1153323Srodrigc/* 2159451Srodrigc * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. 3159451Srodrigc * All Rights Reserved. 4153323Srodrigc * 5159451Srodrigc * This program is free software; you can redistribute it and/or 6159451Srodrigc * modify it under the terms of the GNU General Public License as 7153323Srodrigc * published by the Free Software Foundation. 8153323Srodrigc * 9159451Srodrigc * This program is distributed in the hope that it would be useful, 10159451Srodrigc * but WITHOUT ANY WARRANTY; without even the implied warranty of 11159451Srodrigc * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12159451Srodrigc * GNU General Public License for more details. 13153323Srodrigc * 14159451Srodrigc * You should have received a copy of the GNU General Public License 15159451Srodrigc * along with this program; if not, write the Free Software Foundation, 16159451Srodrigc * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17153323Srodrigc */ 18153323Srodrigc#include "xfs.h" 19153323Srodrigc 20153323Srodrigc/* 21153323Srodrigc * Source file used to associate/disassociate behaviors with virtualized 22153323Srodrigc * objects. See xfs_behavior.h for more information about behaviors, etc. 23153323Srodrigc * 24153323Srodrigc * The implementation is split between functions in this file and macros 25153323Srodrigc * in xfs_behavior.h. 26153323Srodrigc */ 27153323Srodrigc 28153323Srodrigc/* 29153323Srodrigc * Insert a new behavior descriptor into a behavior chain. 30153323Srodrigc * 31153323Srodrigc * The behavior chain is ordered based on the 'position' number which 32153323Srodrigc * lives in the first field of the ops vector (higher numbers first). 33153323Srodrigc * 34159451Srodrigc * Attempts to insert duplicate ops result in an EINVAL return code. 35153323Srodrigc * Otherwise, return 0 to indicate success. 36153323Srodrigc */ 37153323Srodrigcint 38153323Srodrigcbhv_insert(bhv_head_t *bhp, bhv_desc_t *bdp) 39153323Srodrigc{ 40153323Srodrigc bhv_desc_t *curdesc, *prev; 41153323Srodrigc int position; 42153323Srodrigc 43153323Srodrigc /* 44153323Srodrigc * Validate the position value of the new behavior. 45153323Srodrigc */ 46153323Srodrigc position = BHV_POSITION(bdp); 47153323Srodrigc ASSERT(position >= BHV_POSITION_BASE && position <= BHV_POSITION_TOP); 48153323Srodrigc 49153323Srodrigc /* 50153323Srodrigc * Find location to insert behavior. Check for duplicates. 51153323Srodrigc */ 52153323Srodrigc prev = NULL; 53153323Srodrigc for (curdesc = bhp->bh_first; 54153323Srodrigc curdesc != NULL; 55153323Srodrigc curdesc = curdesc->bd_next) { 56153323Srodrigc 57153323Srodrigc /* Check for duplication. */ 58153323Srodrigc if (curdesc->bd_ops == bdp->bd_ops) { 59153323Srodrigc ASSERT(0); 60153323Srodrigc return EINVAL; 61153323Srodrigc } 62153323Srodrigc 63153323Srodrigc /* Find correct position */ 64153323Srodrigc if (position >= BHV_POSITION(curdesc)) { 65153323Srodrigc ASSERT(position != BHV_POSITION(curdesc)); 66153323Srodrigc break; /* found it */ 67153323Srodrigc } 68153323Srodrigc 69153323Srodrigc prev = curdesc; 70153323Srodrigc } 71153323Srodrigc 72153323Srodrigc if (prev == NULL) { 73153323Srodrigc /* insert at front of chain */ 74153323Srodrigc bdp->bd_next = bhp->bh_first; 75153323Srodrigc bhp->bh_first = bdp; 76153323Srodrigc } else { 77153323Srodrigc /* insert after prev */ 78153323Srodrigc bdp->bd_next = prev->bd_next; 79153323Srodrigc prev->bd_next = bdp; 80153323Srodrigc } 81153323Srodrigc 82153323Srodrigc return 0; 83153323Srodrigc} 84153323Srodrigc 85153323Srodrigc/* 86153323Srodrigc * Remove a behavior descriptor from a position in a behavior chain; 87159451Srodrigc * the position is guaranteed not to be the first position. 88153323Srodrigc * Should only be called by the bhv_remove() macro. 89153323Srodrigc */ 90153323Srodrigcvoid 91153323Srodrigcbhv_remove_not_first(bhv_head_t *bhp, bhv_desc_t *bdp) 92153323Srodrigc{ 93153323Srodrigc bhv_desc_t *curdesc, *prev; 94153323Srodrigc 95153323Srodrigc ASSERT(bhp->bh_first != NULL); 96153323Srodrigc ASSERT(bhp->bh_first->bd_next != NULL); 97153323Srodrigc 98153323Srodrigc prev = bhp->bh_first; 99153323Srodrigc for (curdesc = bhp->bh_first->bd_next; 100153323Srodrigc curdesc != NULL; 101153323Srodrigc curdesc = curdesc->bd_next) { 102153323Srodrigc 103153323Srodrigc if (curdesc == bdp) 104153323Srodrigc break; /* found it */ 105153323Srodrigc prev = curdesc; 106153323Srodrigc } 107153323Srodrigc 108153323Srodrigc ASSERT(curdesc == bdp); 109153323Srodrigc prev->bd_next = bdp->bd_next; /* remove from after prev */ 110153323Srodrigc} 111153323Srodrigc 112153323Srodrigc/* 113153323Srodrigc * Look for a specific ops vector on the specified behavior chain. 114153323Srodrigc * Return the associated behavior descriptor. Or NULL, if not found. 115153323Srodrigc */ 116153323Srodrigcbhv_desc_t * 117153323Srodrigcbhv_lookup(bhv_head_t *bhp, void *ops) 118153323Srodrigc{ 119153323Srodrigc bhv_desc_t *curdesc; 120153323Srodrigc 121153323Srodrigc for (curdesc = bhp->bh_first; 122153323Srodrigc curdesc != NULL; 123153323Srodrigc curdesc = curdesc->bd_next) { 124153323Srodrigc 125153323Srodrigc if (curdesc->bd_ops == ops) 126153323Srodrigc return curdesc; 127153323Srodrigc } 128153323Srodrigc 129153323Srodrigc return NULL; 130153323Srodrigc} 131153323Srodrigc 132153323Srodrigc/* 133153323Srodrigc * Looks for the first behavior within a specified range of positions. 134153323Srodrigc * Return the associated behavior descriptor. Or NULL, if none found. 135153323Srodrigc */ 136153323Srodrigcbhv_desc_t * 137153323Srodrigcbhv_lookup_range(bhv_head_t *bhp, int low, int high) 138153323Srodrigc{ 139153323Srodrigc bhv_desc_t *curdesc; 140153323Srodrigc 141153323Srodrigc for (curdesc = bhp->bh_first; 142153323Srodrigc curdesc != NULL; 143153323Srodrigc curdesc = curdesc->bd_next) { 144153323Srodrigc 145153323Srodrigc int position = BHV_POSITION(curdesc); 146153323Srodrigc 147153323Srodrigc if (position <= high) { 148153323Srodrigc if (position >= low) 149153323Srodrigc return curdesc; 150153323Srodrigc return NULL; 151153323Srodrigc } 152153323Srodrigc } 153153323Srodrigc 154153323Srodrigc return NULL; 155153323Srodrigc} 156153323Srodrigc 157153323Srodrigc/* 158153323Srodrigc * Return the base behavior in the chain, or NULL if the chain 159153323Srodrigc * is empty. 160153323Srodrigc * 161153323Srodrigc * The caller has not read locked the behavior chain, so acquire the 162153323Srodrigc * lock before traversing the chain. 163153323Srodrigc */ 164153323Srodrigcbhv_desc_t * 165153323Srodrigcbhv_base(bhv_head_t *bhp) 166153323Srodrigc{ 167153323Srodrigc bhv_desc_t *curdesc; 168153323Srodrigc 169153323Srodrigc for (curdesc = bhp->bh_first; 170153323Srodrigc curdesc != NULL; 171153323Srodrigc curdesc = curdesc->bd_next) { 172153323Srodrigc 173153323Srodrigc if (curdesc->bd_next == NULL) { 174153323Srodrigc return curdesc; 175153323Srodrigc } 176153323Srodrigc } 177153323Srodrigc 178153323Srodrigc return NULL; 179153323Srodrigc} 180153323Srodrigc 181153323Srodrigcvoid 182153323Srodrigcbhv_head_init( 183153323Srodrigc bhv_head_t *bhp, 184153323Srodrigc char *name) 185153323Srodrigc{ 186153323Srodrigc bhp->bh_first = NULL; 187153323Srodrigc} 188153323Srodrigc 189153323Srodrigcvoid 190153323Srodrigcbhv_insert_initial( 191153323Srodrigc bhv_head_t *bhp, 192153323Srodrigc bhv_desc_t *bdp) 193153323Srodrigc{ 194153323Srodrigc ASSERT(bhp->bh_first == NULL); 195153323Srodrigc (bhp)->bh_first = bdp; 196153323Srodrigc} 197153323Srodrigc 198153323Srodrigcvoid 199153323Srodrigcbhv_head_destroy( 200153323Srodrigc bhv_head_t *bhp) 201153323Srodrigc{ 202153323Srodrigc ASSERT(bhp->bh_first == NULL); 203153323Srodrigc} 204