1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
/*
* Source file used to associate/disassociate behaviors with virtualized
* objects. See xfs_behavior.h for more information about behaviors, etc.
*
* The implementation is split between functions in this file and macros
* in xfs_behavior.h.
*/
/*
* Insert a new behavior descriptor into a behavior chain.
*
* The behavior chain is ordered based on the 'position' number which
* lives in the first field of the ops vector (higher numbers first).
*
* Attempts to insert duplicate ops result in an EINVAL return code.
* Otherwise, return 0 to indicate success.
*/
int
bhv_insert(bhv_head_t *bhp, bhv_desc_t *bdp)
{
bhv_desc_t *curdesc, *prev;
int position;
/*
* Validate the position value of the new behavior.
*/
position = BHV_POSITION(bdp);
ASSERT(position >= BHV_POSITION_BASE && position <= BHV_POSITION_TOP);
/*
* Find location to insert behavior. Check for duplicates.
*/
prev = NULL;
for (curdesc = bhp->bh_first;
curdesc != NULL;
curdesc = curdesc->bd_next) {
/* Check for duplication. */
if (curdesc->bd_ops == bdp->bd_ops) {
ASSERT(0);
return EINVAL;
}
/* Find correct position */
if (position >= BHV_POSITION(curdesc)) {
ASSERT(position != BHV_POSITION(curdesc));
break; /* found it */
}
prev = curdesc;
}
if (prev == NULL) {
/* insert at front of chain */
bdp->bd_next = bhp->bh_first;
bhp->bh_first = bdp;
} else {
/* insert after prev */
bdp->bd_next = prev->bd_next;
prev->bd_next = bdp;
}
return 0;
}
/*
* Remove a behavior descriptor from a position in a behavior chain;
* the position is guaranteed not to be the first position.
* Should only be called by the bhv_remove() macro.
*/
void
bhv_remove_not_first(bhv_head_t *bhp, bhv_desc_t *bdp)
{
bhv_desc_t *curdesc, *prev;
ASSERT(bhp->bh_first != NULL);
ASSERT(bhp->bh_first->bd_next != NULL);
prev = bhp->bh_first;
for (curdesc = bhp->bh_first->bd_next;
curdesc != NULL;
curdesc = curdesc->bd_next) {
if (curdesc == bdp)
break; /* found it */
prev = curdesc;
}
ASSERT(curdesc == bdp);
prev->bd_next = bdp->bd_next; /* remove from after prev */
}
/*
* Looks for the first behavior within a specified range of positions.
* Return the associated behavior descriptor. Or NULL, if none found.
*/
bhv_desc_t *
bhv_lookup_range(bhv_head_t *bhp, int low, int high)
{
bhv_desc_t *curdesc;
for (curdesc = bhp->bh_first;
curdesc != NULL;
curdesc = curdesc->bd_next) {
int position = BHV_POSITION(curdesc);
if (position <= high) {
if (position >= low)
return curdesc;
return NULL;
}
}
return NULL;
}
/*
* Return the base behavior in the chain, or NULL if the chain
* is empty.
*
* The caller has not read locked the behavior chain, so acquire the
* lock before traversing the chain.
*/
bhv_desc_t *
bhv_base(bhv_head_t *bhp)
{
bhv_desc_t *curdesc;
for (curdesc = bhp->bh_first;
curdesc != NULL;
curdesc = curdesc->bd_next) {
if (curdesc->bd_next == NULL) {
return curdesc;
}
}
return NULL;
}
void
bhv_head_init(
bhv_head_t *bhp,
char *name)
{
bhp->bh_first = NULL;
}
void
bhv_insert_initial(
bhv_head_t *bhp,
bhv_desc_t *bdp)
{
ASSERT(bhp->bh_first == NULL);
(bhp)->bh_first = bdp;
}
void
bhv_head_destroy(
bhv_head_t *bhp)
{
ASSERT(bhp->bh_first == NULL);
}
|
