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 #define EXT4_XATTR_INDEX_SYSTEM 7 25 #define EXT4_XATTR_INDEX_RICHACL 8 26 27 struct ext4_xattr_header { 28 __le32 h_magic; /* magic number for identification */ 29 __le32 h_refcount; /* reference count */ 30 __le32 h_blocks; /* number of disk blocks used */ 31 __le32 h_hash; /* hash value of all attributes */ 32 __le32 h_checksum; /* crc32c(uuid+id+xattrblock) */ 33 /* id = inum if refcount=1, blknum otherwise */ 34 __u32 h_reserved[3]; /* zero right now */ 35 }; 36 37 struct ext4_xattr_ibody_header { 38 __le32 h_magic; /* magic number for identification */ 39 }; 40 41 struct ext4_xattr_entry { 42 __u8 e_name_len; /* length of name */ 43 __u8 e_name_index; /* attribute name index */ 44 __le16 e_value_offs; /* offset in disk block of value */ 45 __le32 e_value_block; /* disk block attribute is stored on (n/i) */ 46 __le32 e_value_size; /* size of attribute value */ 47 __le32 e_hash; /* hash value of name and value */ 48 char e_name[0]; /* attribute name */ 49 }; 50 51 #define EXT4_XATTR_PAD_BITS 2 52 #define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS) 53 #define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1) 54 #define EXT4_XATTR_LEN(name_len) \ 55 (((name_len) + EXT4_XATTR_ROUND + \ 56 sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND) 57 #define EXT4_XATTR_NEXT(entry) \ 58 ((struct ext4_xattr_entry *)( \ 59 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len))) 60 #define EXT4_XATTR_SIZE(size) \ 61 (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND) 62 63 #define IHDR(inode, raw_inode) \ 64 ((struct ext4_xattr_ibody_header *) \ 65 ((void *)raw_inode + \ 66 EXT4_GOOD_OLD_INODE_SIZE + \ 67 EXT4_I(inode)->i_extra_isize)) 68 #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) 69 70 #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) 71 #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) 72 #define BFIRST(bh) ENTRY(BHDR(bh)+1) 73 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) 74 75 #define EXT4_ZERO_XATTR_VALUE ((void *)-1) 76 77 struct ext4_xattr_info { 78 int name_index; 79 const char *name; 80 const void *value; 81 size_t value_len; 82 }; 83 84 struct ext4_xattr_search { 85 struct ext4_xattr_entry *first; 86 void *base; 87 void *end; 88 struct ext4_xattr_entry *here; 89 int not_found; 90 }; 91 92 struct ext4_xattr_ibody_find { 93 struct ext4_xattr_search s; 94 struct ext4_iloc iloc; 95 }; 96 97 extern const struct xattr_handler ext4_xattr_user_handler; 98 extern const struct xattr_handler ext4_xattr_trusted_handler; 99 extern const struct xattr_handler ext4_xattr_security_handler; 100 101 extern ssize_t ext4_listxattr(struct dentry *, char *, size_t); 102 103 extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t); 104 extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int); 105 extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int); 106 107 extern void ext4_xattr_delete_inode(handle_t *, struct inode *); 108 extern void ext4_xattr_put_super(struct super_block *); 109 110 extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, 111 struct ext4_inode *raw_inode, handle_t *handle); 112 113 extern const struct xattr_handler *ext4_xattr_handlers[]; 114 115 extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, 116 struct ext4_xattr_ibody_find *is); 117 extern int ext4_xattr_ibody_get(struct inode *inode, int name_index, 118 const char *name, 119 void *buffer, size_t buffer_size); 120 extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, 121 struct ext4_xattr_info *i, 122 struct ext4_xattr_ibody_find *is); 123 124 extern struct mb_cache *ext4_xattr_create_cache(char *name); 125 extern void ext4_xattr_destroy_cache(struct mb_cache *); 126 127 #ifdef CONFIG_EXT4_FS_SECURITY 128 extern int ext4_init_security(handle_t *handle, struct inode *inode, 129 struct inode *dir, const struct qstr *qstr); 130 #else 131 static inline int ext4_init_security(handle_t *handle, struct inode *inode, 132 struct inode *dir, const struct qstr *qstr) 133 { 134 return 0; 135 } 136 #endif 137