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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
18#ifndef __XFS_ATTR_H__
19#define __XFS_ATTR_H__
20
Christoph Hellwigad9b4632008-06-23 13:23:48 +100021struct xfs_inode;
22struct xfs_da_args;
23struct xfs_attr_list_context;
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
49#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000051#define XFS_ATTR_FLAGS \
52 { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
53 { ATTR_ROOT, "ROOT" }, \
54 { ATTR_TRUST, "TRUST" }, \
55 { ATTR_SECURE, "SECURE" }, \
56 { ATTR_CREATE, "CREATE" }, \
57 { ATTR_REPLACE, "REPLACE" }, \
58 { ATTR_KERNOTIME, "KERNOTIME" }, \
59 { ATTR_KERNOVAL, "KERNOVAL" }
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061/*
62 * The maximum size (into the kernel or returned from the kernel) of an
63 * attribute value or the buffer used for an attr_list() call. Larger
64 * sizes will result in an ERANGE return code.
65 */
66#define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */
67
68/*
69 * Define how lists of attribute names are returned to the user from
70 * the attr_list() call. A large, 32bit aligned, buffer is passed in
71 * along with its size. We put an array of offsets at the top that each
72 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
73 */
74typedef struct attrlist {
75 __s32 al_count; /* number of entries in attrlist */
76 __s32 al_more; /* T/F: more attrs (do call again) */
77 __s32 al_offset[1]; /* byte offsets of attrs [var-sized] */
78} attrlist_t;
79
80/*
81 * Show the interesting info about one attribute. This is what the
82 * al_offset[i] entry points to.
83 */
84typedef struct attrlist_ent { /* data from attr_list() */
85 __u32 a_valuelen; /* number bytes in value of attr */
86 char a_name[1]; /* attr name (NULL terminated) */
87} attrlist_ent_t;
88
89/*
90 * Given a pointer to the (char*) buffer containing the attr_list() result,
91 * and an index, return a pointer to the indicated attribute in the buffer.
92 */
93#define ATTR_ENTRY(buffer, index) \
94 ((attrlist_ent_t *) \
95 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
96
97/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 * Kernel-internal version of the attrlist cursor.
99 */
100typedef struct attrlist_cursor_kern {
101 __u32 hashval; /* hash value of next entry to add */
102 __u32 blkno; /* block containing entry (suggestion) */
103 __u32 offset; /* offset in list of equal-hashvals */
104 __u16 pad1; /* padding to match user-level */
105 __u8 pad2; /* padding to match user-level */
106 __u8 initted; /* T/F: cursor has been initialized */
107} attrlist_cursor_kern_t;
108
109
110/*========================================================================
Christoph Hellwigad9b4632008-06-23 13:23:48 +1000111 * Structure used to pass context around among the routines.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 *========================================================================*/
113
Christoph Hellwigad9b4632008-06-23 13:23:48 +1000114
115typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int,
Dave Chinnera9273ca2010-01-20 10:47:48 +1100116 unsigned char *, int, int, unsigned char *);
Christoph Hellwigad9b4632008-06-23 13:23:48 +1000117
118typedef struct xfs_attr_list_context {
119 struct xfs_inode *dp; /* inode */
120 struct attrlist_cursor_kern *cursor; /* position in list */
121 char *alist; /* output buffer */
122 int seen_enough; /* T/F: seen enough of list? */
Tim Shimmin61f10fa2008-06-23 13:25:09 +1000123 ssize_t count; /* num used entries */
Christoph Hellwigad9b4632008-06-23 13:23:48 +1000124 int dupcnt; /* count dup hashvals seen */
125 int bufsize; /* total buffer size */
126 int firstu; /* first used byte in buffer */
127 int flags; /* from VOP call */
128 int resynch; /* T/F: resynch with cursor */
129 int put_value; /* T/F: need value for listent */
130 put_listent_func_t put_listent; /* list output fmt function */
131 int index; /* index into output buffer */
132} xfs_attr_list_context_t;
133
134
135/*========================================================================
136 * Function prototypes for the kernel.
137 *========================================================================*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
139/*
140 * Overall external interface routines.
141 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142int xfs_attr_inactive(struct xfs_inode *dp);
Christoph Hellwigad9b4632008-06-23 13:23:48 +1000143int xfs_attr_list_int(struct xfs_attr_list_context *);
Dave Chinnerabec5f22013-08-12 20:49:38 +1000144int xfs_inode_hasattr(struct xfs_inode *ip);
Dave Chinnerc24b5df2013-08-12 20:49:45 +1000145int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name,
146 unsigned char *value, int *valuelenp, int flags);
147int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
148 unsigned char *value, int valuelen, int flags);
149int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags);
150int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
151 int flags, struct attrlist_cursor_kern *cursor);
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
154#endif /* __XFS_ATTR_H__ */