1 /* $NetBSD: dm_pdev.c,v 1.8 2010/12/23 14:58:13 mlelstv 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 struct pathbuf *dev_pb; 88 dm_pdev_t *dmp; 89 int error; 90 91 KASSERT(dev_name != NULL); 92 93 mutex_enter(&dm_pdev_mutex); 94 dmp = dm_pdev_lookup_name(dev_name); 95 96 if (dmp != NULL) { 97 dmp->ref_cnt++; 98 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name); 99 mutex_exit(&dm_pdev_mutex); 100 return dmp; 101 } 102 mutex_exit(&dm_pdev_mutex); 103 104 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) 105 return NULL; 106 107 dev_pb = pathbuf_create(dev_name); 108 if (dev_pb == NULL) { 109 aprint_debug("pathbuf_create on device: %s failed!\n", 110 dev_name); 111 kmem_free(dmp, sizeof(dm_pdev_t)); 112 return NULL; 113 } 114 error = dk_lookup(dev_pb, curlwp, &dmp->pdev_vnode); 115 pathbuf_destroy(dev_pb); 116 if (error) { 117 aprint_debug("dk_lookup on device: %s failed with error %d!\n", 118 dev_name, error); 119 kmem_free(dmp, sizeof(dm_pdev_t)); 120 return NULL; 121 } 122 getdisksize(dmp->pdev_vnode, &dmp->pdev_numsec, &dmp->pdev_secsize); 123 dmp->ref_cnt = 1; 124 125 mutex_enter(&dm_pdev_mutex); 126 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 127 mutex_exit(&dm_pdev_mutex); 128 129 return dmp; 130 } 131 /* 132 * Initialize pdev subsystem. 133 */ 134 int 135 dm_pdev_init(void) 136 { 137 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 138 mutex_init(&dm_pdev_mutex, MUTEX_DEFAULT, IPL_NONE); 139 140 return 0; 141 } 142 /* 143 * Allocat new pdev structure if is not already present and 144 * set name. 145 */ 146 static dm_pdev_t * 147 dm_pdev_alloc(const char *name) 148 { 149 dm_pdev_t *dmp; 150 151 if ((dmp = kmem_zalloc(sizeof(dm_pdev_t), KM_SLEEP)) == NULL) 152 return NULL; 153 154 strlcpy(dmp->name, name, MAX_DEV_NAME); 155 156 dmp->ref_cnt = 0; 157 dmp->pdev_vnode = NULL; 158 159 return dmp; 160 } 161 /* 162 * Destroy allocated dm_pdev. 163 */ 164 static int 165 dm_pdev_rem(dm_pdev_t * dmp) 166 { 167 int err; 168 169 KASSERT(dmp != NULL); 170 171 if (dmp->pdev_vnode != NULL) { 172 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, FSCRED); 173 if (err != 0) 174 return err; 175 } 176 kmem_free(dmp, sizeof(*dmp)); 177 dmp = NULL; 178 179 return 0; 180 } 181 /* 182 * Destroy all existing pdev's in device-mapper. 183 */ 184 int 185 dm_pdev_destroy(void) 186 { 187 dm_pdev_t *dm_pdev; 188 189 mutex_enter(&dm_pdev_mutex); 190 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ 191 192 dm_pdev = SLIST_FIRST(&dm_pdev_list); 193 194 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); 195 196 dm_pdev_rem(dm_pdev); 197 } 198 mutex_exit(&dm_pdev_mutex); 199 200 mutex_destroy(&dm_pdev_mutex); 201 return 0; 202 } 203 /* 204 * This funcion is called from dm_dev_remove_ioctl. 205 * When I'm removing device from list, I have to decrement 206 * reference counter. If reference counter is 0 I will remove 207 * dmp from global list and from device list to. And I will CLOSE 208 * dmp vnode too. 209 */ 210 211 /* 212 * Decrement pdev reference counter if 0 remove it. 213 */ 214 int 215 dm_pdev_decr(dm_pdev_t * dmp) 216 { 217 KASSERT(dmp != NULL); 218 /* 219 * If this was last reference remove dmp from 220 * global list also. 221 */ 222 mutex_enter(&dm_pdev_mutex); 223 224 if (--dmp->ref_cnt == 0) { 225 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 226 mutex_exit(&dm_pdev_mutex); 227 dm_pdev_rem(dmp); 228 return 0; 229 } 230 mutex_exit(&dm_pdev_mutex); 231 return 0; 232 } 233 /*static int 234 dm_pdev_dump_list(void) 235 { 236 dm_pdev_t *dmp; 237 238 aprint_verbose("Dumping dm_pdev_list \n"); 239 240 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) { 241 aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n", 242 dmp->name, dmp->ref_cnt, dmp->list_ref_cnt); 243 } 244 245 return 0; 246 247 }*/ 248