1 /* $NetBSD: dm_pdev.c,v 1.6 2010/01/04 00:19:08 haad Exp $ */ 2 3 /* 4 * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Adam Hamsik. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/types.h> 33 #include <sys/param.h> 34 35 #include <sys/disk.h> 36 #include <sys/fcntl.h> 37 #include <sys/kmem.h> 38 #include <sys/namei.h> 39 #include <sys/vnode.h> 40 41 #include <dev/dkvar.h> 42 43 #include "dm.h" 44 45 SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list; 46 47 kmutex_t dm_pdev_mutex; 48 49 static dm_pdev_t *dm_pdev_alloc(const char *); 50 static int dm_pdev_rem(dm_pdev_t *); 51 static dm_pdev_t *dm_pdev_lookup_name(const char *); 52 53 /* 54 * Find used pdev with name == dm_pdev_name. 55 */ 56 dm_pdev_t * 57 dm_pdev_lookup_name(const char *dm_pdev_name) 58 { 59 dm_pdev_t *dm_pdev; 60 int dlen; 61 int slen; 62 63 KASSERT(dm_pdev_name != NULL); 64 65 slen = strlen(dm_pdev_name); 66 67 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) { 68 dlen = strlen(dm_pdev->name); 69 70 if (slen != dlen) 71 continue; 72 73 if (strncmp(dm_pdev_name, dm_pdev->name, slen) == 0) 74 return dm_pdev; 75 } 76 77 return NULL; 78 } 79 /* 80 * Create entry for device with name dev_name and open vnode for it. 81 * If entry already exists in global SLIST I will only increment 82 * reference counter. 83 */ 84 dm_pdev_t * 85 dm_pdev_insert(const char *dev_name) 86 { 87 dm_pdev_t *dmp; 88 int error; 89 90 KASSERT(dev_name != NULL); 91 92 mutex_enter(&dm_pdev_mutex); 93 dmp = dm_pdev_lookup_name(dev_name); 94 95 if (dmp != NULL) { 96 dmp->ref_cnt++; 97 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name); 98 mutex_exit(&dm_pdev_mutex); 99 return dmp; 100 } 101 mutex_exit(&dm_pdev_mutex); 102 103 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) 104 return NULL; 105 106 error = dk_lookup(dev_name, curlwp, &dmp->pdev_vnode, UIO_SYSSPACE); 107 if (error) { 108 aprint_debug("dk_lookup on device: %s failed with error %d!\n", 109 dev_name, error); 110 kmem_free(dmp, sizeof(dm_pdev_t)); 111 return NULL; 112 } 113 dmp->ref_cnt = 1; 114 115 mutex_enter(&dm_pdev_mutex); 116 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 117 mutex_exit(&dm_pdev_mutex); 118 119 return dmp; 120 } 121 /* 122 * Initialize pdev subsystem. 123 */ 124 int 125 dm_pdev_init(void) 126 { 127 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 128 mutex_init(&dm_pdev_mutex, MUTEX_DEFAULT, IPL_NONE); 129 130 return 0; 131 } 132 /* 133 * Allocat new pdev structure if is not already present and 134 * set name. 135 */ 136 static dm_pdev_t * 137 dm_pdev_alloc(const char *name) 138 { 139 dm_pdev_t *dmp; 140 141 if ((dmp = kmem_zalloc(sizeof(dm_pdev_t), KM_SLEEP)) == NULL) 142 return NULL; 143 144 strlcpy(dmp->name, name, MAX_DEV_NAME); 145 146 dmp->ref_cnt = 0; 147 dmp->pdev_vnode = NULL; 148 149 return dmp; 150 } 151 /* 152 * Destroy allocated dm_pdev. 153 */ 154 static int 155 dm_pdev_rem(dm_pdev_t * dmp) 156 { 157 int err; 158 159 KASSERT(dmp != NULL); 160 161 if (dmp->pdev_vnode != NULL) { 162 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, FSCRED); 163 if (err != 0) 164 return err; 165 } 166 kmem_free(dmp, sizeof(*dmp)); 167 dmp = NULL; 168 169 return 0; 170 } 171 /* 172 * Destroy all existing pdev's in device-mapper. 173 */ 174 int 175 dm_pdev_destroy(void) 176 { 177 dm_pdev_t *dm_pdev; 178 179 mutex_enter(&dm_pdev_mutex); 180 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ 181 182 dm_pdev = SLIST_FIRST(&dm_pdev_list); 183 184 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); 185 186 dm_pdev_rem(dm_pdev); 187 } 188 mutex_exit(&dm_pdev_mutex); 189 190 mutex_destroy(&dm_pdev_mutex); 191 return 0; 192 } 193 /* 194 * This funcion is called from dm_dev_remove_ioctl. 195 * When I'm removing device from list, I have to decrement 196 * reference counter. If reference counter is 0 I will remove 197 * dmp from global list and from device list to. And I will CLOSE 198 * dmp vnode too. 199 */ 200 201 /* 202 * Decrement pdev reference counter if 0 remove it. 203 */ 204 int 205 dm_pdev_decr(dm_pdev_t * dmp) 206 { 207 KASSERT(dmp != NULL); 208 /* 209 * If this was last reference remove dmp from 210 * global list also. 211 */ 212 mutex_enter(&dm_pdev_mutex); 213 214 if (--dmp->ref_cnt == 0) { 215 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 216 mutex_exit(&dm_pdev_mutex); 217 dm_pdev_rem(dmp); 218 return 0; 219 } 220 mutex_exit(&dm_pdev_mutex); 221 return 0; 222 } 223 /*static int 224 dm_pdev_dump_list(void) 225 { 226 dm_pdev_t *dmp; 227 228 aprint_verbose("Dumping dm_pdev_list \n"); 229 230 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) { 231 aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n", 232 dmp->name, dmp->ref_cnt, dmp->list_ref_cnt); 233 } 234 235 return 0; 236 237 }*/ 238