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 *dmp; 60 61 KKASSERT(dm_pdev_name != NULL); 62 63 SLIST_FOREACH(dmp, &dm_pdev_list, next_pdev) { 64 if (strcmp(dm_pdev_name, dmp->name) == 0) 65 return dmp; 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 } 139 140 if ((dmp = dm_pdev_alloc(dev_name)) == NULL) { 141 lockmgr(&dm_pdev_mutex, LK_RELEASE); 142 return NULL; 143 } 144 145 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 dm_pdev_rem(dmp); 150 lockmgr(&dm_pdev_mutex, LK_RELEASE); 151 return NULL; 152 } 153 dmp->ref_cnt = 1; 154 155 /* 156 * Get us the partinfo from the underlying device, it's needed for 157 * dumps. 158 */ 159 bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo)); 160 error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART, 161 (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL, NULL); 162 if (!error) { 163 struct partinfo *dpart = &dmp->pdev_pinfo; 164 aprint_debug("dmp_pdev_insert DIOCGPART " 165 "offset=%ju size=%ju blocks=%ju blksize=%d\n", 166 dpart->media_offset, 167 dpart->media_size, 168 dpart->media_blocks, 169 dpart->media_blksize); 170 } else { 171 kprintf("dmp_pdev_insert DIOCGPART failed %d\n", error); 172 } 173 174 SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); 175 lockmgr(&dm_pdev_mutex, LK_RELEASE); 176 177 return dmp; 178 } 179 180 /* 181 * Allocat new pdev structure if is not already present and 182 * set name. 183 */ 184 static dm_pdev_t * 185 dm_pdev_alloc(const char *name) 186 { 187 dm_pdev_t *dmp; 188 189 if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL) 190 return NULL; 191 192 strlcpy(dmp->name, name, MAX_DEV_NAME); 193 194 dmp->ref_cnt = 0; 195 dmp->pdev_vnode = NULL; 196 197 return dmp; 198 } 199 /* 200 * Destroy allocated dm_pdev. 201 */ 202 static int 203 dm_pdev_rem(dm_pdev_t *dmp) 204 { 205 int err; 206 207 KKASSERT(dmp != NULL); 208 209 if (dmp->pdev_vnode != NULL) { 210 err = vn_close(dmp->pdev_vnode, FREAD | FWRITE, NULL); 211 if (err != 0) 212 return err; 213 } 214 kfree(dmp, M_DM); 215 216 return 0; 217 } 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 } 249 250 /* 251 * Initialize pdev subsystem. 252 */ 253 int 254 dm_pdev_init(void) 255 { 256 SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ 257 lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE); 258 259 return 0; 260 } 261 262 /* 263 * Destroy all existing pdev's in device-mapper. 264 */ 265 int 266 dm_pdev_uninit(void) 267 { 268 dm_pdev_t *dmp; 269 270 lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); 271 272 while ((dmp = SLIST_FIRST(&dm_pdev_list)) != NULL) { 273 SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); 274 dm_pdev_rem(dmp); 275 } 276 KKASSERT(SLIST_EMPTY(&dm_pdev_list)); 277 278 lockmgr(&dm_pdev_mutex, LK_RELEASE); 279 280 lockuninit(&dm_pdev_mutex); 281 return 0; 282 } 283