diff options
Diffstat (limited to 'lib/ext2fs/ext2_ext_attr.h')
| -rw-r--r-- | lib/ext2fs/ext2_ext_attr.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/lib/ext2fs/ext2_ext_attr.h b/lib/ext2fs/ext2_ext_attr.h new file mode 100644 index 0000000..c6068c4 --- /dev/null +++ b/lib/ext2fs/ext2_ext_attr.h @@ -0,0 +1,84 @@ +/* + File: linux/ext2_ext_attr.h + + On-disk format of extended attributes for the ext2 filesystem. + + (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org> +*/ + +#ifndef _EXT2_EXT_ATTR_H +#define _EXT2_EXT_ATTR_H +/* Magic value in attribute blocks */ +#define EXT2_EXT_ATTR_MAGIC_v1 0xEA010000 +#define EXT2_EXT_ATTR_MAGIC 0xEA020000 + +/* Maximum number of references to one attribute block */ +#define EXT2_EXT_ATTR_REFCOUNT_MAX 1024 + +struct ext2_ext_attr_header { + __u32 h_magic; /* magic number for identification */ + __u32 h_refcount; /* reference count */ + __u32 h_blocks; /* number of disk blocks used */ + __u32 h_hash; /* hash value of all attributes */ + __u32 h_checksum; /* crc32c(uuid+id+xattrs) */ + /* id = inum if refcount = 1, else blknum */ + __u32 h_reserved[3]; /* zero right now */ +}; + +struct ext2_ext_attr_entry { + __u8 e_name_len; /* length of name */ + __u8 e_name_index; /* attribute name index */ + __u16 e_value_offs; /* offset in disk block of value */ + __u32 e_value_inum; /* inode in which the value is stored */ + __u32 e_value_size; /* size of attribute value */ + __u32 e_hash; /* hash value of name and value */ +#if 0 + char e_name[0]; /* attribute name */ +#endif +}; + +#define EXT2_EXT_ATTR_PAD_BITS 2 +#define EXT2_EXT_ATTR_PAD ((unsigned) 1<<EXT2_EXT_ATTR_PAD_BITS) +#define EXT2_EXT_ATTR_ROUND (EXT2_EXT_ATTR_PAD-1) +#define EXT2_EXT_ATTR_LEN(name_len) \ + (((name_len) + EXT2_EXT_ATTR_ROUND + \ + sizeof(struct ext2_ext_attr_entry)) & ~EXT2_EXT_ATTR_ROUND) +#define EXT2_EXT_ATTR_NEXT(entry) \ + ( (struct ext2_ext_attr_entry *)( \ + (char *)(entry) + EXT2_EXT_ATTR_LEN((entry)->e_name_len)) ) +#define EXT2_EXT_ATTR_SIZE(size) \ + (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND) +#define EXT2_EXT_IS_LAST_ENTRY(entry) (*((__u32 *)(entry)) == 0UL) +#define EXT2_EXT_ATTR_NAME(entry) \ + (((char *) (entry)) + sizeof(struct ext2_ext_attr_entry)) +#define EXT2_XATTR_LEN(name_len) \ + (((name_len) + EXT2_EXT_ATTR_ROUND + \ + sizeof(struct ext2_xattr_entry)) & ~EXT2_EXT_ATTR_ROUND) +#define EXT2_XATTR_SIZE(size) \ + (((size) + EXT2_EXT_ATTR_ROUND) & ~EXT2_EXT_ATTR_ROUND) + +/* + * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking + * for file system consistency errors, we use a somewhat bigger value. + * This allows XATTR_SIZE_MAX to grow in the future, but by using this + * instead of INT_MAX for certain consistency checks, we don't need to + * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is + * defined in include/uapi/linux/limits.h, so changing it is going + * not going to be trivial....) + */ +#define EXT2_XATTR_SIZE_MAX (1 << 24) + +#ifdef __KERNEL__ +# ifdef CONFIG_EXT2_FS_EXT_ATTR +extern int ext2_get_ext_attr(struct inode *, const char *, char *, size_t, int); +extern int ext2_set_ext_attr(struct inode *, const char *, char *, size_t, int); +extern void ext2_ext_attr_free_inode(struct inode *inode); +extern void ext2_ext_attr_put_super(struct super_block *sb); +extern int ext2_ext_attr_init(void); +extern void ext2_ext_attr_done(void); +# else +# define ext2_get_ext_attr NULL +# define ext2_set_ext_attr NULL +# endif +#endif /* __KERNEL__ */ +#endif /* _EXT2_EXT_ATTR_H */ |