1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #ifndef _LAYOUT_DEVICE_CACHE_H 28*0Sstevel@tonic-gate #define _LAYOUT_DEVICE_CACHE_H 29*0Sstevel@tonic-gate 30*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 31*0Sstevel@tonic-gate 32*0Sstevel@tonic-gate #ifdef __cplusplus 33*0Sstevel@tonic-gate extern "C" { 34*0Sstevel@tonic-gate #endif 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate /* 37*0Sstevel@tonic-gate * This module manages cached copies of a dm_descriptor_t's nvpair 38*0Sstevel@tonic-gate * list of attributes and its device name. The caches are used to 39*0Sstevel@tonic-gate * make sure that the memory allocated to these objects is correctly 40*0Sstevel@tonic-gate * released after the layout process has finished. The cached attrs 41*0Sstevel@tonic-gate * also allow the layout code to store and retrieve transient, 42*0Sstevel@tonic-gate * layout-private data in the same data structure as the other 43*0Sstevel@tonic-gate * relevant device information. 44*0Sstevel@tonic-gate * 45*0Sstevel@tonic-gate * There are two primary caches of information: 46*0Sstevel@tonic-gate * 47*0Sstevel@tonic-gate * descriptor->name - which maps a dm_descriptor_t handle to 48*0Sstevel@tonic-gate * the associated device's name 49*0Sstevel@tonic-gate * 50*0Sstevel@tonic-gate * name->attributes - which maps a device name to an nvlist_t 51*0Sstevel@tonic-gate * attribute collection. 52*0Sstevel@tonic-gate * 53*0Sstevel@tonic-gate * These two data structures thus allow the following lookup chain: 54*0Sstevel@tonic-gate * descriptor->name->attributes. 55*0Sstevel@tonic-gate * 56*0Sstevel@tonic-gate * The attributes are accessed by device name because the it is the 57*0Sstevel@tonic-gate * unique identifier for the device. The descriptor returned by 58*0Sstevel@tonic-gate * libdiskmgt is just an arbitrary handle, multiple calls into the 59*0Sstevel@tonic-gate * library may return different descriptors for the same device. 60*0Sstevel@tonic-gate * 61*0Sstevel@tonic-gate * Descriptors are also get re-cycled by the library which could 62*0Sstevel@tonic-gate * result in the same descriptor being used to represent different 63*0Sstevel@tonic-gate * devices (although not concurrently). To prevent such recycling 64*0Sstevel@tonic-gate * all of the descriptors are held until the layout process has 65*0Sstevel@tonic-gate * completed. 66*0Sstevel@tonic-gate * 67*0Sstevel@tonic-gate * Performance testing indicated that searching the lists of known 68*0Sstevel@tonic-gate * devices by display (CTD or DID) name or alias was a significant 69*0Sstevel@tonic-gate * bottleneck. A mapping from display name to descriptor was added 70*0Sstevel@tonic-gate * to address this. 71*0Sstevel@tonic-gate * 72*0Sstevel@tonic-gate * The module should be initialized once by calling create_device_caches() 73*0Sstevel@tonic-gate * prior to any call which accesses data maintained by the cache. 74*0Sstevel@tonic-gate * 75*0Sstevel@tonic-gate * The caches should be flushed after all accesses have completed by 76*0Sstevel@tonic-gate * calling release_device_caches. 77*0Sstevel@tonic-gate */ 78*0Sstevel@tonic-gate 79*0Sstevel@tonic-gate #include "libdiskmgt.h" 80*0Sstevel@tonic-gate #include "layout_device_util.h" 81*0Sstevel@tonic-gate 82*0Sstevel@tonic-gate extern int create_device_caches(); 83*0Sstevel@tonic-gate extern int release_device_caches(); 84*0Sstevel@tonic-gate 85*0Sstevel@tonic-gate extern int add_cached_descriptor(char *name, dm_descriptor_t desc); 86*0Sstevel@tonic-gate extern dm_descriptor_t find_cached_descriptor(char *name); 87*0Sstevel@tonic-gate 88*0Sstevel@tonic-gate extern int add_cached_name(dm_descriptor_t desc, char *name); 89*0Sstevel@tonic-gate extern int get_name(dm_descriptor_t desc, char **name); 90*0Sstevel@tonic-gate 91*0Sstevel@tonic-gate extern int add_cached_attributes(char *name, nvlist_t *attrs); 92*0Sstevel@tonic-gate extern int get_cached_attributes(dm_descriptor_t desc, nvlist_t **list); 93*0Sstevel@tonic-gate 94*0Sstevel@tonic-gate extern int new_descriptor(dm_descriptor_t *desc); 95*0Sstevel@tonic-gate extern int add_descriptors_to_free(dm_descriptor_t *desc_list); 96*0Sstevel@tonic-gate 97*0Sstevel@tonic-gate #ifdef __cplusplus 98*0Sstevel@tonic-gate } 99*0Sstevel@tonic-gate #endif 100*0Sstevel@tonic-gate 101*0Sstevel@tonic-gate #endif /* _LAYOUT_DEVICE_CACHE_H */ 102