1*fa9e4066Sahrens /* 2*fa9e4066Sahrens * CDDL HEADER START 3*fa9e4066Sahrens * 4*fa9e4066Sahrens * The contents of this file are subject to the terms of the 5*fa9e4066Sahrens * Common Development and Distribution License, Version 1.0 only 6*fa9e4066Sahrens * (the "License"). You may not use this file except in compliance 7*fa9e4066Sahrens * with the License. 8*fa9e4066Sahrens * 9*fa9e4066Sahrens * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*fa9e4066Sahrens * or http://www.opensolaris.org/os/licensing. 11*fa9e4066Sahrens * See the License for the specific language governing permissions 12*fa9e4066Sahrens * and limitations under the License. 13*fa9e4066Sahrens * 14*fa9e4066Sahrens * When distributing Covered Code, include this CDDL HEADER in each 15*fa9e4066Sahrens * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*fa9e4066Sahrens * If applicable, add the following below this CDDL HEADER, with the 17*fa9e4066Sahrens * fields enclosed by brackets "[]" replaced with your own identifying 18*fa9e4066Sahrens * information: Portions Copyright [yyyy] [name of copyright owner] 19*fa9e4066Sahrens * 20*fa9e4066Sahrens * CDDL HEADER END 21*fa9e4066Sahrens */ 22*fa9e4066Sahrens /* 23*fa9e4066Sahrens * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24*fa9e4066Sahrens * Use is subject to license terms. 25*fa9e4066Sahrens */ 26*fa9e4066Sahrens 27*fa9e4066Sahrens #pragma ident "%Z%%M% %I% %E% SMI" 28*fa9e4066Sahrens 29*fa9e4066Sahrens #include <sys/zfs_context.h> 30*fa9e4066Sahrens #include <sys/refcount.h> 31*fa9e4066Sahrens 32*fa9e4066Sahrens #if defined(DEBUG) || !defined(_KERNEL) 33*fa9e4066Sahrens 34*fa9e4066Sahrens #ifdef _KERNEL 35*fa9e4066Sahrens int reference_tracking_enable = FALSE; /* runs out of memory too easily */ 36*fa9e4066Sahrens #else 37*fa9e4066Sahrens int reference_tracking_enable = TRUE; 38*fa9e4066Sahrens #endif 39*fa9e4066Sahrens int reference_history = 4; /* tunable */ 40*fa9e4066Sahrens 41*fa9e4066Sahrens static kmem_cache_t *reference_cache; 42*fa9e4066Sahrens static kmem_cache_t *reference_history_cache; 43*fa9e4066Sahrens 44*fa9e4066Sahrens void 45*fa9e4066Sahrens refcount_init(void) 46*fa9e4066Sahrens { 47*fa9e4066Sahrens reference_cache = kmem_cache_create("reference_cache", 48*fa9e4066Sahrens sizeof (reference_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 49*fa9e4066Sahrens 50*fa9e4066Sahrens reference_history_cache = kmem_cache_create("reference_history_cache", 51*fa9e4066Sahrens sizeof (uint64_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 52*fa9e4066Sahrens } 53*fa9e4066Sahrens 54*fa9e4066Sahrens void 55*fa9e4066Sahrens refcount_fini(void) 56*fa9e4066Sahrens { 57*fa9e4066Sahrens kmem_cache_destroy(reference_cache); 58*fa9e4066Sahrens kmem_cache_destroy(reference_history_cache); 59*fa9e4066Sahrens } 60*fa9e4066Sahrens 61*fa9e4066Sahrens void 62*fa9e4066Sahrens refcount_create(refcount_t *rc) 63*fa9e4066Sahrens { 64*fa9e4066Sahrens list_create(&rc->rc_list, sizeof (reference_t), 65*fa9e4066Sahrens offsetof(reference_t, ref_link)); 66*fa9e4066Sahrens list_create(&rc->rc_removed, sizeof (reference_t), 67*fa9e4066Sahrens offsetof(reference_t, ref_link)); 68*fa9e4066Sahrens mutex_init(&rc->rc_mtx, NULL, MUTEX_DEFAULT, NULL); 69*fa9e4066Sahrens } 70*fa9e4066Sahrens 71*fa9e4066Sahrens void 72*fa9e4066Sahrens refcount_destroy_many(refcount_t *rc, uint64_t number) 73*fa9e4066Sahrens { 74*fa9e4066Sahrens reference_t *ref; 75*fa9e4066Sahrens 76*fa9e4066Sahrens ASSERT(rc->rc_count == number); 77*fa9e4066Sahrens while (ref = list_head(&rc->rc_list)) { 78*fa9e4066Sahrens list_remove(&rc->rc_list, ref); 79*fa9e4066Sahrens kmem_cache_free(reference_cache, ref); 80*fa9e4066Sahrens } 81*fa9e4066Sahrens list_destroy(&rc->rc_list); 82*fa9e4066Sahrens 83*fa9e4066Sahrens while (ref = list_head(&rc->rc_removed)) { 84*fa9e4066Sahrens list_remove(&rc->rc_removed, ref); 85*fa9e4066Sahrens kmem_cache_free(reference_history_cache, ref->ref_removed); 86*fa9e4066Sahrens kmem_cache_free(reference_cache, ref); 87*fa9e4066Sahrens } 88*fa9e4066Sahrens list_destroy(&rc->rc_removed); 89*fa9e4066Sahrens mutex_destroy(&rc->rc_mtx); 90*fa9e4066Sahrens } 91*fa9e4066Sahrens 92*fa9e4066Sahrens void 93*fa9e4066Sahrens refcount_destroy(refcount_t *rc) 94*fa9e4066Sahrens { 95*fa9e4066Sahrens refcount_destroy_many(rc, 0); 96*fa9e4066Sahrens } 97*fa9e4066Sahrens 98*fa9e4066Sahrens int 99*fa9e4066Sahrens refcount_is_zero(refcount_t *rc) 100*fa9e4066Sahrens { 101*fa9e4066Sahrens ASSERT(rc->rc_count >= 0); 102*fa9e4066Sahrens return (rc->rc_count == 0); 103*fa9e4066Sahrens } 104*fa9e4066Sahrens 105*fa9e4066Sahrens int64_t 106*fa9e4066Sahrens refcount_count(refcount_t *rc) 107*fa9e4066Sahrens { 108*fa9e4066Sahrens ASSERT(rc->rc_count >= 0); 109*fa9e4066Sahrens return (rc->rc_count); 110*fa9e4066Sahrens } 111*fa9e4066Sahrens 112*fa9e4066Sahrens int64_t 113*fa9e4066Sahrens refcount_add_many(refcount_t *rc, uint64_t number, void *holder) 114*fa9e4066Sahrens { 115*fa9e4066Sahrens reference_t *ref; 116*fa9e4066Sahrens int64_t count; 117*fa9e4066Sahrens 118*fa9e4066Sahrens if (reference_tracking_enable) { 119*fa9e4066Sahrens ref = kmem_cache_alloc(reference_cache, KM_SLEEP); 120*fa9e4066Sahrens ref->ref_holder = holder; 121*fa9e4066Sahrens ref->ref_number = number; 122*fa9e4066Sahrens } 123*fa9e4066Sahrens mutex_enter(&rc->rc_mtx); 124*fa9e4066Sahrens ASSERT(rc->rc_count >= 0); 125*fa9e4066Sahrens if (reference_tracking_enable) 126*fa9e4066Sahrens list_insert_head(&rc->rc_list, ref); 127*fa9e4066Sahrens rc->rc_count += number; 128*fa9e4066Sahrens count = rc->rc_count; 129*fa9e4066Sahrens mutex_exit(&rc->rc_mtx); 130*fa9e4066Sahrens 131*fa9e4066Sahrens return (count); 132*fa9e4066Sahrens } 133*fa9e4066Sahrens 134*fa9e4066Sahrens int64_t 135*fa9e4066Sahrens refcount_add(refcount_t *rc, void *holder) 136*fa9e4066Sahrens { 137*fa9e4066Sahrens return (refcount_add_many(rc, 1, holder)); 138*fa9e4066Sahrens } 139*fa9e4066Sahrens 140*fa9e4066Sahrens int64_t 141*fa9e4066Sahrens refcount_remove_many(refcount_t *rc, uint64_t number, void *holder) 142*fa9e4066Sahrens { 143*fa9e4066Sahrens reference_t *ref; 144*fa9e4066Sahrens int64_t count; 145*fa9e4066Sahrens 146*fa9e4066Sahrens mutex_enter(&rc->rc_mtx); 147*fa9e4066Sahrens ASSERT(rc->rc_count >= number); 148*fa9e4066Sahrens 149*fa9e4066Sahrens if (!reference_tracking_enable) { 150*fa9e4066Sahrens rc->rc_count -= number; 151*fa9e4066Sahrens count = rc->rc_count; 152*fa9e4066Sahrens mutex_exit(&rc->rc_mtx); 153*fa9e4066Sahrens return (count); 154*fa9e4066Sahrens } 155*fa9e4066Sahrens 156*fa9e4066Sahrens for (ref = list_head(&rc->rc_list); ref; 157*fa9e4066Sahrens ref = list_next(&rc->rc_list, ref)) { 158*fa9e4066Sahrens if (ref->ref_holder == holder && ref->ref_number == number) { 159*fa9e4066Sahrens list_remove(&rc->rc_list, ref); 160*fa9e4066Sahrens if (reference_history > 0) { 161*fa9e4066Sahrens ref->ref_removed = 162*fa9e4066Sahrens kmem_cache_alloc(reference_history_cache, 163*fa9e4066Sahrens KM_SLEEP); 164*fa9e4066Sahrens list_insert_head(&rc->rc_removed, ref); 165*fa9e4066Sahrens rc->rc_removed_count++; 166*fa9e4066Sahrens if (rc->rc_removed_count >= reference_history) { 167*fa9e4066Sahrens ref = list_tail(&rc->rc_removed); 168*fa9e4066Sahrens list_remove(&rc->rc_removed, ref); 169*fa9e4066Sahrens kmem_cache_free(reference_history_cache, 170*fa9e4066Sahrens ref->ref_removed); 171*fa9e4066Sahrens kmem_cache_free(reference_cache, ref); 172*fa9e4066Sahrens rc->rc_removed_count--; 173*fa9e4066Sahrens } 174*fa9e4066Sahrens } else { 175*fa9e4066Sahrens kmem_cache_free(reference_cache, ref); 176*fa9e4066Sahrens } 177*fa9e4066Sahrens rc->rc_count -= number; 178*fa9e4066Sahrens count = rc->rc_count; 179*fa9e4066Sahrens mutex_exit(&rc->rc_mtx); 180*fa9e4066Sahrens return (count); 181*fa9e4066Sahrens } 182*fa9e4066Sahrens } 183*fa9e4066Sahrens panic("No such hold %p on refcount %llx", holder, 184*fa9e4066Sahrens (u_longlong_t)(uintptr_t)rc); 185*fa9e4066Sahrens return (-1); 186*fa9e4066Sahrens } 187*fa9e4066Sahrens 188*fa9e4066Sahrens int64_t 189*fa9e4066Sahrens refcount_remove(refcount_t *rc, void *holder) 190*fa9e4066Sahrens { 191*fa9e4066Sahrens return (refcount_remove_many(rc, 1, holder)); 192*fa9e4066Sahrens } 193*fa9e4066Sahrens 194*fa9e4066Sahrens #endif 195