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chfs_vnode_cache.c revision 1.2 
      1 /*	$NetBSD: chfs_vnode_cache.c,v 1.2 2012/08/10 09:26:58 ttoth Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 Department of Software Engineering,
      5  *		      University of Szeged, Hungary
      6  * Copyright (C) 2010 Tamas Toth <ttoth (at) inf.u-szeged.hu>
      7  * Copyright (C) 2010 Adam Hoka <ahoka (at) NetBSD.org>
      8  * All rights reserved.
      9  *
     10  * This code is derived from software contributed to The NetBSD Foundation
     11  * by the Department of Software Engineering, University of Szeged, Hungary
     12  *
     13  * Redistribution and use in source and binary forms, with or without
     14  * modification, are permitted provided that the following conditions
     15  * are met:
     16  * 1. Redistributions of source code must retain the above copyright
     17  *    notice, this list of conditions and the following disclaimer.
     18  * 2. Redistributions in binary form must reproduce the above copyright
     19  *    notice, this list of conditions and the following disclaimer in the
     20  *    documentation and/or other materials provided with the distribution.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include "chfs.h"
     36 #include <sys/pool.h>
     37 
     38 struct chfs_vnode_cache **
     39 chfs_vnocache_hash_init(void)
     40 {
     41 	return kmem_zalloc(VNODECACHE_SIZE *
     42 	    sizeof(struct chfs_vnode_cache *), KM_SLEEP);
     43 }
     44 
     45 /**
     46  * chfs_get_vnode_cache - get a vnode_cache from the vnocache_hash
     47  * @chmp: fs super block info
     48  * @ino: inode for search
     49  * Returns the vnode_cache.
     50  */
     51 struct chfs_vnode_cache *
     52 chfs_vnode_cache_get(struct chfs_mount *chmp, ino_t vno)
     53 {
     54 	struct chfs_vnode_cache* ret;
     55 
     56 	KASSERT(mutex_owned(&chmp->chm_lock_vnocache));
     57 
     58 	ret = chmp->chm_vnocache_hash[vno % VNODECACHE_SIZE];
     59 
     60 	if (ret == NULL) {
     61 		return NULL;
     62 	}
     63 
     64 	while (ret && ret->vno < vno) {
     65 		ret = ret->next;
     66 	}
     67 
     68 	if (ret && ret->vno != vno) {
     69 		ret = NULL;
     70 	}
     71 
     72 	return ret;
     73 }
     74 
     75 /**
     76  * chfs_add_vnode_cache - add a vnode_cache to the vnocache_hash
     77  * @chmp: fs super block info
     78  * @new: new vnode_cache
     79  */
     80 void
     81 chfs_vnode_cache_add(struct chfs_mount *chmp,
     82     struct chfs_vnode_cache* new)
     83 {
     84 	struct chfs_vnode_cache** prev;
     85 
     86 	KASSERT(mutex_owned(&chmp->chm_lock_vnocache));
     87 
     88 	if (!new->vno) {
     89 		new->vno = ++chmp->chm_max_vno;
     90 	}
     91 
     92 	prev = &chmp->chm_vnocache_hash[new->vno % VNODECACHE_SIZE];
     93 
     94 	while ((*prev) && (*prev)->vno < new->vno) {
     95 		prev = &((*prev)->next);
     96 	}
     97 	new->next = *prev;
     98 	*prev = new;
     99 }
    100 
    101 /**
    102  * chfs_del_vnode_cache - del a vnode_cache from the vnocache_hash
    103  * @chmp: fs super block info
    104  * @old: old vnode_cache
    105  */
    106 void
    107 chfs_vnode_cache_remove(struct chfs_mount *chmp,
    108     struct chfs_vnode_cache* old)
    109 {
    110 	struct chfs_vnode_cache** prev;
    111 
    112 	KASSERT(mutex_owned(&chmp->chm_lock_vnocache));
    113 
    114 	prev = &chmp->chm_vnocache_hash[old->vno % VNODECACHE_SIZE];
    115 	while ((*prev) && (*prev)->vno < old->vno) {
    116 		prev = &(*prev)->next;
    117 	}
    118 
    119 	if ((*prev) == old) {
    120 		*prev = old->next;
    121 	}
    122 
    123 	if (old->state != VNO_STATE_READING &&
    124 	    old->state != VNO_STATE_CLEARING) {
    125 		chfs_vnode_cache_free(old);
    126 	}
    127 }
    128 
    129 /**
    130  * chfs_free_vnode_caches - free the vnocache_hash
    131  * @chmp: fs super block info
    132  */
    133 void
    134 chfs_vnocache_hash_destroy(struct chfs_vnode_cache **hash)
    135 {
    136 	struct chfs_vnode_cache *this, *next;
    137 	int i;
    138 
    139 	for (i = 0; i < VNODECACHE_SIZE; i++) {
    140 		this = hash[i];
    141 		while (this) {
    142 			next = this->next;
    143 			chfs_vnode_cache_free(this);
    144 			this = next;
    145 		}
    146 		hash[i] = NULL;
    147 	}
    148 }
    149 
    150 
    151