[linux-2.6-block.git] / fs / ext4 / xattr.h

/*
  File: fs/ext4/xattr.h

  On-disk format of extended attributes for the ext4 filesystem.

  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/

#include <linux/xattr.h>

/* Magic value in attribute blocks */
#define EXT4_XATTR_MAGIC		0xEA020000

/* Maximum number of references to one attribute block */
#define EXT4_XATTR_REFCOUNT_MAX		1024

/* Name indexes */
#define EXT4_XATTR_INDEX_USER			1
#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS	2
#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT	3
#define EXT4_XATTR_INDEX_TRUSTED		4
#define	EXT4_XATTR_INDEX_LUSTRE			5
#define EXT4_XATTR_INDEX_SECURITY	        6
#define EXT4_XATTR_INDEX_SYSTEM			7
#define EXT4_XATTR_INDEX_RICHACL		8
#define EXT4_XATTR_INDEX_ENCRYPTION		9

struct ext4_xattr_header {
	__le32	h_magic;	/* magic number for identification */
	__le32	h_refcount;	/* reference count */
	__le32	h_blocks;	/* number of disk blocks used */
	__le32	h_hash;		/* hash value of all attributes */
	__le32	h_checksum;	/* crc32c(uuid+id+xattrblock) */
				/* id = inum if refcount=1, blknum otherwise */
	__u32	h_reserved[3];	/* zero right now */
};

struct ext4_xattr_ibody_header {
	__le32	h_magic;	/* magic number for identification */
};

struct ext4_xattr_entry {
	__u8	e_name_len;	/* length of name */
	__u8	e_name_index;	/* attribute name index */
	__le16	e_value_offs;	/* offset in disk block of value */
	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
	__le32	e_value_size;	/* size of attribute value */
	__le32	e_hash;		/* hash value of name and value */
	char	e_name[0];	/* attribute name */
};

#define EXT4_XATTR_PAD_BITS		2
#define EXT4_XATTR_PAD		(1<<EXT4_XATTR_PAD_BITS)
#define EXT4_XATTR_ROUND		(EXT4_XATTR_PAD-1)
#define EXT4_XATTR_LEN(name_len) \
	(((name_len) + EXT4_XATTR_ROUND + \
	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
#define EXT4_XATTR_NEXT(entry) \
	((struct ext4_xattr_entry *)( \
	 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
#define EXT4_XATTR_SIZE(size) \
	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)

#define IHDR(inode, raw_inode) \
	((struct ext4_xattr_ibody_header *) \
		((void *)raw_inode + \
		EXT4_GOOD_OLD_INODE_SIZE + \
		EXT4_I(inode)->i_extra_isize))
#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))

#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
#define BFIRST(bh) ENTRY(BHDR(bh)+1)
#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)

#define EXT4_ZERO_XATTR_VALUE ((void *)-1)

struct ext4_xattr_info {
	int name_index;
	const char *name;
	const void *value;
	size_t value_len;
};

struct ext4_xattr_search {
	struct ext4_xattr_entry *first;
	void *base;
	void *end;
	struct ext4_xattr_entry *here;
	int not_found;
};

struct ext4_xattr_ibody_find {
	struct ext4_xattr_search s;
	struct ext4_iloc iloc;
};

extern const struct xattr_handler ext4_xattr_user_handler;
extern const struct xattr_handler ext4_xattr_trusted_handler;
extern const struct xattr_handler ext4_xattr_security_handler;

#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"

extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);

extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);

extern void ext4_xattr_delete_inode(handle_t *, struct inode *);

extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
			    struct ext4_inode *raw_inode, handle_t *handle);

extern const struct xattr_handler *ext4_xattr_handlers[];

extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
				 struct ext4_xattr_ibody_find *is);
extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
				const char *name,
				void *buffer, size_t buffer_size);
extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
				       struct ext4_xattr_info *i,
				       struct ext4_xattr_ibody_find *is);

extern struct mb_cache *ext4_xattr_create_cache(void);
extern void ext4_xattr_destroy_cache(struct mb_cache *);

#ifdef CONFIG_EXT4_FS_SECURITY
extern int ext4_init_security(handle_t *handle, struct inode *inode,
			      struct inode *dir, const struct qstr *qstr);
#else
static inline int ext4_init_security(handle_t *handle, struct inode *inode,
				     struct inode *dir, const struct qstr *qstr)
{
	return 0;
}
#endif
Commit	Line	Data
ac27a0ec	1	/*
617ba13b	2	File: fs/ext4/xattr.h
ac27a0ec	3
617ba13b	4	On-disk format of extended attributes for the ext4 filesystem.
ac27a0ec DK	5
	6	(C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
	7	*/
	8
	9	#include <linux/xattr.h>
	10
	11	/* Magic value in attribute blocks */
617ba13b	12	#define EXT4_XATTR_MAGIC 0xEA020000
ac27a0ec DK	13
ac27a0ec DK	14	/* Maximum number of references to one attribute block */
617ba13b	15	#define EXT4_XATTR_REFCOUNT_MAX 1024
ac27a0ec DK	16
ac27a0ec DK	17	/* Name indexes */
617ba13b MC	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
67cf5b09	24	#define EXT4_XATTR_INDEX_SYSTEM 7
fd03d8da	25	#define EXT4_XATTR_INDEX_RICHACL 8
887e2c45	26	#define EXT4_XATTR_INDEX_ENCRYPTION 9
617ba13b MC	27
617ba13b MC	28	struct ext4_xattr_header {
ac27a0ec DK	29	__le32 h_magic; /* magic number for identification */
	30	__le32 h_refcount; /* reference count */
	31	__le32 h_blocks; /* number of disk blocks used */
	32	__le32 h_hash; /* hash value of all attributes */
e6153918 DW	33	__le32 h_checksum; /* crc32c(uuid+id+xattrblock) */
	34	/* id = inum if refcount=1, blknum otherwise */
	35	__u32 h_reserved[3]; /* zero right now */
ac27a0ec DK	36	};
ac27a0ec DK	37
617ba13b	38	struct ext4_xattr_ibody_header {
ac27a0ec DK	39	__le32 h_magic; /* magic number for identification */
	40	};
	41
617ba13b	42	struct ext4_xattr_entry {
ac27a0ec DK	43	__u8 e_name_len; /* length of name */
	44	__u8 e_name_index; /* attribute name index */
	45	__le16 e_value_offs; /* offset in disk block of value */
	46	__le32 e_value_block; /* disk block attribute is stored on (n/i) */
	47	__le32 e_value_size; /* size of attribute value */
	48	__le32 e_hash; /* hash value of name and value */
	49	char e_name[0]; /* attribute name */
	50	};
	51
617ba13b MC	52	#define EXT4_XATTR_PAD_BITS 2
	53	#define EXT4_XATTR_PAD (1<<EXT4_XATTR_PAD_BITS)
	54	#define EXT4_XATTR_ROUND (EXT4_XATTR_PAD-1)
	55	#define EXT4_XATTR_LEN(name_len) \
	56	(((name_len) + EXT4_XATTR_ROUND + \
	57	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
	58	#define EXT4_XATTR_NEXT(entry) \
af5bc92d TT	59	((struct ext4_xattr_entry *)( \
af5bc92d TT	60	(char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
617ba13b MC	61	#define EXT4_XATTR_SIZE(size) \
617ba13b MC	62	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
ac27a0ec	63
6dd4ee7c KS	64	#define IHDR(inode, raw_inode) \
	65	((struct ext4_xattr_ibody_header *) \
	66	((void *)raw_inode + \
	67	EXT4_GOOD_OLD_INODE_SIZE + \
	68	EXT4_I(inode)->i_extra_isize))
	69	#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
	70
879b3825 TM	71	#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
	72	#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
	73	#define BFIRST(bh) ENTRY(BHDR(bh)+1)
	74	#define IS_LAST_ENTRY(entry) ((__u32 )(entry) == 0)
	75
bd9926e8	76	#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
879b3825 TM	77
	78	struct ext4_xattr_info {
	79	int name_index;
	80	const char *name;
	81	const void *value;
	82	size_t value_len;
	83	};
	84
	85	struct ext4_xattr_search {
	86	struct ext4_xattr_entry *first;
	87	void *base;
	88	void *end;
	89	struct ext4_xattr_entry *here;
	90	int not_found;
	91	};
	92
	93	struct ext4_xattr_ibody_find {
	94	struct ext4_xattr_search s;
	95	struct ext4_iloc iloc;
	96	};
	97
11e27528 SH	98	extern const struct xattr_handler ext4_xattr_user_handler;
11e27528 SH	99	extern const struct xattr_handler ext4_xattr_trusted_handler;
11e27528	100	extern const struct xattr_handler ext4_xattr_security_handler;
ac27a0ec	101
887e2c45 MH	102	#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
887e2c45 MH	103
617ba13b	104	extern ssize_t ext4_listxattr(struct dentry , char , size_t);
ac27a0ec	105
617ba13b	106	extern int ext4_xattr_get(struct inode , int, const char , void *, size_t);
617ba13b MC	107	extern int ext4_xattr_set(struct inode , int, const char , const void *, size_t, int);
617ba13b MC	108	extern int ext4_xattr_set_handle(handle_t , struct inode , int, const char , const void , size_t, int);
ac27a0ec	109
617ba13b	110	extern void ext4_xattr_delete_inode(handle_t , struct inode );
ac27a0ec	111
6dd4ee7c KS	112	extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
	113	struct ext4_inode raw_inode, handle_t handle);
	114
11e27528	115	extern const struct xattr_handler *ext4_xattr_handlers[];
ac27a0ec	116
879b3825 TM	117	extern int ext4_xattr_ibody_find(struct inode inode, struct ext4_xattr_info i,
	118	struct ext4_xattr_ibody_find *is);
	119	extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
	120	const char *name,
	121	void *buffer, size_t buffer_size);
0d812f77 TM	122	extern int ext4_xattr_ibody_inline_set(handle_t handle, struct inode inode,
	123	struct ext4_xattr_info *i,
	124	struct ext4_xattr_ibody_find *is);
879b3825	125
7a2508e1 JK	126	extern struct mb_cache *ext4_xattr_create_cache(void);
7a2508e1 JK	127	extern void ext4_xattr_destroy_cache(struct mb_cache *);
9c191f70	128
03010a33	129	#ifdef CONFIG_EXT4_FS_SECURITY
617ba13b	130	extern int ext4_init_security(handle_t handle, struct inode inode,
2a7dba39	131	struct inode dir, const struct qstr qstr);
ac27a0ec	132	#else
617ba13b	133	static inline int ext4_init_security(handle_t handle, struct inode inode,
2a7dba39	134	struct inode dir, const struct qstr qstr)
ac27a0ec DK	135	{
	136	return 0;
	137	}
	138	#endif