Loading...
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);
}
|