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 off_t 105 dm_pdev_correct_dump_offset(dm_pdev_t *pdev, off_t offset) 106 { 107 off_t noffset; 108 109 noffset = pdev->pdev_pinfo.reserved_blocks + 110 pdev->pdev_pinfo.media_offset / pdev->pdev_pinfo.media_blksize; 111 noffset *= DEV_BSIZE; 112 noffset += offset; 113 114 return noffset; 115 } 116 117 /* 118 * Create entry for device with name dev_name and open vnode for it. 119 * If entry already exists in global SLIST I will only increment 120 * reference counter. 121 */ 122 dm_pdev_t * 123 dm_pdev_insert(const char *dev_name) 124 { 125 dm_pdev_t *dmp; 126 int error; 127 128 KKASSERT(dev_name != NULL); 129 130 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 131 dmp = dm_pdev_lookup_name(dev_name); 132 133 if (dmp != NULL) { 134 dmp->ref_cnt++; 135 aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name); 136 lockmgr(&dm_pdev_mutex, LK_RELEASE); 137 return dmp; 138 } 139 lockmgr(&dm_pdev_mutex, LK_RELEASE); 140 141 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) 142 return NULL; 143 144 /* XXX: nlookup and/or vn_opendisk */ 145 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode); 146 if (error) { 147 aprint_debug("dk_lookup on device: %s failed with error %d!\n", 148 dev_name, error); 149 kfree(dmp, M_DM); 150 return NULL; 151 } 152 dmp->ref_cnt = 1; 153 154 /* 155 * Get us the partinfo from the underlying device, it's needed for 156 * dumps. 157 */ 158 bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo)); 159 error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART, 160 (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL); 161 162 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 163 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 164 lockmgr(&dm_pdev_mutex, LK_RELEASE); 165 166 return dmp; 167 } 168 /* 169 * Initialize pdev subsystem. 170 */ 171 int 172 dm_pdev_init(void) 173 { 174 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 175 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE); 176 177 return 0; 178 } 179 /* 180 * Allocat new pdev structure if is not already present and 181 * set name. 182 */ 183 static dm_pdev_t * 184 dm_pdev_alloc(const char *name) 185 { 186 dm_pdev_t *dmp; 187 188 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL) 189 return NULL; 190 191 strlcpy(dmp->name, name, MAX_DEV_NAME); 192 193 dmp->ref_cnt = 0; 194 dmp->pdev_vnode = NULL; 195 196 return dmp; 197 } 198 /* 199 * Destroy allocated dm_pdev. 200 */ 201 static int 202 dm_pdev_rem(dm_pdev_t * dmp) 203 { 204 int err; 205 206 KKASSERT(dmp != NULL); 207 208 if (dmp->pdev_vnode != NULL) { 209 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE); 210 if (err != 0) 211 return err; 212 } 213 kfree(dmp, M_DM); 214 dmp = NULL; 215 216 return 0; 217 } 218 /* 219 * Destroy all existing pdev's in device-mapper. 220 */ 221 int 222 dm_pdev_destroy(void) 223 { 224 dm_pdev_t *dm_pdev; 225 226 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 227 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ 228 229 dm_pdev = SLIST_FIRST(&dm_pdev_list); 230 231 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); 232 233 dm_pdev_rem(dm_pdev); 234 } 235 lockmgr(&dm_pdev_mutex, LK_RELEASE); 236 237 lockuninit(&dm_pdev_mutex); 238 return 0; 239 } 240 /* 241 * This funcion is called from dm_dev_remove_ioctl. 242 * When I'm removing device from list, I have to decrement 243 * reference counter. If reference counter is 0 I will remove 244 * dmp from global list and from device list to. And I will CLOSE 245 * dmp vnode too. 246 */ 247 248 /* 249 * Decrement pdev reference counter if 0 remove it. 250 */ 251 int 252 dm_pdev_decr(dm_pdev_t * dmp) 253 { 254 KKASSERT(dmp != NULL); 255 /* 256 * If this was last reference remove dmp from 257 * global list also. 258 */ 259 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 260 261 if (--dmp->ref_cnt == 0) { 262 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 263 lockmgr(&dm_pdev_mutex, LK_RELEASE); 264 dm_pdev_rem(dmp); 265 return 0; 266 } 267 lockmgr(&dm_pdev_mutex, LK_RELEASE); 268 return 0; 269 } 270 /*static int 271 dm_pdev_dump_list(void) 272 { 273 dm_pdev_t *dmp; 274 275 aprint_verbose("Dumping dm_pdev_list \n"); 276 277 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) { 278 aprint_verbose("dm_pdev_name %s ref_cnt %d list_rf_cnt %d\n", 279 dmp->name, dmp->ref_cnt, dmp->list_ref_cnt); 280 } 281 282 return 0; 283 284 }*/ 285