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 # ifdef CONFIG_EXT4DEV_FS_XATTR 60 61 extern struct xattr_handler ext4_xattr_user_handler; 62 extern struct xattr_handler ext4_xattr_trusted_handler; 63 extern struct xattr_handler ext4_xattr_acl_access_handler; 64 extern struct xattr_handler ext4_xattr_acl_default_handler; 65 extern struct xattr_handler ext4_xattr_security_handler; 66 67 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 68 69 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 70 extern int ext4_xattr_list(struct inode *, char *, size_t); 71 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 72 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 73 74 extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 75 extern void ext4_xattr_put_super(struct super_block *); 76 77 extern int init_ext4_xattr(void); 78 extern void exit_ext4_xattr(void); 79 80 extern struct xattr_handler *ext4_xattr_handlers[]; 81 82 # else /* CONFIG_EXT4DEV_FS_XATTR */ 83 84 static inline int 85 ext4_xattr_get(struct inode *inode, int name_index, const char *name, 86 void *buffer, size_t size, int flags) 87 { 88 return -EOPNOTSUPP; 89 } 90 91 static inline int 92 ext4_xattr_list(struct inode *inode, void *buffer, size_t size) 93 { 94 return -EOPNOTSUPP; 95 } 96 97 static inline int 98 ext4_xattr_set(struct inode *inode, int name_index, const char *name, 99 const void *value, size_t size, int flags) 100 { 101 return -EOPNOTSUPP; 102 } 103 104 static inline int 105 ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 106 const char *name, const void *value, size_t size, int flags) 107 { 108 return -EOPNOTSUPP; 109 } 110 111 static inline void 112 ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) 113 { 114 } 115 116 static inline void 117 ext4_xattr_put_super(struct super_block *sb) 118 { 119 } 120 121 static inline int 122 init_ext4_xattr(void) 123 { 124 return 0; 125 } 126 127 static inline void 128 exit_ext4_xattr(void) 129 { 130 } 131 132 #define ext4_xattr_handlers NULL 133 134 # endif /* CONFIG_EXT4DEV_FS_XATTR */ 135 136 #ifdef CONFIG_EXT4DEV_FS_SECURITY 137 extern int ext4_init_security(handle_t *handle, struct inode *inode, 138 struct inode *dir); 139 #else 140 static inline int ext4_init_security(handle_t *handle, struct inode *inode, 141 struct inode *dir) 142 { 143 return 0; 144 } 145 #endif 146