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/malloc.h> 38 #include <sys/namei.h> 39 #include <sys/vnode.h> 40 #include <sys/nlookup.h> 41 42 #include "dm.h" 43 44 SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list; 45 46 struct lock dm_pdev_mutex; 47 48 static dm_pdev_t *dm_pdev_alloc(const char *); 49 static int dm_pdev_rem(dm_pdev_t *); 50 static dm_pdev_t *dm_pdev_lookup_name(const char *); 51 52 /* 53 * Find used pdev with name == dm_pdev_name. 54 */ 55 dm_pdev_t * 56 dm_pdev_lookup_name(const char *dm_pdev_name) 57 { 58 dm_pdev_t *dm_pdev; 59 int dlen; 60 int slen; 61 62 KKASSERT(dm_pdev_name != NULL); 63 64 slen = strlen(dm_pdev_name); 65 66 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) { 67 dlen = strlen(dm_pdev->name); 68 69 if (slen != dlen) 70 continue; 71 72 if (strncmp(dm_pdev_name, dm_pdev->name, slen) == 0) 73 return dm_pdev; 74 } 75 76 return NULL; 77 } 78 79 static int 80 dm_dk_lookup(const char *dev_name, struct vnode **vpp) 81 { 82 struct nlookupdata nd; 83 int error; 84 85 #ifdef notyet 86 if (this is a root mount) { 87 error = vn_opendisk(dev_name, FREAD|FWRITE, vpp); 88 return error; 89 } 90 #endif 91 92 error = nlookup_init(&nd, dev_name, UIO_SYSSPACE, NLC_FOLLOW); 93 if (error) 94 return error; 95 96 error = vn_open(&nd, NULL, FREAD|FWRITE, 0); 97 *vpp = nd.nl_open_vp; 98 nd.nl_open_vp = NULL; 99 nlookup_done(&nd); 100 101 return 0; 102 } 103 104 /* 105 * Create entry for device with name dev_name and open vnode for it. 106 * If entry already exists in global SLIST I will only increment 107 * reference counter. 108 */ 109 dm_pdev_t * 110 dm_pdev_insert(const char *dev_name) 111 { 112 dm_pdev_t *dmp; 113 int error; 114 115 KKASSERT(dev_name != NULL); 116 117 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 118 dmp = dm_pdev_lookup_name(dev_name); 119 120 if (dmp != NULL) { 121 dmp->ref_cnt++; 122 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name); 123 lockmgr(&dm_pdev_mutex, LK_RELEASE); 124 return dmp; 125 } 126 lockmgr(&dm_pdev_mutex, LK_RELEASE); 127 128 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) 129 return NULL; 130 131 /* XXX: nlookup and/or vn_opendisk */ 132 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode); 133 if (error) { 134 aprint_debug("dk_lookup on device: %s failed with error %d!\n", 135 dev_name, error); 136 kfree(dmp, M_DM); 137 return NULL; 138 } 139 dmp->ref_cnt = 1; 140 141 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 142 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 143 lockmgr(&dm_pdev_mutex, LK_RELEASE); 144 145 return dmp; 146 } 147 /* 148 * Initialize pdev subsystem. 149 */ 150 int 151 dm_pdev_init(void) 152 { 153 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 154 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE); 155 156 return 0; 157 } 158 /* 159 * Allocat new pdev structure if is not already present and 160 * set name. 161 */ 162 static dm_pdev_t * 163 dm_pdev_alloc(const char *name) 164 { 165 dm_pdev_t *dmp; 166 167 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL) 168 return NULL; 169 170 strlcpy(dmp->name, name, MAX_DEV_NAME); 171 172 dmp->ref_cnt = 0; 173 dmp->pdev_vnode = NULL; 174 175 return dmp; 176 } 177 /* 178 * Destroy allocated dm_pdev. 179 */ 180 static int 181 dm_pdev_rem(dm_pdev_t * dmp) 182 { 183 int err; 184 185 KKASSERT(dmp != NULL); 186 187 if (dmp->pdev_vnode != NULL) { 188 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE); 189 if (err != 0) 190 return err; 191 } 192 kfree(dmp, M_DM); 193 dmp = NULL; 194 195 return 0; 196 } 197 /* 198 * Destroy all existing pdev's in device-mapper. 199 */ 200 int 201 dm_pdev_destroy(void) 202 { 203 dm_pdev_t *dm_pdev; 204 205 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 206 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ 207 208 dm_pdev = SLIST_FIRST(&dm_pdev_list); 209 210 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); 211 212 dm_pdev_rem(dm_pdev); 213 } 214 lockmgr(&dm_pdev_mutex, LK_RELEASE); 215 216 lockuninit(&dm_pdev_mutex); 217 return 0; 218 } 219 /* 220 * This funcion is called from dm_dev_remove_ioctl. 221 * When I'm removing device from list, I have to decrement 222 * reference counter. If reference counter is 0 I will remove 223 * dmp from global list and from device list to. And I will CLOSE 224 * dmp vnode too. 225 */ 226 227 /* 228 * Decrement pdev reference counter if 0 remove it. 229 */ 230 int 231 dm_pdev_decr(dm_pdev_t * dmp) 232 { 233 KKASSERT(dmp != NULL); 234 /* 235 * If this was last reference remove dmp from 236 * global list also. 237 */ 238 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 239 240 if (--dmp->ref_cnt == 0) { 241 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 242 lockmgr(&dm_pdev_mutex, LK_RELEASE); 243 dm_pdev_rem(dmp); 244 return 0; 245 } 246 lockmgr(&dm_pdev_mutex, LK_RELEASE); 247 return 0; 248 } 249 /*static int 250 dm_pdev_dump_list(void) 251 { 252 dm_pdev_t *dmp; 253 254 aprint_verbose("Dumping dm_pdev_list \n"); 255 256 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) { 257 aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n", 258 dmp->name, dmp->ref_cnt, dmp->list_ref_cnt); 259 } 260 261 return 0; 262 263 }*/ 264