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 25struct 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 33struct ext4_xattr_ibody_header { 34 __le32 h_magic; /* magic number for identification */ 35}; 36 37struct 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 68extern const struct xattr_handler ext4_xattr_user_handler; 69extern const struct xattr_handler ext4_xattr_trusted_handler; 70extern const struct xattr_handler ext4_xattr_acl_access_handler; 71extern const struct xattr_handler ext4_xattr_acl_default_handler; 72extern const struct xattr_handler ext4_xattr_security_handler; 73 74extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 75 76extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 77extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 78extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 79 80extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 81extern void ext4_xattr_put_super(struct super_block *); 82 83extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 84 struct ext4_inode *raw_inode, handle_t *handle); 85 86extern int init_ext4_xattr(void); 87extern void exit_ext4_xattr(void); 88 89extern const struct xattr_handler *ext4_xattr_handlers[]; 90 91# else /* CONFIG_EXT4_FS_XATTR */ 92 93static inline int 94ext4_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 100static inline int 101ext4_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 107static inline int 108ext4_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 114static inline void 115ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) 116{ 117} 118 119static inline void 120ext4_xattr_put_super(struct super_block *sb) 121{ 122} 123 124static inline int 125init_ext4_xattr(void) 126{ 127 return 0; 128} 129 130static inline void 131exit_ext4_xattr(void) 132{ 133} 134 135static inline int 136ext4_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 147extern int ext4_init_security(handle_t *handle, struct inode *inode, 148 struct inode *dir); 149#else 150static inline int ext4_init_security(handle_t *handle, struct inode *inode, 151 struct inode *dir) 152{ 153 return 0; 154} 155#endif 156