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 __u32 h_reserved[4]; /* zero right now */ 31 }; 32 33 struct ext4_xattr_ibody_header { 34 __le32 h_magic; /* magic number for identification */ 35 }; 36 37 struct ext4_xattr_entry { 38 __u8 e_name_len; /* length of name */ 39 __u8 e_name_index; /* attribute name index */ 40 __le16 e_value_offs; /* offset in disk block of value */ 41 __le32 e_value_block; /* disk block attribute is stored on (n/i) */ 42 __le32 e_value_size; /* size of attribute value */ 43 __le32 e_hash; /* hash value of name and value */ 44 char e_name[0]; /* attribute name */ 45 }; 46 47 #define EXT4_XATTR_PAD_BITS 2 48 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS) 49 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1) 50 #define EXT4_XATTR_LEN(name_len) \ 51 (((name_len) + EXT4_XATTR_ROUND + \ 52 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND) 53 #define EXT4_XATTR_NEXT(entry) \ 54 ((struct ext4_xattr_entry *)( \ 55 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) 56 #define EXT4_XATTR_SIZE(size) \ 57 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) 58 59 #define IHDR(inode, raw_inode) \ 60 ((struct ext4_xattr_ibody_header *) \ 61 ((void *)raw_inode + \ 62 EXT4_GOOD_OLD_INODE_SIZE + \ 63 EXT4_I(inode)->i_extra_isize)) 64 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) 65 66 # ifdef CONFIG_EXT4_FS_XATTR 67 68 extern struct xattr_handler ext4_xattr_user_handler; 69 extern struct xattr_handler ext4_xattr_trusted_handler; 70 extern struct xattr_handler ext4_xattr_acl_access_handler; 71 extern struct xattr_handler ext4_xattr_acl_default_handler; 72 extern struct xattr_handler ext4_xattr_security_handler; 73 74 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 75 76 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 77 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 78 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 79 80 extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 81 extern void ext4_xattr_put_super(struct super_block *); 82 83 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 84 struct ext4_inode *raw_inode, handle_t *handle); 85 86 extern int init_ext4_xattr(void); 87 extern void exit_ext4_xattr(void); 88 89 extern struct xattr_handler *ext4_xattr_handlers[]; 90 91 # else /* CONFIG_EXT4_FS_XATTR */ 92 93 static inline int 94 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 95 void *buffer, size_t size, int flags) 96 { 97 return -EOPNOTSUPP; 98 } 99 100 static inline int 101 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 102 const void *value, size_t size, int flags) 103 { 104 return -EOPNOTSUPP; 105 } 106 107 static inline int 108 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 109 const char *name, const void *value, size_t size, int flags) 110 { 111 return -EOPNOTSUPP; 112 } 113 114 static inline void 115 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) 116 { 117 } 118 119 static inline void 120 ext4_xattr_put_super(struct super_block *sb) 121 { 122 } 123 124 static inline int 125 init_ext4_xattr(void) 126 { 127 return 0; 128 } 129 130 static inline void 131 exit_ext4_xattr(void) 132 { 133 } 134 135 static inline int 136 ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 137 struct ext4_inode *raw_inode, handle_t *handle) 138 { 139 return -EOPNOTSUPP; 140 } 141 142 #define ext4_xattr_handlers NULL 143 144 # endif /* CONFIG_EXT4_FS_XATTR */ 145 146 #ifdef CONFIG_EXT4_FS_SECURITY 147 extern int ext4_init_security(handle_t *handle, struct inode *inode, 148 struct inode *dir); 149 #else 150 static inline int ext4_init_security(handle_t *handle, struct inode *inode, 151 struct inode *dir) 152 { 153 return 0; 154 } 155 #endif 156