1 /* 2 File: linux/ext2_xattr.h 3 4 On-disk format of extended attributes for the ext2 filesystem. 5 6 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org> 7 */ 8 9 #include <linux/init.h> 10 #include <linux/xattr.h> 11 12 /* Magic value in attribute blocks */ 13 #define EXT2_XATTR_MAGIC 0xEA020000 14 15 /* Maximum number of references to one attribute block */ 16 #define EXT2_XATTR_REFCOUNT_MAX 1024 17 18 /* Name indexes */ 19 #define EXT2_XATTR_INDEX_USER 1 20 #define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2 21 #define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3 22 #define EXT2_XATTR_INDEX_TRUSTED 4 23 #define EXT2_XATTR_INDEX_LUSTRE 5 24 #define EXT2_XATTR_INDEX_SECURITY 6 25 26 struct ext2_xattr_header { 27 __le32 h_magic; /* magic number for identification */ 28 __le32 h_refcount; /* reference count */ 29 __le32 h_blocks; /* number of disk blocks used */ 30 __le32 h_hash; /* hash value of all attributes */ 31 __u32 h_reserved[4]; /* zero right now */ 32 }; 33 34 struct ext2_xattr_entry { 35 __u8 e_name_len; /* length of name */ 36 __u8 e_name_index; /* attribute name index */ 37 __le16 e_value_offs; /* offset in disk block of value */ 38 __le32 e_value_block; /* disk block attribute is stored on (n/i) */ 39 __le32 e_value_size; /* size of attribute value */ 40 __le32 e_hash; /* hash value of name and value */ 41 char e_name[0]; /* attribute name */ 42 }; 43 44 #define EXT2_XATTR_PAD_BITS 2 45 #define EXT2_XATTR_PAD (1<<EXT2_XATTR_PAD_BITS) 46 #define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1) 47 #define EXT2_XATTR_LEN(name_len) \ 48 (((name_len) + EXT2_XATTR_ROUND + \ 49 sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND) 50 #define EXT2_XATTR_NEXT(entry) \ 51 ( (struct ext2_xattr_entry *)( \ 52 (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) ) 53 #define EXT2_XATTR_SIZE(size) \ 54 (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND) 55 56 # ifdef CONFIG_EXT2_FS_XATTR 57 58 extern const struct xattr_handler ext2_xattr_user_handler; 59 extern const struct xattr_handler ext2_xattr_trusted_handler; 60 extern const struct xattr_handler ext2_xattr_acl_access_handler; 61 extern const struct xattr_handler ext2_xattr_acl_default_handler; 62 extern const struct xattr_handler ext2_xattr_security_handler; 63 64 extern ssize_t ext2_listxattr(struct dentry *, char *, size_t); 65 66 extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t); 67 extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 68 69 extern void ext2_xattr_delete_inode(struct inode *); 70 extern void ext2_xattr_put_super(struct super_block *); 71 72 extern int init_ext2_xattr(void); 73 extern void exit_ext2_xattr(void); 74 75 extern const struct xattr_handler *ext2_xattr_handlers[]; 76 77 # else /* CONFIG_EXT2_FS_XATTR */ 78 79 static inline int 80 ext2_xattr_get(struct inode *inode, int name_index, 81 const char *name, void *buffer, size_t size) 82 { 83 return -EOPNOTSUPP; 84 } 85 86 static inline int 87 ext2_xattr_set(struct inode *inode, int name_index, const char *name, 88 const void *value, size_t size, int flags) 89 { 90 return -EOPNOTSUPP; 91 } 92 93 static inline void 94 ext2_xattr_delete_inode(struct inode *inode) 95 { 96 } 97 98 static inline void 99 ext2_xattr_put_super(struct super_block *sb) 100 { 101 } 102 103 static inline int 104 init_ext2_xattr(void) 105 { 106 return 0; 107 } 108 109 static inline void 110 exit_ext2_xattr(void) 111 { 112 } 113 114 #define ext2_xattr_handlers NULL 115 116 # endif /* CONFIG_EXT2_FS_XATTR */ 117 118 #ifdef CONFIG_EXT2_FS_SECURITY 119 extern int ext2_init_security(struct inode *inode, struct inode *dir, 120 const struct qstr *qstr); 121 #else 122 static inline int ext2_init_security(struct inode *inode, struct inode *dir, 123 const struct qstr *qstr) 124 { 125 return 0; 126 } 127 #endif 128