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 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/spa.h> 29 #include <sys/spa_impl.h> 30 #include <sys/nvpair.h> 31 #include <sys/uio.h> 32 #include <sys/fs/zfs.h> 33 #include <sys/vdev_impl.h> 34 #include <sys/zfs_ioctl.h> 35 #ifdef _KERNEL 36 #include <sys/kobj.h> 37 #endif 38 39 /* 40 * Pool configuration repository. 41 * 42 * The configuration for all pools, in addition to being stored on disk, is 43 * stored in /etc/zfs/zpool.cache as a packed nvlist. The kernel maintains 44 * this list as pools are created, destroyed, or modified. 45 * 46 * We have a single nvlist which holds all the configuration information. When 47 * the module loads, we read this information from the cache and populate the 48 * SPA namespace. This namespace is maintained independently in spa.c. 49 * Whenever the namespace is modified, or the configuration of a pool is 50 * changed, we call spa_config_sync(), which walks through all the active pools 51 * and writes the configuration to disk. 52 */ 53 54 static uint64_t spa_config_generation = 1; 55 56 /* 57 * This can be overridden in userland to preserve an alternate namespace for 58 * userland pools when doing testing. 59 */ 60 const char *spa_config_dir = ZPOOL_CACHE_DIR; 61 62 /* 63 * Called when the module is first loaded, this routine loads the configuration 64 * file into the SPA namespace. It does not actually open or load the pools; it 65 * only populates the namespace. 66 */ 67 void 68 spa_config_load(void) 69 { 70 void *buf = NULL; 71 nvlist_t *nvlist, *child; 72 nvpair_t *nvpair; 73 spa_t *spa; 74 char pathname[128]; 75 struct _buf *file; 76 struct bootstat bst; 77 78 /* 79 * Open the configuration file. 80 */ 81 (void) snprintf(pathname, sizeof (pathname), "%s%s/%s", 82 (rootdir != NULL) ? "./" : "", spa_config_dir, ZPOOL_CACHE_FILE); 83 84 file = kobj_open_file(pathname); 85 if (file == (struct _buf *)-1) 86 return; 87 88 if (kobj_fstat(file->_fd, &bst) != 0) 89 goto out; 90 91 buf = kmem_alloc(bst.st_size, KM_SLEEP); 92 93 /* 94 * Read the nvlist from the file. 95 */ 96 if (kobj_read_file(file, buf, bst.st_size, 0) < 0) 97 goto out; 98 99 /* 100 * Unpack the nvlist. 101 */ 102 if (nvlist_unpack(buf, bst.st_size, &nvlist, KM_SLEEP) != 0) 103 goto out; 104 105 /* 106 * Iterate over all elements in the nvlist, creating a new spa_t for 107 * each one with the specified configuration. 108 */ 109 mutex_enter(&spa_namespace_lock); 110 nvpair = NULL; 111 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 112 113 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 114 continue; 115 116 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0); 117 118 if (spa_lookup(nvpair_name(nvpair)) != NULL) 119 continue; 120 spa = spa_add(nvpair_name(nvpair), NULL); 121 122 /* 123 * We blindly duplicate the configuration here. If it's 124 * invalid, we will catch it when the pool is first opened. 125 */ 126 VERIFY(nvlist_dup(child, &spa->spa_config, 0) == 0); 127 } 128 mutex_exit(&spa_namespace_lock); 129 130 nvlist_free(nvlist); 131 132 out: 133 if (buf != NULL) 134 kmem_free(buf, bst.st_size); 135 136 kobj_close_file(file); 137 } 138 139 /* 140 * Synchronize all pools to disk. This must be called with the namespace lock 141 * held. 142 */ 143 void 144 spa_config_sync(void) 145 { 146 spa_t *spa = NULL; 147 nvlist_t *config; 148 size_t buflen; 149 char *buf; 150 vnode_t *vp; 151 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 152 char pathname[128]; 153 char pathname2[128]; 154 155 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 156 157 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 158 159 /* 160 * Add all known pools to the configuration list, ignoring those with 161 * alternate root paths. 162 */ 163 spa = NULL; 164 while ((spa = spa_next(spa)) != NULL) { 165 mutex_enter(&spa->spa_config_cache_lock); 166 if (spa->spa_config && spa->spa_name && spa->spa_root == NULL) 167 VERIFY(nvlist_add_nvlist(config, spa->spa_name, 168 spa->spa_config) == 0); 169 mutex_exit(&spa->spa_config_cache_lock); 170 } 171 172 /* 173 * Pack the configuration into a buffer. 174 */ 175 VERIFY(nvlist_size(config, &buflen, NV_ENCODE_XDR) == 0); 176 177 buf = kmem_alloc(buflen, KM_SLEEP); 178 179 VERIFY(nvlist_pack(config, &buf, &buflen, NV_ENCODE_XDR, 180 KM_SLEEP) == 0); 181 182 /* 183 * Write the configuration to disk. We need to do the traditional 184 * 'write to temporary file, sync, move over original' to make sure we 185 * always have a consistent view of the data. 186 */ 187 (void) snprintf(pathname, sizeof (pathname), "%s/%s", spa_config_dir, 188 ZPOOL_CACHE_TMP); 189 190 if (vn_open(pathname, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0) != 0) 191 goto out; 192 193 if (vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 194 0, RLIM64_INFINITY, kcred, NULL) == 0 && 195 VOP_FSYNC(vp, FSYNC, kcred) == 0) { 196 (void) snprintf(pathname2, sizeof (pathname2), "%s/%s", 197 spa_config_dir, ZPOOL_CACHE_FILE); 198 (void) vn_rename(pathname, pathname2, UIO_SYSSPACE); 199 } 200 201 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred); 202 VN_RELE(vp); 203 204 out: 205 (void) vn_remove(pathname, UIO_SYSSPACE, RMFILE); 206 spa_config_generation++; 207 208 kmem_free(buf, buflen); 209 nvlist_free(config); 210 } 211 212 /* 213 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 214 * and we don't want to allow the local zone to see all the pools anyway. 215 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 216 * information for all pool visible within the zone. 217 */ 218 nvlist_t * 219 spa_all_configs(uint64_t *generation) 220 { 221 nvlist_t *pools; 222 spa_t *spa; 223 224 if (*generation == spa_config_generation) 225 return (NULL); 226 227 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0); 228 229 spa = NULL; 230 mutex_enter(&spa_namespace_lock); 231 while ((spa = spa_next(spa)) != NULL) { 232 if (INGLOBALZONE(curproc) || 233 zone_dataset_visible(spa_name(spa), NULL)) { 234 mutex_enter(&spa->spa_config_cache_lock); 235 VERIFY(nvlist_add_nvlist(pools, spa_name(spa), 236 spa->spa_config) == 0); 237 mutex_exit(&spa->spa_config_cache_lock); 238 } 239 } 240 mutex_exit(&spa_namespace_lock); 241 242 *generation = spa_config_generation; 243 244 return (pools); 245 } 246 247 void 248 spa_config_set(spa_t *spa, nvlist_t *config) 249 { 250 mutex_enter(&spa->spa_config_cache_lock); 251 if (spa->spa_config != NULL) 252 nvlist_free(spa->spa_config); 253 spa->spa_config = config; 254 mutex_exit(&spa->spa_config_cache_lock); 255 } 256 257 /* 258 * Generate the pool's configuration based on the current in-core state. 259 * We infer whether to generate a complete config or just one top-level config 260 * based on whether vd is the root vdev. 261 */ 262 nvlist_t * 263 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 264 { 265 nvlist_t *config, *nvroot; 266 vdev_t *rvd = spa->spa_root_vdev; 267 268 ASSERT(spa_config_held(spa, RW_READER)); 269 270 if (vd == NULL) 271 vd = rvd; 272 273 /* 274 * If txg is -1, report the current value of spa->spa_config_txg. 275 */ 276 if (txg == -1ULL) 277 txg = spa->spa_config_txg; 278 279 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 280 281 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, 282 spa->spa_uberblock.ub_version) == 0); 283 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, 284 spa_name(spa)) == 0); 285 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, 286 spa_state(spa)) == 0); 287 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, 288 txg) == 0); 289 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, 290 spa_guid(spa)) == 0); 291 292 if (vd != rvd) { 293 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 294 vd->vdev_top->vdev_guid) == 0); 295 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 296 vd->vdev_guid) == 0); 297 vd = vd->vdev_top; /* label contains top config */ 298 } 299 300 nvroot = vdev_config_generate(vd, getstats); 301 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0); 302 nvlist_free(nvroot); 303 304 return (config); 305 } 306 307 /* 308 * Update all disk labels, generate a fresh config based on the current 309 * in-core state, and sync the global config cache. 310 */ 311 void 312 spa_config_update(spa_t *spa, int what) 313 { 314 vdev_t *rvd = spa->spa_root_vdev; 315 uint64_t txg; 316 int c; 317 318 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 319 320 spa_config_enter(spa, RW_WRITER, FTAG); 321 txg = spa_last_synced_txg(spa) + 1; 322 if (what == SPA_CONFIG_UPDATE_POOL) { 323 vdev_config_dirty(rvd); 324 } else { 325 /* 326 * If we have top-level vdevs that were added but have 327 * not yet been prepared for allocation, do that now. 328 * (It's safe now because the config cache is up to date, 329 * so it will be able to translate the new DVAs.) 330 * See comments in spa_vdev_add() for full details. 331 */ 332 for (c = 0; c < rvd->vdev_children; c++) { 333 vdev_t *tvd = rvd->vdev_child[c]; 334 if (tvd->vdev_ms_array == 0) { 335 vdev_init(tvd, txg); 336 vdev_config_dirty(tvd); 337 } 338 } 339 } 340 spa_config_exit(spa, FTAG); 341 342 /* 343 * Wait for the mosconfig to be regenerated and synced. 344 */ 345 txg_wait_synced(spa->spa_dsl_pool, txg); 346 347 /* 348 * Update the global config cache to reflect the new mosconfig. 349 */ 350 spa_config_sync(); 351 352 if (what == SPA_CONFIG_UPDATE_POOL) 353 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 354 } 355