Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 1 | /* |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 2 | File: fs/ext4/xattr.h |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 3 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 4 | On-disk format of extended attributes for the ext4 filesystem. |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 5 | |
| 6 | (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/xattr.h> |
| 10 | |
| 11 | /* Magic value in attribute blocks */ |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 12 | #define EXT4_XATTR_MAGIC 0xEA020000 |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 13 | |
| 14 | /* Maximum number of references to one attribute block */ |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 15 | #define EXT4_XATTR_REFCOUNT_MAX 1024 |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 16 | |
| 17 | /* Name indexes */ |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 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 |
Tao Ma | 67cf5b0 | 2012-12-10 14:04:46 -0500 | [diff] [blame] | 24 | #define EXT4_XATTR_INDEX_SYSTEM 7 |
Theodore Ts'o | fd03d8d | 2013-04-18 14:53:15 -0400 | [diff] [blame] | 25 | #define EXT4_XATTR_INDEX_RICHACL 8 |
Michael Halcrow | 887e2c4 | 2015-04-11 07:47:00 -0400 | [diff] [blame] | 26 | #define EXT4_XATTR_INDEX_ENCRYPTION 9 |
Theodore Ts'o | 3980bd3 | 2016-07-31 23:38:36 -0400 | [diff] [blame] | 27 | #define EXT4_XATTR_INDEX_HURD 10 /* Reserved for Hurd */ |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 28 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 29 | struct ext4_xattr_header { |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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 */ |
Darrick J. Wong | e615391 | 2012-04-29 18:23:10 -0400 | [diff] [blame] | 34 | __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ |
| 35 | /* id = inum if refcount=1, blknum otherwise */ |
| 36 | __u32 h_reserved[3]; /* zero right now */ |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 37 | }; |
| 38 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 39 | struct ext4_xattr_ibody_header { |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 40 | __le32 h_magic; /* magic number for identification */ |
| 41 | }; |
| 42 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 43 | struct ext4_xattr_entry { |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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_block; /* disk block attribute is stored on (n/i) */ |
| 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 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 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) \ |
Theodore Ts'o | af5bc92 | 2008-09-08 22:25:24 -0400 | [diff] [blame] | 60 | ((struct ext4_xattr_entry *)( \ |
| 61 | (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 62 | #define EXT4_XATTR_SIZE(size) \ |
| 63 | (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 64 | |
Kalpak Shah | 6dd4ee7 | 2007-07-18 09:19:57 -0400 | [diff] [blame] | 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 | |
Tao Ma | 879b382 | 2012-12-05 10:28:46 -0500 | [diff] [blame] | 72 | #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) |
| 73 | #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) |
| 74 | #define BFIRST(bh) ENTRY(BHDR(bh)+1) |
| 75 | #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) |
| 76 | |
Theodore Ts'o | bd9926e | 2012-12-11 03:31:49 -0500 | [diff] [blame] | 77 | #define EXT4_ZERO_XATTR_VALUE ((void *)-1) |
Tao Ma | 879b382 | 2012-12-05 10:28:46 -0500 | [diff] [blame] | 78 | |
| 79 | struct ext4_xattr_info { |
| 80 | int name_index; |
| 81 | const char *name; |
| 82 | const void *value; |
| 83 | size_t value_len; |
| 84 | }; |
| 85 | |
| 86 | struct ext4_xattr_search { |
| 87 | struct ext4_xattr_entry *first; |
| 88 | void *base; |
| 89 | void *end; |
| 90 | struct ext4_xattr_entry *here; |
| 91 | int not_found; |
| 92 | }; |
| 93 | |
| 94 | struct ext4_xattr_ibody_find { |
| 95 | struct ext4_xattr_search s; |
| 96 | struct ext4_iloc iloc; |
| 97 | }; |
| 98 | |
Stephen Hemminger | 11e2752 | 2010-05-13 17:53:18 -0700 | [diff] [blame] | 99 | extern const struct xattr_handler ext4_xattr_user_handler; |
| 100 | extern const struct xattr_handler ext4_xattr_trusted_handler; |
Stephen Hemminger | 11e2752 | 2010-05-13 17:53:18 -0700 | [diff] [blame] | 101 | extern const struct xattr_handler ext4_xattr_security_handler; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 102 | |
Michael Halcrow | 887e2c4 | 2015-04-11 07:47:00 -0400 | [diff] [blame] | 103 | #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c" |
| 104 | |
Theodore Ts'o | c755e25 | 2017-01-11 21:50:46 -0500 | [diff] [blame] | 105 | /* |
| 106 | * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes. |
| 107 | * The first is to signal that there the inline xattrs and data are |
| 108 | * taking up so much space that we might as well not keep trying to |
| 109 | * expand it. The second is that xattr_sem is taken for writing, so |
| 110 | * we shouldn't try to recurse into the inode expansion. For this |
| 111 | * second case, we need to make sure that we take save and restore the |
| 112 | * NO_EXPAND state flag appropriately. |
| 113 | */ |
| 114 | static inline void ext4_write_lock_xattr(struct inode *inode, int *save) |
| 115 | { |
| 116 | down_write(&EXT4_I(inode)->xattr_sem); |
| 117 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); |
| 118 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); |
| 119 | } |
| 120 | |
| 121 | static inline int ext4_write_trylock_xattr(struct inode *inode, int *save) |
| 122 | { |
| 123 | if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0) |
| 124 | return 0; |
| 125 | *save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); |
| 126 | ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); |
| 127 | return 1; |
| 128 | } |
| 129 | |
| 130 | static inline void ext4_write_unlock_xattr(struct inode *inode, int *save) |
| 131 | { |
| 132 | if (*save == 0) |
| 133 | ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); |
| 134 | up_write(&EXT4_I(inode)->xattr_sem); |
| 135 | } |
| 136 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 137 | extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 138 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 139 | extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 140 | extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); |
| 141 | extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 142 | |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 143 | extern void ext4_xattr_delete_inode(handle_t *, struct inode *); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 144 | |
Kalpak Shah | 6dd4ee7 | 2007-07-18 09:19:57 -0400 | [diff] [blame] | 145 | extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, |
| 146 | struct ext4_inode *raw_inode, handle_t *handle); |
| 147 | |
Stephen Hemminger | 11e2752 | 2010-05-13 17:53:18 -0700 | [diff] [blame] | 148 | extern const struct xattr_handler *ext4_xattr_handlers[]; |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 149 | |
Tao Ma | 879b382 | 2012-12-05 10:28:46 -0500 | [diff] [blame] | 150 | extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, |
| 151 | struct ext4_xattr_ibody_find *is); |
| 152 | extern int ext4_xattr_ibody_get(struct inode *inode, int name_index, |
| 153 | const char *name, |
| 154 | void *buffer, size_t buffer_size); |
Tao Ma | 0d812f7 | 2012-12-10 14:06:02 -0500 | [diff] [blame] | 155 | extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, |
| 156 | struct ext4_xattr_info *i, |
| 157 | struct ext4_xattr_ibody_find *is); |
Tao Ma | 879b382 | 2012-12-05 10:28:46 -0500 | [diff] [blame] | 158 | |
Jan Kara | 7a2508e | 2016-02-22 22:35:22 -0500 | [diff] [blame] | 159 | extern struct mb_cache *ext4_xattr_create_cache(void); |
| 160 | extern void ext4_xattr_destroy_cache(struct mb_cache *); |
T Makphaibulchoke | 9c191f7 | 2014-03-18 19:24:49 -0400 | [diff] [blame] | 161 | |
Theodore Ts'o | 03010a3 | 2008-10-10 20:02:48 -0400 | [diff] [blame] | 162 | #ifdef CONFIG_EXT4_FS_SECURITY |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 163 | extern int ext4_init_security(handle_t *handle, struct inode *inode, |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 164 | struct inode *dir, const struct qstr *qstr); |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 165 | #else |
Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 166 | static inline int ext4_init_security(handle_t *handle, struct inode *inode, |
Eric Paris | 2a7dba3 | 2011-02-01 11:05:39 -0500 | [diff] [blame] | 167 | struct inode *dir, const struct qstr *qstr) |
Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 168 | { |
| 169 | return 0; |
| 170 | } |
| 171 | #endif |