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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | File: fs/ext4/xattr.h |
ac27a0ec | 3 | |
617ba13b | 4 | On-disk format of extended attributes for the ext4 filesystem. |
ac27a0ec DK |
5 | |
6 | (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> | |
7 | */ | |
8 | ||
9 | #include <linux/xattr.h> | |
10 | ||
11 | /* Magic value in attribute blocks */ | |
617ba13b | 12 | #define EXT4_XATTR_MAGIC 0xEA020000 |
ac27a0ec DK |
13 | |
14 | /* Maximum number of references to one attribute block */ | |
617ba13b | 15 | #define EXT4_XATTR_REFCOUNT_MAX 1024 |
ac27a0ec DK |
16 | |
17 | /* Name indexes */ | |
617ba13b MC |
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 | |
67cf5b09 | 24 | #define EXT4_XATTR_INDEX_SYSTEM 7 |
fd03d8da | 25 | #define EXT4_XATTR_INDEX_RICHACL 8 |
887e2c45 | 26 | #define EXT4_XATTR_INDEX_ENCRYPTION 9 |
3980bd3b | 27 | #define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */ |
617ba13b MC |
28 | |
29 | struct ext4_xattr_header { | |
ac27a0ec DK |
30 | __le32 h_magic; /* magic number for identification */ |
31 | __le32 h_refcount; /* reference count */ | |
32 | __le32 h_blocks; /* number of disk blocks used */ | |
33 | __le32 h_hash; /* hash value of all attributes */ | |
e6153918 DW |
34 | __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ |
35 | /* id = inum if refcount=1, blknum otherwise */ | |
36 | __u32 h_reserved[3]; /* zero right now */ | |
ac27a0ec DK |
37 | }; |
38 | ||
617ba13b | 39 | struct ext4_xattr_ibody_header { |
ac27a0ec DK |
40 | __le32 h_magic; /* magic number for identification */ |
41 | }; | |
42 | ||
617ba13b | 43 | struct ext4_xattr_entry { |
ac27a0ec DK |
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 */ | |
e50e5129 | 47 | __le32 e_value_inum; /* inode in which the value is stored */ |
ac27a0ec DK |
48 | __le32 e_value_size; /* size of attribute value */ |
49 | __le32 e_hash; /* hash value of name and value */ | |
50 | char e_name[0]; /* attribute name */ | |
51 | }; | |
52 | ||
617ba13b MC |
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) \ | |
af5bc92d TT |
60 | ((struct ext4_xattr_entry *)( \ |
61 | (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) | |
617ba13b MC |
62 | #define EXT4_XATTR_SIZE(size) \ |
63 | (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) | |
ac27a0ec | 64 | |
6dd4ee7c KS |
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 | ||
e50e5129 AD |
72 | /* |
73 | * The minimum size of EA value when you start storing it in an external inode | |
74 | * size of block - size of header - size of 1 entry - 4 null bytes | |
75 | */ | |
76 | #define EXT4_XATTR_MIN_LARGE_EA_SIZE(b) \ | |
77 | ((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4) | |
78 | ||
879b3825 TM |
79 | #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) |
80 | #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) | |
81 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) | |
82 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) | |
83 | ||
bd9926e8 | 84 | #define EXT4_ZERO_XATTR_VALUE ((void *)-1) |
879b3825 TM |
85 | |
86 | struct ext4_xattr_info { | |
879b3825 TM |
87 | const char *name; |
88 | const void *value; | |
89 | size_t value_len; | |
e50e5129 AD |
90 | int name_index; |
91 | int in_inode; | |
879b3825 TM |
92 | }; |
93 | ||
94 | struct ext4_xattr_search { | |
95 | struct ext4_xattr_entry *first; | |
96 | void *base; | |
97 | void *end; | |
98 | struct ext4_xattr_entry *here; | |
99 | int not_found; | |
100 | }; | |
101 | ||
102 | struct ext4_xattr_ibody_find { | |
103 | struct ext4_xattr_search s; | |
104 | struct ext4_iloc iloc; | |
105 | }; | |
106 | ||
b6d9029d TE |
107 | struct ext4_xattr_inode_array { |
108 | unsigned int count; /* # of used items in the array */ | |
109 | struct inode *inodes[0]; | |
110 | }; | |
111 | ||
11e27528 SH |
112 | extern const struct xattr_handler ext4_xattr_user_handler; |
113 | extern const struct xattr_handler ext4_xattr_trusted_handler; | |
11e27528 | 114 | extern const struct xattr_handler ext4_xattr_security_handler; |
ac27a0ec | 115 | |
887e2c45 MH |
116 | #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c" |
117 | ||
c755e251 TT |
118 | /* |
119 | * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes. | |
120 | * The first is to signal that there the inline xattrs and data are | |
121 | * taking up so much space that we might as well not keep trying to | |
122 | * expand it. The second is that xattr_sem is taken for writing, so | |
123 | * we shouldn't try to recurse into the inode expansion. For this | |
124 | * second case, we need to make sure that we take save and restore the | |
125 | * NO_EXPAND state flag appropriately. | |
126 | */ | |
127 | static inline void ext4_write_lock_xattr(struct inode *inode, int *save) | |
128 | { | |
129 | down_write(&EXT4_I(inode)->xattr_sem); | |
130 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
131 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
132 | } | |
133 | ||
134 | static inline int ext4_write_trylock_xattr(struct inode *inode, int *save) | |
135 | { | |
136 | if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0) | |
137 | return 0; | |
138 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
139 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
140 | return 1; | |
141 | } | |
142 | ||
143 | static inline void ext4_write_unlock_xattr(struct inode *inode, int *save) | |
144 | { | |
145 | if (*save == 0) | |
146 | ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); | |
147 | up_write(&EXT4_I(inode)->xattr_sem); | |
148 | } | |
149 | ||
617ba13b | 150 | extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); |
ac27a0ec | 151 | |
617ba13b | 152 | extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); |
617ba13b MC |
153 | extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); |
154 | extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); | |
dec214d0 | 155 | extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len, |
af65207c TE |
156 | bool is_create, int *credits); |
157 | extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode, | |
158 | struct buffer_head *block_bh, size_t value_len, | |
159 | bool is_create); | |
ac27a0ec | 160 | |
e50e5129 | 161 | extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode, |
30a7eb97 TE |
162 | struct ext4_xattr_inode_array **array, |
163 | int extra_credits); | |
0421a189 | 164 | extern void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *array); |
ac27a0ec | 165 | |
6dd4ee7c KS |
166 | extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, |
167 | struct ext4_inode *raw_inode, handle_t *handle); | |
168 | ||
11e27528 | 169 | extern const struct xattr_handler *ext4_xattr_handlers[]; |
ac27a0ec | 170 | |
879b3825 TM |
171 | extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
172 | struct ext4_xattr_ibody_find *is); | |
173 | extern int ext4_xattr_ibody_get(struct inode *inode, int name_index, | |
174 | const char *name, | |
175 | void *buffer, size_t buffer_size); | |
0d812f77 TM |
176 | extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, |
177 | struct ext4_xattr_info *i, | |
178 | struct ext4_xattr_ibody_find *is); | |
879b3825 | 179 | |
7a2508e1 JK |
180 | extern struct mb_cache *ext4_xattr_create_cache(void); |
181 | extern void ext4_xattr_destroy_cache(struct mb_cache *); | |
9c191f70 | 182 | |
03010a33 | 183 | #ifdef CONFIG_EXT4_FS_SECURITY |
617ba13b | 184 | extern int ext4_init_security(handle_t *handle, struct inode *inode, |
2a7dba39 | 185 | struct inode *dir, const struct qstr *qstr); |
ac27a0ec | 186 | #else |
617ba13b | 187 | static inline int ext4_init_security(handle_t *handle, struct inode *inode, |
2a7dba39 | 188 | struct inode *dir, const struct qstr *qstr) |
ac27a0ec DK |
189 | { |
190 | return 0; | |
191 | } | |
192 | #endif | |
33d201e0 TE |
193 | |
194 | #ifdef CONFIG_LOCKDEP | |
195 | extern void ext4_xattr_inode_set_class(struct inode *ea_inode); | |
196 | #else | |
197 | static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { } | |
198 | #endif | |
7a9ca53a TE |
199 | |
200 | extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage); |