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 25 struct 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 35 struct ext4_xattr_ibody_header { 36 __le32 h_magic; /* magic number for identification */ 37 }; 38 39 struct 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 70 extern const struct xattr_handler ext4_xattr_user_handler; 71 extern const struct xattr_handler ext4_xattr_trusted_handler; 72 extern const struct xattr_handler ext4_xattr_acl_access_handler; 73 extern const struct xattr_handler ext4_xattr_acl_default_handler; 74 extern const struct xattr_handler ext4_xattr_security_handler; 75 76 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 77 78 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 79 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 80 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 81 82 extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 83 extern void ext4_xattr_put_super(struct super_block *); 84 85 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 86 struct ext4_inode *raw_inode, handle_t *handle); 87 88 extern int __init ext4_init_xattr(void); 89 extern void ext4_exit_xattr(void); 90 91 extern const struct xattr_handler *ext4_xattr_handlers[]; 92 93 # else /* CONFIG_EXT4_FS_XATTR */ 94 95 static inline int 96 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 97 void *buffer, size_t size, int flags) 98 { 99 return -EOPNOTSUPP; 100 } 101 102 static inline int 103 ext4_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 } 108 109 static inline int 110 ext4_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 } 115 116 static inline void 117 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) 118 { 119 } 120 121 static inline void 122 ext4_xattr_put_super(struct super_block *sb) 123 { 124 } 125 126 static __init inline int 127 ext4_init_xattr(void) 128 { 129 return 0; 130 } 131 132 static inline void 133 ext4_exit_xattr(void) 134 { 135 } 136 137 static inline int 138 ext4_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 149 extern int ext4_init_security(handle_t *handle, struct inode *inode, 150 struct inode *dir, const struct qstr *qstr); 151 #else 152 static 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 158