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1 /*
2 * Copyright (c) 2000,2002-2003,2005 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_H__
19 #define __XFS_ATTR_H__
20
21 struct xfs_inode;
22 struct xfs_da_args;
23 struct xfs_attr_list_context;
24
25 /*
26 * Large attribute lists are structured around Btrees where all the data
27 * elements are in the leaf nodes. Attribute names are hashed into an int,
28 * then that int is used as the index into the Btree. Since the hashval
29 * of an attribute name may not be unique, we may have duplicate keys.
30 * The internal links in the Btree are logical block offsets into the file.
31 *
32 * Small attribute lists use a different format and are packed as tightly
33 * as possible so as to fit into the literal area of the inode.
34 */
35
36 /*========================================================================
37 * External interfaces
38 *========================================================================*/
39
40
41 #define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */
42 #define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */
43 #define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */
44 #define ATTR_SECURE 0x0008 /* use attrs in security namespace */
45 #define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */
46 #define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */
47
48 #define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
49 #define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
50
51 /*
52 * The maximum size (into the kernel or returned from the kernel) of an
53 * attribute value or the buffer used for an attr_list() call. Larger
54 * sizes will result in an ERANGE return code.
55 */
56 #define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */
57
58 /*
59 * Define how lists of attribute names are returned to the user from
60 * the attr_list() call. A large, 32bit aligned, buffer is passed in
61 * along with its size. We put an array of offsets at the top that each
62 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
63 */
64 typedef struct attrlist {
65 __s32 al_count; /* number of entries in attrlist */
66 __s32 al_more; /* T/F: more attrs (do call again) */
67 __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */
68 } attrlist_t;
69
70 /*
71 * Show the interesting info about one attribute. This is what the
72 * al_offset[i] entry points to.
73 */
74 typedef struct attrlist_ent { /* data from attr_list() */
75 __u32 a_valuelen; /* number bytes in value of attr */
76 char a_name[1]; /* attr name (NULL terminated) */
77 } attrlist_ent_t;
78
79 /*
80 * Given a pointer to the (char*) buffer containing the attr_list() result,
81 * and an index, return a pointer to the indicated attribute in the buffer.
82 */
83 #define ATTR_ENTRY(buffer, index) \
84 ((attrlist_ent_t *) \
85 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
86
87 /*
88 * Kernel-internal version of the attrlist cursor.
89 */
90 typedef struct attrlist_cursor_kern {
91 __u32 hashval; /* hash value of next entry to add */
92 __u32 blkno; /* block containing entry (suggestion) */
93 __u32 offset; /* offset in list of equal-hashvals */
94 __u16 pad1; /* padding to match user-level */
95 __u8 pad2; /* padding to match user-level */
96 __u8 initted; /* T/F: cursor has been initialized */
97 } attrlist_cursor_kern_t;
98
99
100 /*========================================================================
101 * Structure used to pass context around among the routines.
102 *========================================================================*/
103
104
105 typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int,
106 char *, int, int, char *);
107
108 typedef struct xfs_attr_list_context {
109 struct xfs_inode *dp; /* inode */
110 struct attrlist_cursor_kern *cursor; /* position in list */
111 char *alist; /* output buffer */
112 int seen_enough; /* T/F: seen enough of list? */
113 ssize_t count; /* num used entries */
114 int dupcnt; /* count dup hashvals seen */
115 int bufsize; /* total buffer size */
116 int firstu; /* first used byte in buffer */
117 int flags; /* from VOP call */
118 int resynch; /* T/F: resynch with cursor */
119 int put_value; /* T/F: need value for listent */
120 put_listent_func_t put_listent; /* list output fmt function */
121 int index; /* index into output buffer */
122 } xfs_attr_list_context_t;
123
124
125 /*========================================================================
126 * Function prototypes for the kernel.
127 *========================================================================*/
128
129 /*
130 * Overall external interface routines.
131 */
132 int xfs_attr_calc_size(struct xfs_inode *, int, int, int *);
133 int xfs_attr_inactive(struct xfs_inode *dp);
134 int xfs_attr_fetch(struct xfs_inode *, struct xfs_name *, char *, int *, int);
135 int xfs_attr_rmtval_get(struct xfs_da_args *args);
136 int xfs_attr_list_int(struct xfs_attr_list_context *);
137
138 #endif /* __XFS_ATTR_H__ */