ext2_ext_attr.h revision 0d63467ddb76ef0c08481b74dae1fc7d6f364d1d
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@computer.org> 7*/ 8 9/* Magic value in attribute blocks */ 10#define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000 11#define EXT2_EXT_ATTR_MAGIC 0xEA020000 12 13/* Maximum number of references to one attribute block */ 14#define EXT2_EXT_ATTR_REFCOUNT_MAX 1024 15 16struct ext2_ext_attr_header { 17 __u32 h_magic; /* magic number for identification */ 18 __u32 h_refcount; /* reference count */ 19 __u32 h_blocks; /* number of disk blocks used */ 20 __u32 h_hash; /* hash value of all attributes */ 21 __u32 h_reserved[4]; /* zero right now */ 22}; 23 24struct ext2_ext_attr_entry { 25 __u8 e_name_len; /* length of name */ 26 __u8 e_name_index; /* attribute name index */ 27 __u16 e_value_offs; /* offset in disk block of value */ 28 __u32 e_value_block; /* disk block attribute is stored on (n/i) */ 29 __u32 e_value_size; /* size of attribute value */ 30 __u32 e_hash; /* hash value of name and value */ 31 char e_name[0]; /* attribute name */ 32}; 33 34#define EXT2_EXT_ATTR_PAD_BITS 2 35#define EXT2_EXT_ATTR_PAD (1<<EXT2_EXT_ATTR_PAD_BITS) 36#define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1) 37#define EXT2_EXT_ATTR_LEN(name_len) \ 38 (((name_len) + EXT2_EXT_ATTR_ROUND + \ 39 sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND) 40#define EXT2_EXT_ATTR_NEXT(entry) \ 41 ( (struct ext2_ext_attr_entry *)( \ 42 (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) ) 43#define EXT2_EXT_ATTR_SIZE(size) \ 44 (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND) 45 46#ifdef __KERNEL__ 47# ifdef CONFIG_EXT2_FS_EXT_ATTR 48extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int); 49extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int); 50extern void ext2_ext_attr_free_inode(struct inode *inode); 51extern void ext2_ext_attr_put_super(struct super_block *sb); 52extern int ext2_ext_attr_init(void); 53extern void ext2_ext_attr_done(void); 54# else 55# define ext2_get_ext_attr NULL 56# define ext2_set_ext_attr NULL 57# endif 58#endif /* __KERNEL__ */ 59 60