1 /* 2 File: linux/ext2_ext_attr.h 3 4 On-disk format of extended attributes for the ext2 filesystem. 5 6 (C) 2000 Andreas Gruenbacher, <a.gruenbacher (at) computer.org> 7 */ 8 9 #ifndef _EXT2_EXT_ATTR_H 10 #define _EXT2_EXT_ATTR_H 11 /* Magic value in attribute blocks */ 12 #define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000 13 #define EXT2_EXT_ATTR_MAGIC 0xEA020000 14 15 /* Maximum number of references to one attribute block */ 16 #define EXT2_EXT_ATTR_REFCOUNT_MAX 1024 17 18 struct ext2_ext_attr_header { 19 __u32 h_magic; /* magic number for identification */ 20 __u32 h_refcount; /* reference count */ 21 __u32 h_blocks; /* number of disk blocks used */ 22 __u32 h_hash; /* hash value of all attributes */ 23 __u32 h_checksum; /* crc32c(uuid+id+xattrs) */ 24 /* id = inum if refcount = 1, else blknum */ 25 __u32 h_reserved[3]; /* zero right now */ 26 }; 27 28 struct ext2_ext_attr_entry { 29 __u8 e_name_len; /* length of name */ 30 __u8 e_name_index; /* attribute name index */ 31 __u16 e_value_offs; /* offset in disk block of value */ 32 __u32 e_value_block; /* disk block attribute is stored on (n/i) */ 33 __u32 e_value_size; /* size of attribute value */ 34 __u32 e_hash; /* hash value of name and value */ 35 #if 0 36 char e_name[0]; /* attribute name */ 37 #endif 38 }; 39 40 #define EXT2_EXT_ATTR_PAD_BITS 2 41 #define EXT2_EXT_ATTR_PAD ((unsigned) 1<<EXT2_EXT_ATTR_PAD_BITS) 42 #define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1) 43 #define EXT2_EXT_ATTR_LEN(name_len) \ 44 (((name_len) + EXT2_EXT_ATTR_ROUND + \ 45 sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND) 46 #define EXT2_EXT_ATTR_NEXT(entry) \ 47 ( (struct ext2_ext_attr_entry *)( \ 48 (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) ) 49 #define EXT2_EXT_ATTR_SIZE(size) \ 50 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND) 51 #define EXT2_EXT_IS_LAST_ENTRY(entry) (*((__u32 *)(entry)) == 0UL) 52 #define EXT2_EXT_ATTR_NAME(entry) \ 53 (((char *) (entry)) + sizeof(struct ext2_ext_attr_entry)) 54 #define EXT2_XATTR_LEN(name_len) \ 55 (((name_len) + EXT2_EXT_ATTR_ROUND + \ 56 sizeof(struct ext2_xattr_entry)) & ~EXT2_EXT_ATTR_ROUND) 57 #define EXT2_XATTR_SIZE(size) \ 58 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND) 59 60 #ifdef __KERNEL__ 61 # ifdef CONFIG_EXT2_FS_EXT_ATTR 62 extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int); 63 extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int); 64 extern void ext2_ext_attr_free_inode(struct inode *inode); 65 extern void ext2_ext_attr_put_super(struct super_block *sb); 66 extern int ext2_ext_attr_init(void); 67 extern void ext2_ext_attr_done(void); 68 # else 69 # define ext2_get_ext_attr NULL 70 # define ext2_set_ext_attr NULL 71 # endif 72 #endif /* __KERNEL__ */ 73 #endif /* _EXT2_EXT_ATTR_H */ 74
