1 /* $NetBSD: dm_pdev.c,v 1.6 2010/01/04 00:19:08 haad Exp $ */ 2 3 /* 4 * Copyright (c) 2010-2011 Alex Hornung <alex@alexhornung.com> 5 * Copyright (c) 2008 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Adam Hamsik. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/types.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 <dev/disk/dm/dm.h> 43 44 SLIST_HEAD(dm_pdevs, dm_pdev) dm_pdev_list; 45 46 static 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 * needs to be called with the dm_pdev_mutex held. 55 */ 56 static dm_pdev_t * 57 dm_pdev_lookup_name(const char *dm_pdev_name) 58 { 59 dm_pdev_t *dm_pdev; 60 61 KKASSERT(dm_pdev_name != NULL); 62 63 SLIST_FOREACH(dm_pdev, &dm_pdev_list, next_pdev) { 64 if (strcmp(dm_pdev_name, dm_pdev->name) == 0) 65 return dm_pdev; 66 } 67 68 return NULL; 69 } 70 71 static int 72 dm_dk_lookup(const char *dev_name, struct vnode **vpp) 73 { 74 struct nlookupdata nd; 75 int error; 76 77 error = nlookup_init(&nd, dev_name, UIO_SYSSPACE, NLC_FOLLOW); 78 if (error) 79 return error; 80 81 error = vn_open(&nd, NULL, FREAD|FWRITE, 0); 82 if (error) { 83 nlookup_done(&nd); 84 return error; 85 } 86 87 *vpp = nd.nl_open_vp; 88 nd.nl_open_vp = NULL; 89 nlookup_done(&nd); 90 91 return 0; 92 } 93 94 /* 95 * Since dm can have arbitrary stacking on any number of disks and any dm 96 * volume is at least stacked onto another disk, we need to adjust the 97 * dumping offset (which is a raw offset from the beginning of the lowest 98 * physical disk) taking into account the offset of the underlying device 99 * which in turn takes into account the offset below it, etc. 100 * 101 * This function adjusts the dumping offset that is passed to the next 102 * dev_ddump() so it is correct for that underlying device. 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 error = dm_dk_lookup(dev_name, &dmp->pdev_vnode); 145 if (error) { 146 aprint_debug("dk_lookup on device: %s failed with error %d!\n", 147 dev_name, error); 148 kfree(dmp, M_DM); 149 return NULL; 150 } 151 dmp->ref_cnt = 1; 152 153 /* 154 * Get us the partinfo from the underlying device, it's needed for 155 * dumps. 156 */ 157 bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo)); 158 error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART, 159 (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL, NULL); 160 161 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 162 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 163 lockmgr(&dm_pdev_mutex, LK_RELEASE); 164 165 return dmp; 166 } 167 168 /* 169 * Allocat new pdev structure if is not already present and 170 * set name. 171 */ 172 static dm_pdev_t * 173 dm_pdev_alloc(const char *name) 174 { 175 dm_pdev_t *dmp; 176 177 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL) 178 return NULL; 179 180 strlcpy(dmp->name, name, MAX_DEV_NAME); 181 182 dmp->ref_cnt = 0; 183 dmp->pdev_vnode = NULL; 184 185 return dmp; 186 } 187 /* 188 * Destroy allocated dm_pdev. 189 */ 190 static int 191 dm_pdev_rem(dm_pdev_t * dmp) 192 { 193 int err; 194 195 KKASSERT(dmp != NULL); 196 197 if (dmp->pdev_vnode != NULL) { 198 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, NULL); 199 if (err != 0) 200 return err; 201 } 202 kfree(dmp, M_DM); 203 dmp = NULL; 204 205 return 0; 206 } 207 208 /* 209 * This funcion is called from dm_dev_remove_ioctl. 210 * When I'm removing device from list, I have to decrement 211 * reference counter. If reference counter is 0 I will remove 212 * dmp from global list and from device list to. And I will CLOSE 213 * dmp vnode too. 214 */ 215 216 /* 217 * Decrement pdev reference counter if 0 remove it. 218 */ 219 int 220 dm_pdev_decr(dm_pdev_t * dmp) 221 { 222 KKASSERT(dmp != NULL); 223 /* 224 * If this was last reference remove dmp from 225 * global list also. 226 */ 227 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 228 229 if (--dmp->ref_cnt == 0) { 230 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 231 lockmgr(&dm_pdev_mutex, LK_RELEASE); 232 dm_pdev_rem(dmp); 233 return 0; 234 } 235 lockmgr(&dm_pdev_mutex, LK_RELEASE); 236 return 0; 237 } 238 239 /* 240 * Initialize pdev subsystem. 241 */ 242 int 243 dm_pdev_init(void) 244 { 245 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 246 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE); 247 248 return 0; 249 } 250 251 /* 252 * Destroy all existing pdev's in device-mapper. 253 */ 254 int 255 dm_pdev_uninit(void) 256 { 257 dm_pdev_t *dm_pdev; 258 259 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 260 while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ 261 262 dm_pdev = SLIST_FIRST(&dm_pdev_list); 263 264 SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); 265 266 dm_pdev_rem(dm_pdev); 267 } 268 lockmgr(&dm_pdev_mutex, LK_RELEASE); 269 270 lockuninit(&dm_pdev_mutex); 271 return 0; 272 } 273