xref: /linux/fs/xfs/libxfs/xfs_attr_sf.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #ifndef __XFS_ATTR_SF_H__
19 #define	__XFS_ATTR_SF_H__
20 
21 /*
22  * Attribute storage when stored inside the inode.
23  *
24  * Small attribute lists are packed as tightly as possible so as
25  * to fit into the literal area of the inode.
26  */
27 
28 /*
29  * Entries are packed toward the top as tight as possible.
30  */
31 typedef struct xfs_attr_shortform {
32 	struct xfs_attr_sf_hdr {	/* constant-structure header block */
33 		__be16	totsize;	/* total bytes in shortform list */
34 		__u8	count;	/* count of active entries */
35 	} hdr;
36 	struct xfs_attr_sf_entry {
37 		__uint8_t namelen;	/* actual length of name (no NULL) */
38 		__uint8_t valuelen;	/* actual length of value (no NULL) */
39 		__uint8_t flags;	/* flags bits (see xfs_attr_leaf.h) */
40 		__uint8_t nameval[1];	/* name & value bytes concatenated */
41 	} list[1];			/* variable sized array */
42 } xfs_attr_shortform_t;
43 typedef struct xfs_attr_sf_hdr xfs_attr_sf_hdr_t;
44 typedef struct xfs_attr_sf_entry xfs_attr_sf_entry_t;
45 
46 /*
47  * We generate this then sort it, attr_list() must return things in hash-order.
48  */
49 typedef struct xfs_attr_sf_sort {
50 	__uint8_t	entno;		/* entry number in original list */
51 	__uint8_t	namelen;	/* length of name value (no null) */
52 	__uint8_t	valuelen;	/* length of value */
53 	__uint8_t	flags;		/* flags bits (see xfs_attr_leaf.h) */
54 	xfs_dahash_t	hash;		/* this entry's hash value */
55 	unsigned char	*name;		/* name value, pointer into buffer */
56 } xfs_attr_sf_sort_t;
57 
58 #define XFS_ATTR_SF_ENTSIZE_BYNAME(nlen,vlen)	/* space name/value uses */ \
59 	(((int)sizeof(xfs_attr_sf_entry_t)-1 + (nlen)+(vlen)))
60 #define XFS_ATTR_SF_ENTSIZE_MAX			/* max space for name&value */ \
61 	((1 << (NBBY*(int)sizeof(__uint8_t))) - 1)
62 #define XFS_ATTR_SF_ENTSIZE(sfep)		/* space an entry uses */ \
63 	((int)sizeof(xfs_attr_sf_entry_t)-1 + (sfep)->namelen+(sfep)->valuelen)
64 #define XFS_ATTR_SF_NEXTENTRY(sfep)		/* next entry in struct */ \
65 	((xfs_attr_sf_entry_t *)((char *)(sfep) + XFS_ATTR_SF_ENTSIZE(sfep)))
66 #define XFS_ATTR_SF_TOTSIZE(dp)			/* total space in use */ \
67 	(be16_to_cpu(((xfs_attr_shortform_t *)	\
68 		((dp)->i_afp->if_u1.if_data))->hdr.totsize))
69 
70 #endif	/* __XFS_ATTR_SF_H__ */
71