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 #define EXT4_XATTR_INDEX_SYSTEM 7 25 #define EXT4_XATTR_INDEX_RICHACL 8 26 #define EXT4_XATTR_INDEX_ENCRYPTION 9 27 28 struct ext4_xattr_header { 29 __le32 h_magic; /* magic number for identification */ 30 __le32 h_refcount; /* reference count */ 31 __le32 h_blocks; /* number of disk blocks used */ 32 __le32 h_hash; /* hash value of all attributes */ 33 __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ 34 /* id = inum if refcount=1, blknum otherwise */ 35 __u32 h_reserved[3]; /* zero right now */ 36 }; 37 38 struct ext4_xattr_ibody_header { 39 __le32 h_magic; /* magic number for identification */ 40 }; 41 42 struct ext4_xattr_entry { 43 __u8 e_name_len; /* length of name */ 44 __u8 e_name_index; /* attribute name index */ 45 __le16 e_value_offs; /* offset in disk block of value */ 46 __le32 e_value_block; /* disk block attribute is stored on (n/i) */ 47 __le32 e_value_size; /* size of attribute value */ 48 __le32 e_hash; /* hash value of name and value */ 49 char e_name[0]; /* attribute name */ 50 }; 51 52 #define EXT4_XATTR_PAD_BITS 2 53 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS) 54 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1) 55 #define EXT4_XATTR_LEN(name_len) \ 56 (((name_len) + EXT4_XATTR_ROUND + \ 57 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND) 58 #define EXT4_XATTR_NEXT(entry) \ 59 ((struct ext4_xattr_entry *)( \ 60 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) 61 #define EXT4_XATTR_SIZE(size) \ 62 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) 63 64 #define IHDR(inode, raw_inode) \ 65 ((struct ext4_xattr_ibody_header *) \ 66 ((void *)raw_inode + \ 67 EXT4_GOOD_OLD_INODE_SIZE + \ 68 EXT4_I(inode)->i_extra_isize)) 69 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) 70 71 #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) 72 #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) 73 #define BFIRST(bh) ENTRY(BHDR(bh)+1) 74 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) 75 76 #define EXT4_ZERO_XATTR_VALUE ((void *)-1) 77 78 struct ext4_xattr_info { 79 int name_index; 80 const char *name; 81 const void *value; 82 size_t value_len; 83 }; 84 85 struct ext4_xattr_search { 86 struct ext4_xattr_entry *first; 87 void *base; 88 void *end; 89 struct ext4_xattr_entry *here; 90 int not_found; 91 }; 92 93 struct ext4_xattr_ibody_find { 94 struct ext4_xattr_search s; 95 struct ext4_iloc iloc; 96 }; 97 98 extern const struct xattr_handler ext4_xattr_user_handler; 99 extern const struct xattr_handler ext4_xattr_trusted_handler; 100 extern const struct xattr_handler ext4_xattr_security_handler; 101 102 #define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c" 103 104 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 105 106 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 107 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 108 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 109 110 extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 111 extern void ext4_xattr_put_super(struct super_block *); 112 113 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 114 struct ext4_inode *raw_inode, handle_t *handle); 115 116 extern const struct xattr_handler *ext4_xattr_handlers[]; 117 118 extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 119 struct ext4_xattr_ibody_find *is); 120 extern int ext4_xattr_ibody_get(struct inode *inode, int name_index, 121 const char *name, 122 void *buffer, size_t buffer_size); 123 extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 124 struct ext4_xattr_info *i, 125 struct ext4_xattr_ibody_find *is); 126 127 extern struct mb_cache *ext4_xattr_create_cache(char *name); 128 extern void ext4_xattr_destroy_cache(struct mb_cache *); 129 130 #ifdef CONFIG_EXT4_FS_SECURITY 131 extern int ext4_init_security(handle_t *handle, struct inode *inode, 132 struct inode *dir, const struct qstr *qstr); 133 #else 134 static inline int ext4_init_security(handle_t *handle, struct inode *inode, 135 struct inode *dir, const struct qstr *qstr) 136 { 137 return 0; 138 } 139 #endif 140