| 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 <dev/disk/dm/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 | * 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 | *vpp = nd.nl_open_vp; |
| 83 | nd.nl_open_vp = NULL; |
| 84 | nlookup_done(&nd); |
| 85 | |
| 86 | return 0; |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * Since dm can have arbitrary stacking on any number of disks and any dm |
| 91 | * volume is at least stacked onto another disk, we need to adjust the |
| 92 | * dumping offset (which is a raw offset from the beginning of the lowest |
| 93 | * physical disk) taking into account the offset of the underlying device |
| 94 | * which in turn takes into account the offset below it, etc. |
| 95 | * |
| 96 | * This function adjusts the dumping offset that is passed to the next |
| 97 | * dev_ddump() so it is correct for that underlying device. |
| 98 | */ |
| 99 | off_t |
| 100 | dm_pdev_correct_dump_offset(dm_pdev_t *pdev, off_t offset) |
| 101 | { |
| 102 | off_t noffset; |
| 103 | |
| 104 | noffset = pdev->pdev_pinfo.reserved_blocks + |
| 105 | pdev->pdev_pinfo.media_offset / pdev->pdev_pinfo.media_blksize; |
| 106 | noffset *= DEV_BSIZE; |
| 107 | noffset += offset; |
| 108 | |
| 109 | return noffset; |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * Create entry for device with name dev_name and open vnode for it. |
| 114 | * If entry already exists in global SLIST I will only increment |
| 115 | * reference counter. |
| 116 | */ |
| 117 | dm_pdev_t * |
| 118 | dm_pdev_insert(const char *dev_name) |
| 119 | { |
| 120 | dm_pdev_t *dmp; |
| 121 | int error; |
| 122 | |
| 123 | KKASSERT(dev_name != NULL); |
| 124 | |
| 125 | lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); |
| 126 | dmp = dm_pdev_lookup_name(dev_name); |
| 127 | |
| 128 | if (dmp != NULL) { |
| 129 | dmp->ref_cnt++; |
| 130 | aprint_debug("dmp_pdev_insert pdev %s already in tree\n", dev_name); |
| 131 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 132 | return dmp; |
| 133 | } |
| 134 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 135 | |
| 136 | if ((dmp = dm_pdev_alloc(dev_name)) == NULL) |
| 137 | return NULL; |
| 138 | |
| 139 | error = dm_dk_lookup(dev_name, &dmp->pdev_vnode); |
| 140 | if (error) { |
| 141 | aprint_debug("dk_lookup on device: %s failed with error %d!\n", |
| 142 | dev_name, error); |
| 143 | kfree(dmp, M_DM); |
| 144 | return NULL; |
| 145 | } |
| 146 | dmp->ref_cnt = 1; |
| 147 | |
| 148 | /* |
| 149 | * Get us the partinfo from the underlying device, it's needed for |
| 150 | * dumps. |
| 151 | */ |
| 152 | bzero(&dmp->pdev_pinfo, sizeof(dmp->pdev_pinfo)); |
| 153 | error = dev_dioctl(dmp->pdev_vnode->v_rdev, DIOCGPART, |
| 154 | (void *)&dmp->pdev_pinfo, 0, proc0.p_ucred, NULL); |
| 155 | |
| 156 | lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); |
| 157 | SLIST_INSERT_HEAD(&dm_pdev_list, dmp, next_pdev); |
| 158 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 159 | |
| 160 | return dmp; |
| 161 | } |
| 162 | /* |
| 163 | * Initialize pdev subsystem. |
| 164 | */ |
| 165 | int |
| 166 | dm_pdev_init(void) |
| 167 | { |
| 168 | SLIST_INIT(&dm_pdev_list); /* initialize global pdev list */ |
| 169 | lockinit(&dm_pdev_mutex, "dmpdev", 0, LK_CANRECURSE); |
| 170 | |
| 171 | return 0; |
| 172 | } |
| 173 | /* |
| 174 | * Allocat new pdev structure if is not already present and |
| 175 | * set name. |
| 176 | */ |
| 177 | static dm_pdev_t * |
| 178 | dm_pdev_alloc(const char *name) |
| 179 | { |
| 180 | dm_pdev_t *dmp; |
| 181 | |
| 182 | if ((dmp = kmalloc(sizeof(dm_pdev_t), M_DM, M_WAITOK | M_ZERO)) == NULL) |
| 183 | return NULL; |
| 184 | |
| 185 | strlcpy(dmp->name, name, MAX_DEV_NAME); |
| 186 | |
| 187 | dmp->ref_cnt = 0; |
| 188 | dmp->pdev_vnode = NULL; |
| 189 | |
| 190 | return dmp; |
| 191 | } |
| 192 | /* |
| 193 | * Destroy allocated dm_pdev. |
| 194 | */ |
| 195 | static int |
| 196 | dm_pdev_rem(dm_pdev_t * dmp) |
| 197 | { |
| 198 | int err; |
| 199 | |
| 200 | KKASSERT(dmp != NULL); |
| 201 | |
| 202 | if (dmp->pdev_vnode != NULL) { |
| 203 | err = vn_close(dmp->pdev_vnode, FREAD | FWRITE); |
| 204 | if (err != 0) |
| 205 | return err; |
| 206 | } |
| 207 | kfree(dmp, M_DM); |
| 208 | dmp = NULL; |
| 209 | |
| 210 | return 0; |
| 211 | } |
| 212 | /* |
| 213 | * Destroy all existing pdev's in device-mapper. |
| 214 | */ |
| 215 | int |
| 216 | dm_pdev_destroy(void) |
| 217 | { |
| 218 | dm_pdev_t *dm_pdev; |
| 219 | |
| 220 | lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); |
| 221 | while (!SLIST_EMPTY(&dm_pdev_list)) { /* List Deletion. */ |
| 222 | |
| 223 | dm_pdev = SLIST_FIRST(&dm_pdev_list); |
| 224 | |
| 225 | SLIST_REMOVE_HEAD(&dm_pdev_list, next_pdev); |
| 226 | |
| 227 | dm_pdev_rem(dm_pdev); |
| 228 | } |
| 229 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 230 | |
| 231 | lockuninit(&dm_pdev_mutex); |
| 232 | return 0; |
| 233 | } |
| 234 | /* |
| 235 | * This funcion is called from dm_dev_remove_ioctl. |
| 236 | * When I'm removing device from list, I have to decrement |
| 237 | * reference counter. If reference counter is 0 I will remove |
| 238 | * dmp from global list and from device list to. And I will CLOSE |
| 239 | * dmp vnode too. |
| 240 | */ |
| 241 | |
| 242 | /* |
| 243 | * Decrement pdev reference counter if 0 remove it. |
| 244 | */ |
| 245 | int |
| 246 | dm_pdev_decr(dm_pdev_t * dmp) |
| 247 | { |
| 248 | KKASSERT(dmp != NULL); |
| 249 | /* |
| 250 | * If this was last reference remove dmp from |
| 251 | * global list also. |
| 252 | */ |
| 253 | lockmgr(&dm_pdev_mutex, LK_EXCLUSIVE); |
| 254 | |
| 255 | if (--dmp->ref_cnt == 0) { |
| 256 | SLIST_REMOVE(&dm_pdev_list, dmp, dm_pdev, next_pdev); |
| 257 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 258 | dm_pdev_rem(dmp); |
| 259 | return 0; |
| 260 | } |
| 261 | lockmgr(&dm_pdev_mutex, LK_RELEASE); |
| 262 | return 0; |
| 263 | } |