 | /* Name indexes */ | |
617ba13b MC |
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 | |
67cf5b09 | 25 | #define EXT4_XATTR_INDEX_SYSTEM 7 |
fd03d8da | 26 | #define EXT4_XATTR_INDEX_RICHACL 8 |
887e2c45 | 27 | #define EXT4_XATTR_INDEX_ENCRYPTION 9 |
3980bd3b | 28 | #define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */ |
617ba13b MC |
29 | |
30 | struct ext4_xattr_header { | |
ac27a0ec DK |
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 */ | |
e6153918 DW |
35 | __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ |
36 | /* id = inum if refcount=1, blknum otherwise */ | |
37 | __u32 h_reserved[3]; /* zero right now */ | |
ac27a0ec DK |
38 | }; |
39 | ||
617ba13b | 40 | struct ext4_xattr_ibody_header { |
ac27a0ec DK |
41 | __le32 h_magic; /* magic number for identification */ |
42 | }; | |
43 | ||
617ba13b | 44 | struct ext4_xattr_entry { |
ac27a0ec DK |
45 | __u8 e_name_len; /* length of name */ |
46 | __u8 e_name_index; /* attribute name index */ | |
47 | __le16 e_value_offs; /* offset in disk block of value */ | |
e50e5129 | 48 | __le32 e_value_inum; /* inode in which the value is stored */ |
ac27a0ec DK |
49 | __le32 e_value_size; /* size of attribute value */ |
50 | __le32 e_hash; /* hash value of name and value */ | |
47b10306 | 51 | char e_name[]; /* attribute name */ |
ac27a0ec DK |
52 | }; |
53 | ||
617ba13b MC |
54 | #define EXT4_XATTR_PAD_BITS 2 |
55 | #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS) | |
56 | #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1) | |
57 | #define EXT4_XATTR_LEN(name_len) \ | |
58 | (((name_len) + EXT4_XATTR_ROUND + \ | |
59 | sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND) | |
60 | #define EXT4_XATTR_NEXT(entry) \ | |
af5bc92d TT |
61 | ((struct ext4_xattr_entry *)( \ |
62 | (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) | |
617ba13b MC |
63 | #define EXT4_XATTR_SIZE(size) \ |
64 | (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) | |
ac27a0ec | 65 | |
6dd4ee7c KS |
66 | #define IHDR(inode, raw_inode) \ |
67 | ((struct ext4_xattr_ibody_header *) \ | |
68 | ((void *)raw_inode + \ | |
69 | EXT4_GOOD_OLD_INODE_SIZE + \ | |
70 | EXT4_I(inode)->i_extra_isize)) | |
71 | #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) | |
72 | ||
54dd0e0a TT |
73 | /* |
74 | * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking | |
75 | * for file system consistency errors, we use a somewhat bigger value. | |
76 | * This allows XATTR_SIZE_MAX to grow in the future, but by using this | |
77 | * instead of INT_MAX for certain consistency checks, we don't need to | |
78 | * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is | |
79 | * defined in include/uapi/linux/limits.h, so changing it is going | |
80 | * not going to be trivial....) | |
81 | */ | |
82 | #define EXT4_XATTR_SIZE_MAX (1 << 24) | |
83 | ||
e50e5129 AD |
84 | /* |
85 | * The minimum size of EA value when you start storing it in an external inode | |
86 | * size of block - size of header - size of 1 entry - 4 null bytes | |
c64a9299 | 87 | */ |
e50e5129 AD |
88 | #define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \ |
89 | ((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4) | |
90 | ||
879b3825 TM |
91 | #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) |
92 | #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) | |
93 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) | |
94 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) | |
95 | ||
bd9926e8 | 96 | #define EXT4_ZERO_XATTR_VALUE ((void *)-1) |
879b3825 | 97 | |
179b1415 BL |
98 | /* |
99 | * If we want to add an xattr to the inode, we should make sure that | |
100 | * i_extra_isize is not 0 and that the inode size is not less than | |
101 | * EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad. | |
102 | * EXT4_GOOD_OLD_INODE_SIZE extra_isize header entry pad data | |
103 | * |--------------------------|------------|------|---------|---|-------| | |
104 | */ | |
105 | #define EXT4_INODE_HAS_XATTR_SPACE(inode) \ | |
106 | ((EXT4_I(inode)->i_extra_isize != 0) && \ | |
107 | (EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize + \ | |
108 | sizeof(struct ext4_xattr_ibody_header) + EXT4_XATTR_PAD <= \ | |
109 | EXT4_INODE_SIZE((inode)->i_sb))) | |
110 | ||
879b3825 | 111 | struct ext4_xattr_info { |
879b3825 TM |
112 | const char *name; |
113 | const void *value; | |
114 | size_t value_len; | |
e50e5129 AD |
115 | int name_index; |
116 | int in_inode; | |
879b3825 TM |
117 | }; |
118 | ||
119 | struct ext4_xattr_search { | |
120 | struct ext4_xattr_entry *first; | |
121 | void *base; | |
122 | void *end; | |
123 | struct ext4_xattr_entry *here; | |
124 | int not_found; | |
125 | }; | |
126 | ||
127 | struct ext4_xattr_ibody_find { | |
128 | struct ext4_xattr_search s; | |
129 | struct ext4_iloc iloc; | |
130 | }; | |
131 | ||
b6d9029d TE |
132 | struct ext4_xattr_inode_array { |
133 | unsigned int count; /* # of used items in the array */ | |
47b10306 | 134 | struct inode *inodes[]; |
b6d9029d TE |
135 | }; |
136 | ||
11e27528 SH |
137 | extern const struct xattr_handler ext4_xattr_user_handler; |
138 | extern const struct xattr_handler ext4_xattr_trusted_handler; | |
11e27528 | 139 | extern const struct xattr_handler ext4_xattr_security_handler; |
88ee9d57 | 140 | extern const struct xattr_handler ext4_xattr_hurd_handler; |
ac27a0ec | 141 | |
887e2c45 MH |
142 | #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c" |
143 | ||
c755e251 TT |
144 | /* |
145 | * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes. | |
146 | * The first is to signal that there the inline xattrs and data are | |
147 | * taking up so much space that we might as well not keep trying to | |
148 | * expand it. The second is that xattr_sem is taken for writing, so | |
149 | * we shouldn't try to recurse into the inode expansion. For this | |
150 | * second case, we need to make sure that we take save and restore the | |
151 | * NO_EXPAND state flag appropriately. | |
152 | */ | |
153 | static inline void ext4_write_lock_xattr(struct inode *inode, int *save) | |
154 | { | |
155 | down_write(&EXT4_I(inode)->xattr_sem); | |
156 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
157 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
158 | } | |
159 | ||
160 | static inline int ext4_write_trylock_xattr(struct inode *inode, int *save) | |
161 | { | |
162 | if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0) | |
163 | return 0; | |
164 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
165 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
166 | return 1; | |
167 | } | |
168 | ||
169 | static inline void ext4_write_unlock_xattr(struct inode *inode, int *save) | |
170 | { | |
171 | if (*save == 0) | |
172 | ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
173 | up_write(&EXT4_I(inode)->xattr_sem); | |
174 | } | |
175 | ||
617ba13b | 176 | extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); |
ac27a0ec | 177 | |
617ba13b | 178 | extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); |
617ba13b MC |
179 | extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); |
180 | extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); | |
dec214d0 | 181 | extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len, |
af65207c TE |
182 | bool is_create, int *credits); |
183 | extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, | |
184 | struct buffer_head *block_bh, size_t value_len, | |
185 | bool is_create); | |
ac27a0ec | 186 | |
e50e5129 | 187 | extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, |
30a7eb97 TE |
188 | struct ext4_xattr_inode_array **array, |
189 | int extra_credits); | |
0421a189 | 190 | extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array); |
ac27a0ec | 191 | |
6dd4ee7c KS |
192 | extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, |
193 | struct ext4_inode *raw_inode, handle_t *handle); | |
6bc0d63d | 194 | extern void ext4_evict_ea_inode(struct inode *inode); |
6dd4ee7c | 195 | |
11e27528 | 196 | extern const struct xattr_handler *ext4_xattr_handlers[]; |
ac27a0ec | 197 | |
879b3825 TM |
198 | extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
199 | struct ext4_xattr_ibody_find *is); | |
200 | extern int ext4_xattr_ibody_get(struct inode *inode, int name_index, | |
201 | const char *name, | |
202 | void *buffer, size_t buffer_size); | |
310c097c RH |
203 | extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, |
204 | struct ext4_xattr_info *i, | |
205 | struct ext4_xattr_ibody_find *is); | |
879b3825 | 206 | |
7a2508e1 JK |
207 | extern struct mb_cache *ext4_xattr_create_cache(void); |
208 | extern void ext4_xattr_destroy_cache(struct mb_cache *); | |
9c191f70 | 209 | |
03010a33 | 210 | #ifdef CONFIG_EXT4_FS_SECURITY |
617ba13b | 211 | extern int ext4_init_security(handle_t *handle, struct inode *inode, |
2a7dba39 | 212 | struct inode *dir, const struct qstr *qstr); |
ac27a0ec | 213 | #else |
617ba13b | 214 | static inline int ext4_init_security(handle_t *handle, struct inode *inode, |
2a7dba39 | 215 | struct inode *dir, const struct qstr *qstr) |
ac27a0ec DK |
216 | { |
217 | return 0; | |
218 | } | |
219 | #endif | |
33d201e0 TE |
220 | |
221 | #ifdef CONFIG_LOCKDEP | |
222 | extern void ext4_xattr_inode_set_class(struct inode *ea_inode); | |
223 | #else | |
224 | static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { } | |
225 | #endif | |
7a9ca53a TE |
226 | |
227 | extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage); |