1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/spa.h> 30 #include <sys/spa_impl.h> 31 #include <sys/nvpair.h> 32 #include <sys/uio.h> 33 #include <sys/fs/zfs.h> 34 #include <sys/vdev_impl.h> 35 #include <sys/zfs_ioctl.h> 36 #ifdef _KERNEL 37 #include <sys/kobj.h> 38 #endif 39 40 /* 41 * Pool configuration repository. 42 * 43 * The configuration for all pools, in addition to being stored on disk, is 44 * stored in /etc/zfs/zpool.cache as a packed nvlist. The kernel maintains 45 * this list as pools are created, destroyed, or modified. 46 * 47 * We have a single nvlist which holds all the configuration information. When 48 * the module loads, we read this information from the cache and populate the 49 * SPA namespace. This namespace is maintained independently in spa.c. 50 * Whenever the namespace is modified, or the configuration of a pool is 51 * changed, we call spa_config_sync(), which walks through all the active pools 52 * and writes the configuration to disk. 53 */ 54 55 static uint64_t spa_config_generation = 1; 56 57 /* 58 * This can be overridden in userland to preserve an alternate namespace for 59 * userland pools when doing testing. 60 */ 61 const char *spa_config_dir = ZPOOL_CACHE_DIR; 62 63 /* 64 * Called when the module is first loaded, this routine loads the configuration 65 * file into the SPA namespace. It does not actually open or load the pools; it 66 * only populates the namespace. 67 */ 68 void 69 spa_config_load(void) 70 { 71 void *buf = NULL; 72 nvlist_t *nvlist, *child; 73 nvpair_t *nvpair; 74 spa_t *spa; 75 char pathname[128]; 76 struct _buf *file; 77 uint64_t fsize; 78 79 /* 80 * Open the configuration file. 81 */ 82 (void) snprintf(pathname, sizeof (pathname), "%s%s/%s", 83 (rootdir != NULL) ? "./" : "", spa_config_dir, ZPOOL_CACHE_FILE); 84 85 file = kobj_open_file(pathname); 86 if (file == (struct _buf *)-1) 87 return; 88 89 if (kobj_get_filesize(file, &fsize) != 0) 90 goto out; 91 92 buf = kmem_alloc(fsize, KM_SLEEP); 93 94 /* 95 * Read the nvlist from the file. 96 */ 97 if (kobj_read_file(file, buf, fsize, 0) < 0) 98 goto out; 99 100 /* 101 * Unpack the nvlist. 102 */ 103 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 104 goto out; 105 106 /* 107 * Iterate over all elements in the nvlist, creating a new spa_t for 108 * each one with the specified configuration. 109 */ 110 mutex_enter(&spa_namespace_lock); 111 nvpair = NULL; 112 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 113 114 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 115 continue; 116 117 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0); 118 119 if (spa_lookup(nvpair_name(nvpair)) != NULL) 120 continue; 121 spa = spa_add(nvpair_name(nvpair), NULL); 122 123 /* 124 * We blindly duplicate the configuration here. If it's 125 * invalid, we will catch it when the pool is first opened. 126 */ 127 VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0); 128 } 129 mutex_exit(&spa_namespace_lock); 130 131 nvlist_free(nvlist); 132 133 out: 134 if (buf != NULL) 135 kmem_free(buf, fsize); 136 137 kobj_close_file(file); 138 } 139 140 /* 141 * Synchronize all pools to disk. This must be called with the namespace lock 142 * held. 143 */ 144 void 145 spa_config_sync(void) 146 { 147 spa_t *spa = NULL; 148 nvlist_t *config; 149 size_t buflen; 150 char *buf; 151 vnode_t *vp; 152 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 153 char pathname[128]; 154 char pathname2[128]; 155 156 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 157 158 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 159 160 /* 161 * Add all known pools to the configuration list, ignoring those with 162 * alternate root paths. 163 */ 164 spa = NULL; 165 while ((spa = spa_next(spa)) != NULL) { 166 mutex_enter(&spa->spa_config_cache_lock); 167 if (spa->spa_config && spa->spa_name && spa->spa_root == NULL) 168 VERIFY(nvlist_add_nvlist(config, spa->spa_name, 169 spa->spa_config) == 0); 170 mutex_exit(&spa->spa_config_cache_lock); 171 } 172 173 /* 174 * Pack the configuration into a buffer. 175 */ 176 VERIFY(nvlist_size(config, &buflen, NV_ENCODE_XDR) == 0); 177 178 buf = kmem_alloc(buflen, KM_SLEEP); 179 180 VERIFY(nvlist_pack(config, &buf, &buflen, NV_ENCODE_XDR, 181 KM_SLEEP) == 0); 182 183 /* 184 * Write the configuration to disk. We need to do the traditional 185 * 'write to temporary file, sync, move over original' to make sure we 186 * always have a consistent view of the data. 187 */ 188 (void) snprintf(pathname, sizeof (pathname), "%s/%s", spa_config_dir, 189 ZPOOL_CACHE_TMP); 190 191 if (vn_open(pathname, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) != 0) 192 goto out; 193 194 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 195 0, RLIM64_INFINITY, kcred, NULL) == 0 && 196 VOP_FSYNC(vp, FSYNC, kcred) == 0) { 197 (void) snprintf(pathname2, sizeof (pathname2), "%s/%s", 198 spa_config_dir, ZPOOL_CACHE_FILE); 199 (void) vn_rename(pathname, pathname2, UIO_SYSSPACE); 200 } 201 202 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred); 203 VN_RELE(vp); 204 205 out: 206 (void) vn_remove(pathname, UIO_SYSSPACE, RMFILE); 207 spa_config_generation++; 208 209 kmem_free(buf, buflen); 210 nvlist_free(config); 211 } 212 213 /* 214 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 215 * and we don't want to allow the local zone to see all the pools anyway. 216 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 217 * information for all pool visible within the zone. 218 */ 219 nvlist_t * 220 spa_all_configs(uint64_t *generation) 221 { 222 nvlist_t *pools; 223 spa_t *spa; 224 225 if (*generation == spa_config_generation) 226 return (NULL); 227 228 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0); 229 230 spa = NULL; 231 mutex_enter(&spa_namespace_lock); 232 while ((spa = spa_next(spa)) != NULL) { 233 if (INGLOBALZONE(curproc) || 234 zone_dataset_visible(spa_name(spa), NULL)) { 235 mutex_enter(&spa->spa_config_cache_lock); 236 VERIFY(nvlist_add_nvlist(pools, spa_name(spa), 237 spa->spa_config) == 0); 238 mutex_exit(&spa->spa_config_cache_lock); 239 } 240 } 241 mutex_exit(&spa_namespace_lock); 242 243 *generation = spa_config_generation; 244 245 return (pools); 246 } 247 248 void 249 spa_config_set(spa_t *spa, nvlist_t *config) 250 { 251 mutex_enter(&spa->spa_config_cache_lock); 252 if (spa->spa_config != NULL) 253 nvlist_free(spa->spa_config); 254 spa->spa_config = config; 255 mutex_exit(&spa->spa_config_cache_lock); 256 } 257 258 /* 259 * Generate the pool's configuration based on the current in-core state. 260 * We infer whether to generate a complete config or just one top-level config 261 * based on whether vd is the root vdev. 262 */ 263 nvlist_t * 264 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 265 { 266 nvlist_t *config, *nvroot; 267 vdev_t *rvd = spa->spa_root_vdev; 268 269 ASSERT(spa_config_held(spa, RW_READER)); 270 271 if (vd == NULL) 272 vd = rvd; 273 274 /* 275 * If txg is -1, report the current value of spa->spa_config_txg. 276 */ 277 if (txg == -1ULL) 278 txg = spa->spa_config_txg; 279 280 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 281 282 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, 283 spa_version(spa)) == 0); 284 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, 285 spa_name(spa)) == 0); 286 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, 287 spa_state(spa)) == 0); 288 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, 289 txg) == 0); 290 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, 291 spa_guid(spa)) == 0); 292 293 if (vd != rvd) { 294 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 295 vd->vdev_top->vdev_guid) == 0); 296 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 297 vd->vdev_guid) == 0); 298 if (vd->vdev_isspare) 299 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE, 300 1ULL) == 0); 301 vd = vd->vdev_top; /* label contains top config */ 302 } 303 304 nvroot = vdev_config_generate(spa, vd, getstats, B_FALSE); 305 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0); 306 nvlist_free(nvroot); 307 308 return (config); 309 } 310 311 /* 312 * Update all disk labels, generate a fresh config based on the current 313 * in-core state, and sync the global config cache. 314 */ 315 void 316 spa_config_update(spa_t *spa, int what) 317 { 318 vdev_t *rvd = spa->spa_root_vdev; 319 uint64_t txg; 320 int c; 321 322 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 323 324 spa_config_enter(spa, RW_WRITER, FTAG); 325 txg = spa_last_synced_txg(spa) + 1; 326 if (what == SPA_CONFIG_UPDATE_POOL) { 327 vdev_config_dirty(rvd); 328 } else { 329 /* 330 * If we have top-level vdevs that were added but have 331 * not yet been prepared for allocation, do that now. 332 * (It's safe now because the config cache is up to date, 333 * so it will be able to translate the new DVAs.) 334 * See comments in spa_vdev_add() for full details. 335 */ 336 for (c = 0; c < rvd->vdev_children; c++) { 337 vdev_t *tvd = rvd->vdev_child[c]; 338 if (tvd->vdev_ms_array == 0) { 339 vdev_init(tvd, txg); 340 vdev_config_dirty(tvd); 341 } 342 } 343 } 344 spa_config_exit(spa, FTAG); 345 346 /* 347 * Wait for the mosconfig to be regenerated and synced. 348 */ 349 txg_wait_synced(spa->spa_dsl_pool, txg); 350 351 /* 352 * Update the global config cache to reflect the new mosconfig. 353 */ 354 spa_config_sync(); 355 356 if (what == SPA_CONFIG_UPDATE_POOL) 357 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 358 } 359