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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2012, 2020 by Delphix. All rights reserved. 25 * Copyright (c) 2017, Intel Corporation. 26 * Copyright 2020 Joyent, Inc. 27 */ 28 29 /* 30 * Virtual Device Labels 31 * --------------------- 32 * 33 * The vdev label serves several distinct purposes: 34 * 35 * 1. Uniquely identify this device as part of a ZFS pool and confirm its 36 * identity within the pool. 37 * 38 * 2. Verify that all the devices given in a configuration are present 39 * within the pool. 40 * 41 * 3. Determine the uberblock for the pool. 42 * 43 * 4. In case of an import operation, determine the configuration of the 44 * toplevel vdev of which it is a part. 45 * 46 * 5. If an import operation cannot find all the devices in the pool, 47 * provide enough information to the administrator to determine which 48 * devices are missing. 49 * 50 * It is important to note that while the kernel is responsible for writing the 51 * label, it only consumes the information in the first three cases. The 52 * latter information is only consumed in userland when determining the 53 * configuration to import a pool. 54 * 55 * 56 * Label Organization 57 * ------------------ 58 * 59 * Before describing the contents of the label, it's important to understand how 60 * the labels are written and updated with respect to the uberblock. 61 * 62 * When the pool configuration is altered, either because it was newly created 63 * or a device was added, we want to update all the labels such that we can deal 64 * with fatal failure at any point. To this end, each disk has two labels which 65 * are updated before and after the uberblock is synced. Assuming we have 66 * labels and an uberblock with the following transaction groups: 67 * 68 * L1 UB L2 69 * +------+ +------+ +------+ 70 * | | | | | | 71 * | t10 | | t10 | | t10 | 72 * | | | | | | 73 * +------+ +------+ +------+ 74 * 75 * In this stable state, the labels and the uberblock were all updated within 76 * the same transaction group (10). Each label is mirrored and checksummed, so 77 * that we can detect when we fail partway through writing the label. 78 * 79 * In order to identify which labels are valid, the labels are written in the 80 * following manner: 81 * 82 * 1. For each vdev, update 'L1' to the new label 83 * 2. Update the uberblock 84 * 3. For each vdev, update 'L2' to the new label 85 * 86 * Given arbitrary failure, we can determine the correct label to use based on 87 * the transaction group. If we fail after updating L1 but before updating the 88 * UB, we will notice that L1's transaction group is greater than the uberblock, 89 * so L2 must be valid. If we fail after writing the uberblock but before 90 * writing L2, we will notice that L2's transaction group is less than L1, and 91 * therefore L1 is valid. 92 * 93 * Another added complexity is that not every label is updated when the config 94 * is synced. If we add a single device, we do not want to have to re-write 95 * every label for every device in the pool. This means that both L1 and L2 may 96 * be older than the pool uberblock, because the necessary information is stored 97 * on another vdev. 98 * 99 * 100 * On-disk Format 101 * -------------- 102 * 103 * The vdev label consists of two distinct parts, and is wrapped within the 104 * vdev_label_t structure. The label includes 8k of padding to permit legacy 105 * VTOC disk labels, but is otherwise ignored. 106 * 107 * The first half of the label is a packed nvlist which contains pool wide 108 * properties, per-vdev properties, and configuration information. It is 109 * described in more detail below. 110 * 111 * The latter half of the label consists of a redundant array of uberblocks. 112 * These uberblocks are updated whenever a transaction group is committed, 113 * or when the configuration is updated. When a pool is loaded, we scan each 114 * vdev for the 'best' uberblock. 115 * 116 * 117 * Configuration Information 118 * ------------------------- 119 * 120 * The nvlist describing the pool and vdev contains the following elements: 121 * 122 * version ZFS on-disk version 123 * name Pool name 124 * state Pool state 125 * txg Transaction group in which this label was written 126 * pool_guid Unique identifier for this pool 127 * vdev_tree An nvlist describing vdev tree. 128 * features_for_read 129 * An nvlist of the features necessary for reading the MOS. 130 * 131 * Each leaf device label also contains the following: 132 * 133 * top_guid Unique ID for top-level vdev in which this is contained 134 * guid Unique ID for the leaf vdev 135 * 136 * The 'vs' configuration follows the format described in 'spa_config.c'. 137 */ 138 139 #include <sys/zfs_context.h> 140 #include <sys/spa.h> 141 #include <sys/spa_impl.h> 142 #include <sys/dmu.h> 143 #include <sys/zap.h> 144 #include <sys/vdev.h> 145 #include <sys/vdev_impl.h> 146 #include <sys/uberblock_impl.h> 147 #include <sys/metaslab.h> 148 #include <sys/metaslab_impl.h> 149 #include <sys/zio.h> 150 #include <sys/dsl_scan.h> 151 #include <sys/abd.h> 152 #include <sys/fs/zfs.h> 153 #include <sys/byteorder.h> 154 #include <sys/zfs_bootenv.h> 155 156 /* 157 * Basic routines to read and write from a vdev label. 158 * Used throughout the rest of this file. 159 */ 160 uint64_t 161 vdev_label_offset(uint64_t psize, int l, uint64_t offset) 162 { 163 ASSERT(offset < sizeof (vdev_label_t)); 164 ASSERT(P2PHASE_TYPED(psize, sizeof (vdev_label_t), uint64_t) == 0); 165 166 return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 167 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); 168 } 169 170 /* 171 * Returns back the vdev label associated with the passed in offset. 172 */ 173 int 174 vdev_label_number(uint64_t psize, uint64_t offset) 175 { 176 int l; 177 178 if (offset >= psize - VDEV_LABEL_END_SIZE) { 179 offset -= psize - VDEV_LABEL_END_SIZE; 180 offset += (VDEV_LABELS / 2) * sizeof (vdev_label_t); 181 } 182 l = offset / sizeof (vdev_label_t); 183 return (l < VDEV_LABELS ? l : -1); 184 } 185 186 static void 187 vdev_label_read(zio_t *zio, vdev_t *vd, int l, abd_t *buf, uint64_t offset, 188 uint64_t size, zio_done_func_t *done, void *private, int flags) 189 { 190 ASSERT( 191 spa_config_held(zio->io_spa, SCL_STATE, RW_READER) == SCL_STATE || 192 spa_config_held(zio->io_spa, SCL_STATE, RW_WRITER) == SCL_STATE); 193 ASSERT(flags & ZIO_FLAG_CONFIG_WRITER); 194 195 zio_nowait(zio_read_phys(zio, vd, 196 vdev_label_offset(vd->vdev_psize, l, offset), 197 size, buf, ZIO_CHECKSUM_LABEL, done, private, 198 ZIO_PRIORITY_SYNC_READ, flags, B_TRUE)); 199 } 200 201 void 202 vdev_label_write(zio_t *zio, vdev_t *vd, int l, abd_t *buf, uint64_t offset, 203 uint64_t size, zio_done_func_t *done, void *private, int flags) 204 { 205 ASSERT( 206 spa_config_held(zio->io_spa, SCL_STATE, RW_READER) == SCL_STATE || 207 spa_config_held(zio->io_spa, SCL_STATE, RW_WRITER) == SCL_STATE); 208 ASSERT(flags & ZIO_FLAG_CONFIG_WRITER); 209 210 zio_nowait(zio_write_phys(zio, vd, 211 vdev_label_offset(vd->vdev_psize, l, offset), 212 size, buf, ZIO_CHECKSUM_LABEL, done, private, 213 ZIO_PRIORITY_SYNC_WRITE, flags, B_TRUE)); 214 } 215 216 /* 217 * Generate the nvlist representing this vdev's stats 218 */ 219 void 220 vdev_config_generate_stats(vdev_t *vd, nvlist_t *nv) 221 { 222 nvlist_t *nvx; 223 vdev_stat_t *vs; 224 vdev_stat_ex_t *vsx; 225 226 vs = kmem_alloc(sizeof (*vs), KM_SLEEP); 227 vsx = kmem_alloc(sizeof (*vsx), KM_SLEEP); 228 229 vdev_get_stats_ex(vd, vs, vsx); 230 fnvlist_add_uint64_array(nv, ZPOOL_CONFIG_VDEV_STATS, 231 (uint64_t *)vs, sizeof (*vs) / sizeof (uint64_t)); 232 233 /* 234 * Add extended stats into a special extended stats nvlist. This keeps 235 * all the extended stats nicely grouped together. The extended stats 236 * nvlist is then added to the main nvlist. 237 */ 238 nvx = fnvlist_alloc(); 239 240 /* ZIOs in flight to disk */ 241 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_ACTIVE_QUEUE, 242 vsx->vsx_active_queue[ZIO_PRIORITY_SYNC_READ]); 243 244 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_ACTIVE_QUEUE, 245 vsx->vsx_active_queue[ZIO_PRIORITY_SYNC_WRITE]); 246 247 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_ACTIVE_QUEUE, 248 vsx->vsx_active_queue[ZIO_PRIORITY_ASYNC_READ]); 249 250 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_ACTIVE_QUEUE, 251 vsx->vsx_active_queue[ZIO_PRIORITY_ASYNC_WRITE]); 252 253 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SCRUB_ACTIVE_QUEUE, 254 vsx->vsx_active_queue[ZIO_PRIORITY_SCRUB]); 255 256 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_TRIM_ACTIVE_QUEUE, 257 vsx->vsx_active_queue[ZIO_PRIORITY_TRIM]); 258 259 /* ZIOs pending */ 260 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_PEND_QUEUE, 261 vsx->vsx_pend_queue[ZIO_PRIORITY_SYNC_READ]); 262 263 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_PEND_QUEUE, 264 vsx->vsx_pend_queue[ZIO_PRIORITY_SYNC_WRITE]); 265 266 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_PEND_QUEUE, 267 vsx->vsx_pend_queue[ZIO_PRIORITY_ASYNC_READ]); 268 269 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_PEND_QUEUE, 270 vsx->vsx_pend_queue[ZIO_PRIORITY_ASYNC_WRITE]); 271 272 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SCRUB_PEND_QUEUE, 273 vsx->vsx_pend_queue[ZIO_PRIORITY_SCRUB]); 274 275 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_TRIM_PEND_QUEUE, 276 vsx->vsx_pend_queue[ZIO_PRIORITY_TRIM]); 277 278 /* Histograms */ 279 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TOT_R_LAT_HISTO, 280 vsx->vsx_total_histo[ZIO_TYPE_READ], 281 ARRAY_SIZE(vsx->vsx_total_histo[ZIO_TYPE_READ])); 282 283 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TOT_W_LAT_HISTO, 284 vsx->vsx_total_histo[ZIO_TYPE_WRITE], 285 ARRAY_SIZE(vsx->vsx_total_histo[ZIO_TYPE_WRITE])); 286 287 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_DISK_R_LAT_HISTO, 288 vsx->vsx_disk_histo[ZIO_TYPE_READ], 289 ARRAY_SIZE(vsx->vsx_disk_histo[ZIO_TYPE_READ])); 290 291 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_DISK_W_LAT_HISTO, 292 vsx->vsx_disk_histo[ZIO_TYPE_WRITE], 293 ARRAY_SIZE(vsx->vsx_disk_histo[ZIO_TYPE_WRITE])); 294 295 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_R_LAT_HISTO, 296 vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_READ], 297 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_READ])); 298 299 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_W_LAT_HISTO, 300 vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_WRITE], 301 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SYNC_WRITE])); 302 303 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_R_LAT_HISTO, 304 vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_READ], 305 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_READ])); 306 307 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_W_LAT_HISTO, 308 vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_WRITE], 309 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_ASYNC_WRITE])); 310 311 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SCRUB_LAT_HISTO, 312 vsx->vsx_queue_histo[ZIO_PRIORITY_SCRUB], 313 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_SCRUB])); 314 315 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_TRIM_LAT_HISTO, 316 vsx->vsx_queue_histo[ZIO_PRIORITY_TRIM], 317 ARRAY_SIZE(vsx->vsx_queue_histo[ZIO_PRIORITY_TRIM])); 318 319 /* Request sizes */ 320 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_IND_R_HISTO, 321 vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_READ], 322 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_READ])); 323 324 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_IND_W_HISTO, 325 vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_WRITE], 326 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SYNC_WRITE])); 327 328 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_IND_R_HISTO, 329 vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_READ], 330 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_READ])); 331 332 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_IND_W_HISTO, 333 vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_WRITE], 334 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_ASYNC_WRITE])); 335 336 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_IND_SCRUB_HISTO, 337 vsx->vsx_ind_histo[ZIO_PRIORITY_SCRUB], 338 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_SCRUB])); 339 340 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_IND_TRIM_HISTO, 341 vsx->vsx_ind_histo[ZIO_PRIORITY_TRIM], 342 ARRAY_SIZE(vsx->vsx_ind_histo[ZIO_PRIORITY_TRIM])); 343 344 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_AGG_R_HISTO, 345 vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_READ], 346 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_READ])); 347 348 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_SYNC_AGG_W_HISTO, 349 vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_WRITE], 350 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SYNC_WRITE])); 351 352 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_AGG_R_HISTO, 353 vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_READ], 354 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_READ])); 355 356 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_ASYNC_AGG_W_HISTO, 357 vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_WRITE], 358 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_ASYNC_WRITE])); 359 360 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_AGG_SCRUB_HISTO, 361 vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB], 362 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_SCRUB])); 363 364 fnvlist_add_uint64_array(nvx, ZPOOL_CONFIG_VDEV_AGG_TRIM_HISTO, 365 vsx->vsx_agg_histo[ZIO_PRIORITY_TRIM], 366 ARRAY_SIZE(vsx->vsx_agg_histo[ZIO_PRIORITY_TRIM])); 367 368 /* IO delays */ 369 fnvlist_add_uint64(nvx, ZPOOL_CONFIG_VDEV_SLOW_IOS, vs->vs_slow_ios); 370 371 /* Add extended stats nvlist to main nvlist */ 372 fnvlist_add_nvlist(nv, ZPOOL_CONFIG_VDEV_STATS_EX, nvx); 373 374 nvlist_free(nvx); 375 kmem_free(vs, sizeof (*vs)); 376 kmem_free(vsx, sizeof (*vsx)); 377 } 378 379 static void 380 root_vdev_actions_getprogress(vdev_t *vd, nvlist_t *nvl) 381 { 382 spa_t *spa = vd->vdev_spa; 383 384 if (vd != spa->spa_root_vdev) 385 return; 386 387 /* provide either current or previous scan information */ 388 pool_scan_stat_t ps; 389 if (spa_scan_get_stats(spa, &ps) == 0) { 390 fnvlist_add_uint64_array(nvl, 391 ZPOOL_CONFIG_SCAN_STATS, (uint64_t *)&ps, 392 sizeof (pool_scan_stat_t) / sizeof (uint64_t)); 393 } 394 395 pool_removal_stat_t prs; 396 if (spa_removal_get_stats(spa, &prs) == 0) { 397 fnvlist_add_uint64_array(nvl, 398 ZPOOL_CONFIG_REMOVAL_STATS, (uint64_t *)&prs, 399 sizeof (prs) / sizeof (uint64_t)); 400 } 401 402 pool_checkpoint_stat_t pcs; 403 if (spa_checkpoint_get_stats(spa, &pcs) == 0) { 404 fnvlist_add_uint64_array(nvl, 405 ZPOOL_CONFIG_CHECKPOINT_STATS, (uint64_t *)&pcs, 406 sizeof (pcs) / sizeof (uint64_t)); 407 } 408 } 409 410 /* 411 * Generate the nvlist representing this vdev's config. 412 */ 413 nvlist_t * 414 vdev_config_generate(spa_t *spa, vdev_t *vd, boolean_t getstats, 415 vdev_config_flag_t flags) 416 { 417 nvlist_t *nv = NULL; 418 vdev_indirect_config_t *vic = &vd->vdev_indirect_config; 419 420 nv = fnvlist_alloc(); 421 422 fnvlist_add_string(nv, ZPOOL_CONFIG_TYPE, vd->vdev_ops->vdev_op_type); 423 if (!(flags & (VDEV_CONFIG_SPARE | VDEV_CONFIG_L2CACHE))) 424 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ID, vd->vdev_id); 425 fnvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, vd->vdev_guid); 426 427 if (vd->vdev_path != NULL) 428 fnvlist_add_string(nv, ZPOOL_CONFIG_PATH, vd->vdev_path); 429 430 if (vd->vdev_devid != NULL) 431 fnvlist_add_string(nv, ZPOOL_CONFIG_DEVID, vd->vdev_devid); 432 433 if (vd->vdev_physpath != NULL) 434 fnvlist_add_string(nv, ZPOOL_CONFIG_PHYS_PATH, 435 vd->vdev_physpath); 436 437 if (vd->vdev_fru != NULL) 438 fnvlist_add_string(nv, ZPOOL_CONFIG_FRU, vd->vdev_fru); 439 440 if (vd->vdev_nparity != 0) { 441 ASSERT(strcmp(vd->vdev_ops->vdev_op_type, 442 VDEV_TYPE_RAIDZ) == 0); 443 444 /* 445 * Make sure someone hasn't managed to sneak a fancy new vdev 446 * into a crufty old storage pool. 447 */ 448 ASSERT(vd->vdev_nparity == 1 || 449 (vd->vdev_nparity <= 2 && 450 spa_version(spa) >= SPA_VERSION_RAIDZ2) || 451 (vd->vdev_nparity <= 3 && 452 spa_version(spa) >= SPA_VERSION_RAIDZ3)); 453 454 /* 455 * Note that we'll add the nparity tag even on storage pools 456 * that only support a single parity device -- older software 457 * will just ignore it. 458 */ 459 fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vd->vdev_nparity); 460 } 461 462 if (vd->vdev_wholedisk != -1ULL) 463 fnvlist_add_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, 464 vd->vdev_wholedisk); 465 466 if (vd->vdev_not_present && !(flags & VDEV_CONFIG_MISSING)) 467 fnvlist_add_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, 1); 468 469 if (vd->vdev_isspare) 470 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1); 471 472 if (!(flags & (VDEV_CONFIG_SPARE | VDEV_CONFIG_L2CACHE)) && 473 vd == vd->vdev_top) { 474 fnvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY, 475 vd->vdev_ms_array); 476 fnvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT, 477 vd->vdev_ms_shift); 478 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ASHIFT, vd->vdev_ashift); 479 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ASIZE, 480 vd->vdev_asize); 481 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_LOG, vd->vdev_islog); 482 if (vd->vdev_removing) { 483 fnvlist_add_uint64(nv, ZPOOL_CONFIG_REMOVING, 484 vd->vdev_removing); 485 } 486 487 /* zpool command expects alloc class data */ 488 if (getstats && vd->vdev_alloc_bias != VDEV_BIAS_NONE) { 489 const char *bias = NULL; 490 491 switch (vd->vdev_alloc_bias) { 492 case VDEV_BIAS_LOG: 493 bias = VDEV_ALLOC_BIAS_LOG; 494 break; 495 case VDEV_BIAS_SPECIAL: 496 bias = VDEV_ALLOC_BIAS_SPECIAL; 497 break; 498 case VDEV_BIAS_DEDUP: 499 bias = VDEV_ALLOC_BIAS_DEDUP; 500 break; 501 default: 502 ASSERT3U(vd->vdev_alloc_bias, ==, 503 VDEV_BIAS_NONE); 504 } 505 fnvlist_add_string(nv, ZPOOL_CONFIG_ALLOCATION_BIAS, 506 bias); 507 } 508 } 509 510 if (vd->vdev_dtl_sm != NULL) { 511 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DTL, 512 space_map_object(vd->vdev_dtl_sm)); 513 } 514 515 if (vic->vic_mapping_object != 0) { 516 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_OBJECT, 517 vic->vic_mapping_object); 518 } 519 520 if (vic->vic_births_object != 0) { 521 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_BIRTHS, 522 vic->vic_births_object); 523 } 524 525 if (vic->vic_prev_indirect_vdev != UINT64_MAX) { 526 fnvlist_add_uint64(nv, ZPOOL_CONFIG_PREV_INDIRECT_VDEV, 527 vic->vic_prev_indirect_vdev); 528 } 529 530 if (vd->vdev_crtxg) 531 fnvlist_add_uint64(nv, ZPOOL_CONFIG_CREATE_TXG, vd->vdev_crtxg); 532 533 if (flags & VDEV_CONFIG_MOS) { 534 if (vd->vdev_leaf_zap != 0) { 535 ASSERT(vd->vdev_ops->vdev_op_leaf); 536 fnvlist_add_uint64(nv, ZPOOL_CONFIG_VDEV_LEAF_ZAP, 537 vd->vdev_leaf_zap); 538 } 539 540 if (vd->vdev_top_zap != 0) { 541 ASSERT(vd == vd->vdev_top); 542 fnvlist_add_uint64(nv, ZPOOL_CONFIG_VDEV_TOP_ZAP, 543 vd->vdev_top_zap); 544 } 545 546 if (vd->vdev_resilver_deferred) { 547 ASSERT(vd->vdev_ops->vdev_op_leaf); 548 ASSERT(spa->spa_resilver_deferred); 549 fnvlist_add_boolean(nv, ZPOOL_CONFIG_RESILVER_DEFER); 550 } 551 } 552 553 if (getstats) { 554 vdev_config_generate_stats(vd, nv); 555 556 root_vdev_actions_getprogress(vd, nv); 557 558 /* 559 * Note: this can be called from open context 560 * (spa_get_stats()), so we need the rwlock to prevent 561 * the mapping from being changed by condensing. 562 */ 563 rw_enter(&vd->vdev_indirect_rwlock, RW_READER); 564 if (vd->vdev_indirect_mapping != NULL) { 565 ASSERT(vd->vdev_indirect_births != NULL); 566 vdev_indirect_mapping_t *vim = 567 vd->vdev_indirect_mapping; 568 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_SIZE, 569 vdev_indirect_mapping_size(vim)); 570 } 571 rw_exit(&vd->vdev_indirect_rwlock); 572 if (vd->vdev_mg != NULL && 573 vd->vdev_mg->mg_fragmentation != ZFS_FRAG_INVALID) { 574 /* 575 * Compute approximately how much memory would be used 576 * for the indirect mapping if this device were to 577 * be removed. 578 * 579 * Note: If the frag metric is invalid, then not 580 * enough metaslabs have been converted to have 581 * histograms. 582 */ 583 uint64_t seg_count = 0; 584 uint64_t to_alloc = vd->vdev_stat.vs_alloc; 585 586 /* 587 * There are the same number of allocated segments 588 * as free segments, so we will have at least one 589 * entry per free segment. However, small free 590 * segments (smaller than vdev_removal_max_span) 591 * will be combined with adjacent allocated segments 592 * as a single mapping. 593 */ 594 for (int i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++) { 595 if (1ULL << (i + 1) < vdev_removal_max_span) { 596 to_alloc += 597 vd->vdev_mg->mg_histogram[i] << 598 i + 1; 599 } else { 600 seg_count += 601 vd->vdev_mg->mg_histogram[i]; 602 } 603 } 604 605 /* 606 * The maximum length of a mapping is 607 * zfs_remove_max_segment, so we need at least one entry 608 * per zfs_remove_max_segment of allocated data. 609 */ 610 seg_count += to_alloc / zfs_remove_max_segment; 611 612 fnvlist_add_uint64(nv, ZPOOL_CONFIG_INDIRECT_SIZE, 613 seg_count * 614 sizeof (vdev_indirect_mapping_entry_phys_t)); 615 } 616 } 617 618 if (!vd->vdev_ops->vdev_op_leaf) { 619 nvlist_t **child; 620 int c, idx; 621 622 ASSERT(!vd->vdev_ishole); 623 624 child = kmem_alloc(vd->vdev_children * sizeof (nvlist_t *), 625 KM_SLEEP); 626 627 for (c = 0, idx = 0; c < vd->vdev_children; c++) { 628 vdev_t *cvd = vd->vdev_child[c]; 629 630 /* 631 * If we're generating an nvlist of removing 632 * vdevs then skip over any device which is 633 * not being removed. 634 */ 635 if ((flags & VDEV_CONFIG_REMOVING) && 636 !cvd->vdev_removing) 637 continue; 638 639 child[idx++] = vdev_config_generate(spa, cvd, 640 getstats, flags); 641 } 642 643 if (idx) { 644 fnvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, 645 child, idx); 646 } 647 648 for (c = 0; c < idx; c++) 649 nvlist_free(child[c]); 650 651 kmem_free(child, vd->vdev_children * sizeof (nvlist_t *)); 652 653 } else { 654 const char *aux = NULL; 655 656 if (vd->vdev_offline && !vd->vdev_tmpoffline) 657 fnvlist_add_uint64(nv, ZPOOL_CONFIG_OFFLINE, B_TRUE); 658 if (vd->vdev_resilver_txg != 0) 659 fnvlist_add_uint64(nv, ZPOOL_CONFIG_RESILVER_TXG, 660 vd->vdev_resilver_txg); 661 if (vd->vdev_faulted) 662 fnvlist_add_uint64(nv, ZPOOL_CONFIG_FAULTED, B_TRUE); 663 if (vd->vdev_degraded) 664 fnvlist_add_uint64(nv, ZPOOL_CONFIG_DEGRADED, B_TRUE); 665 if (vd->vdev_removed) 666 fnvlist_add_uint64(nv, ZPOOL_CONFIG_REMOVED, B_TRUE); 667 if (vd->vdev_unspare) 668 fnvlist_add_uint64(nv, ZPOOL_CONFIG_UNSPARE, B_TRUE); 669 if (vd->vdev_ishole) 670 fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_HOLE, B_TRUE); 671 672 switch (vd->vdev_stat.vs_aux) { 673 case VDEV_AUX_ERR_EXCEEDED: 674 aux = "err_exceeded"; 675 break; 676 677 case VDEV_AUX_EXTERNAL: 678 aux = "external"; 679 break; 680 } 681 682 if (aux != NULL) 683 fnvlist_add_string(nv, ZPOOL_CONFIG_AUX_STATE, aux); 684 685 if (vd->vdev_splitting && vd->vdev_orig_guid != 0LL) { 686 fnvlist_add_uint64(nv, ZPOOL_CONFIG_ORIG_GUID, 687 vd->vdev_orig_guid); 688 } 689 } 690 691 return (nv); 692 } 693 694 /* 695 * Generate a view of the top-level vdevs. If we currently have holes 696 * in the namespace, then generate an array which contains a list of holey 697 * vdevs. Additionally, add the number of top-level children that currently 698 * exist. 699 */ 700 void 701 vdev_top_config_generate(spa_t *spa, nvlist_t *config) 702 { 703 vdev_t *rvd = spa->spa_root_vdev; 704 uint64_t *array; 705 uint_t c, idx; 706 707 array = kmem_alloc(rvd->vdev_children * sizeof (uint64_t), KM_SLEEP); 708 709 for (c = 0, idx = 0; c < rvd->vdev_children; c++) { 710 vdev_t *tvd = rvd->vdev_child[c]; 711 712 if (tvd->vdev_ishole) { 713 array[idx++] = c; 714 } 715 } 716 717 if (idx) { 718 VERIFY(nvlist_add_uint64_array(config, ZPOOL_CONFIG_HOLE_ARRAY, 719 array, idx) == 0); 720 } 721 722 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN, 723 rvd->vdev_children) == 0); 724 725 kmem_free(array, rvd->vdev_children * sizeof (uint64_t)); 726 } 727 728 /* 729 * Returns the configuration from the label of the given vdev. For vdevs 730 * which don't have a txg value stored on their label (i.e. spares/cache) 731 * or have not been completely initialized (txg = 0) just return 732 * the configuration from the first valid label we find. Otherwise, 733 * find the most up-to-date label that does not exceed the specified 734 * 'txg' value. 735 */ 736 nvlist_t * 737 vdev_label_read_config(vdev_t *vd, uint64_t txg) 738 { 739 spa_t *spa = vd->vdev_spa; 740 nvlist_t *config = NULL; 741 vdev_phys_t *vp; 742 abd_t *vp_abd; 743 zio_t *zio; 744 uint64_t best_txg = 0; 745 uint64_t label_txg = 0; 746 int error = 0; 747 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL | 748 ZIO_FLAG_SPECULATIVE; 749 750 ASSERT(spa_config_held(spa, SCL_STATE_ALL, RW_WRITER) == SCL_STATE_ALL); 751 752 if (!vdev_readable(vd)) 753 return (NULL); 754 755 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE); 756 vp = abd_to_buf(vp_abd); 757 758 retry: 759 for (int l = 0; l < VDEV_LABELS; l++) { 760 nvlist_t *label = NULL; 761 762 zio = zio_root(spa, NULL, NULL, flags); 763 764 vdev_label_read(zio, vd, l, vp_abd, 765 offsetof(vdev_label_t, vl_vdev_phys), 766 sizeof (vdev_phys_t), NULL, NULL, flags); 767 768 if (zio_wait(zio) == 0 && 769 nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist), 770 &label, 0) == 0) { 771 /* 772 * Auxiliary vdevs won't have txg values in their 773 * labels and newly added vdevs may not have been 774 * completely initialized so just return the 775 * configuration from the first valid label we 776 * encounter. 777 */ 778 error = nvlist_lookup_uint64(label, 779 ZPOOL_CONFIG_POOL_TXG, &label_txg); 780 if ((error || label_txg == 0) && !config) { 781 config = label; 782 break; 783 } else if (label_txg <= txg && label_txg > best_txg) { 784 best_txg = label_txg; 785 nvlist_free(config); 786 config = fnvlist_dup(label); 787 } 788 } 789 790 if (label != NULL) { 791 nvlist_free(label); 792 label = NULL; 793 } 794 } 795 796 if (config == NULL && !(flags & ZIO_FLAG_TRYHARD)) { 797 flags |= ZIO_FLAG_TRYHARD; 798 goto retry; 799 } 800 801 /* 802 * We found a valid label but it didn't pass txg restrictions. 803 */ 804 if (config == NULL && label_txg != 0) { 805 vdev_dbgmsg(vd, "label discarded as txg is too large " 806 "(%llu > %llu)", (u_longlong_t)label_txg, 807 (u_longlong_t)txg); 808 } 809 810 abd_free(vp_abd); 811 812 return (config); 813 } 814 815 /* 816 * Determine if a device is in use. The 'spare_guid' parameter will be filled 817 * in with the device guid if this spare is active elsewhere on the system. 818 */ 819 static boolean_t 820 vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason, 821 uint64_t *spare_guid, uint64_t *l2cache_guid) 822 { 823 spa_t *spa = vd->vdev_spa; 824 uint64_t state, pool_guid, device_guid, txg, spare_pool; 825 uint64_t vdtxg = 0; 826 nvlist_t *label; 827 828 if (spare_guid) 829 *spare_guid = 0ULL; 830 if (l2cache_guid) 831 *l2cache_guid = 0ULL; 832 833 /* 834 * Read the label, if any, and perform some basic sanity checks. 835 */ 836 if ((label = vdev_label_read_config(vd, -1ULL)) == NULL) 837 return (B_FALSE); 838 839 (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG, 840 &vdtxg); 841 842 if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, 843 &state) != 0 || 844 nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, 845 &device_guid) != 0) { 846 nvlist_free(label); 847 return (B_FALSE); 848 } 849 850 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && 851 (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID, 852 &pool_guid) != 0 || 853 nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG, 854 &txg) != 0)) { 855 nvlist_free(label); 856 return (B_FALSE); 857 } 858 859 nvlist_free(label); 860 861 /* 862 * Check to see if this device indeed belongs to the pool it claims to 863 * be a part of. The only way this is allowed is if the device is a hot 864 * spare (which we check for later on). 865 */ 866 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && 867 !spa_guid_exists(pool_guid, device_guid) && 868 !spa_spare_exists(device_guid, NULL, NULL) && 869 !spa_l2cache_exists(device_guid, NULL)) 870 return (B_FALSE); 871 872 /* 873 * If the transaction group is zero, then this an initialized (but 874 * unused) label. This is only an error if the create transaction 875 * on-disk is the same as the one we're using now, in which case the 876 * user has attempted to add the same vdev multiple times in the same 877 * transaction. 878 */ 879 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && 880 txg == 0 && vdtxg == crtxg) 881 return (B_TRUE); 882 883 /* 884 * Check to see if this is a spare device. We do an explicit check for 885 * spa_has_spare() here because it may be on our pending list of spares 886 * to add. We also check if it is an l2cache device. 887 */ 888 if (spa_spare_exists(device_guid, &spare_pool, NULL) || 889 spa_has_spare(spa, device_guid)) { 890 if (spare_guid) 891 *spare_guid = device_guid; 892 893 switch (reason) { 894 case VDEV_LABEL_CREATE: 895 case VDEV_LABEL_L2CACHE: 896 return (B_TRUE); 897 898 case VDEV_LABEL_REPLACE: 899 return (!spa_has_spare(spa, device_guid) || 900 spare_pool != 0ULL); 901 902 case VDEV_LABEL_SPARE: 903 return (spa_has_spare(spa, device_guid)); 904 } 905 } 906 907 /* 908 * Check to see if this is an l2cache device. 909 */ 910 if (spa_l2cache_exists(device_guid, NULL)) 911 return (B_TRUE); 912 913 /* 914 * We can't rely on a pool's state if it's been imported 915 * read-only. Instead we look to see if the pools is marked 916 * read-only in the namespace and set the state to active. 917 */ 918 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE && 919 (spa = spa_by_guid(pool_guid, device_guid)) != NULL && 920 spa_mode(spa) == FREAD) 921 state = POOL_STATE_ACTIVE; 922 923 /* 924 * If the device is marked ACTIVE, then this device is in use by another 925 * pool on the system. 926 */ 927 return (state == POOL_STATE_ACTIVE); 928 } 929 930 /* 931 * Initialize a vdev label. We check to make sure each leaf device is not in 932 * use, and writable. We put down an initial label which we will later 933 * overwrite with a complete label. Note that it's important to do this 934 * sequentially, not in parallel, so that we catch cases of multiple use of the 935 * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with 936 * itself. 937 */ 938 int 939 vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason) 940 { 941 spa_t *spa = vd->vdev_spa; 942 nvlist_t *label; 943 vdev_phys_t *vp; 944 abd_t *vp_abd; 945 abd_t *bootenv; 946 uberblock_t *ub; 947 abd_t *ub_abd; 948 zio_t *zio; 949 char *buf; 950 size_t buflen; 951 int error; 952 uint64_t spare_guid, l2cache_guid; 953 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL; 954 955 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); 956 957 for (int c = 0; c < vd->vdev_children; c++) 958 if ((error = vdev_label_init(vd->vdev_child[c], 959 crtxg, reason)) != 0) 960 return (error); 961 962 /* Track the creation time for this vdev */ 963 vd->vdev_crtxg = crtxg; 964 965 if (!vd->vdev_ops->vdev_op_leaf || !spa_writeable(spa)) 966 return (0); 967 968 /* 969 * Dead vdevs cannot be initialized. 970 */ 971 if (vdev_is_dead(vd)) 972 return (SET_ERROR(EIO)); 973 974 /* 975 * Determine if the vdev is in use. 976 */ 977 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_SPLIT && 978 vdev_inuse(vd, crtxg, reason, &spare_guid, &l2cache_guid)) 979 return (SET_ERROR(EBUSY)); 980 981 /* 982 * If this is a request to add or replace a spare or l2cache device 983 * that is in use elsewhere on the system, then we must update the 984 * guid (which was initialized to a random value) to reflect the 985 * actual GUID (which is shared between multiple pools). 986 */ 987 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_L2CACHE && 988 spare_guid != 0ULL) { 989 uint64_t guid_delta = spare_guid - vd->vdev_guid; 990 991 vd->vdev_guid += guid_delta; 992 993 for (vdev_t *pvd = vd; pvd != NULL; pvd = pvd->vdev_parent) 994 pvd->vdev_guid_sum += guid_delta; 995 996 /* 997 * If this is a replacement, then we want to fallthrough to the 998 * rest of the code. If we're adding a spare, then it's already 999 * labeled appropriately and we can just return. 1000 */ 1001 if (reason == VDEV_LABEL_SPARE) 1002 return (0); 1003 ASSERT(reason == VDEV_LABEL_REPLACE || 1004 reason == VDEV_LABEL_SPLIT); 1005 } 1006 1007 if (reason != VDEV_LABEL_REMOVE && reason != VDEV_LABEL_SPARE && 1008 l2cache_guid != 0ULL) { 1009 uint64_t guid_delta = l2cache_guid - vd->vdev_guid; 1010 1011 vd->vdev_guid += guid_delta; 1012 1013 for (vdev_t *pvd = vd; pvd != NULL; pvd = pvd->vdev_parent) 1014 pvd->vdev_guid_sum += guid_delta; 1015 1016 /* 1017 * If this is a replacement, then we want to fallthrough to the 1018 * rest of the code. If we're adding an l2cache, then it's 1019 * already labeled appropriately and we can just return. 1020 */ 1021 if (reason == VDEV_LABEL_L2CACHE) 1022 return (0); 1023 ASSERT(reason == VDEV_LABEL_REPLACE); 1024 } 1025 1026 /* 1027 * Initialize its label. 1028 */ 1029 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE); 1030 abd_zero(vp_abd, sizeof (vdev_phys_t)); 1031 vp = abd_to_buf(vp_abd); 1032 1033 /* 1034 * Generate a label describing the pool and our top-level vdev. 1035 * We mark it as being from txg 0 to indicate that it's not 1036 * really part of an active pool just yet. The labels will 1037 * be written again with a meaningful txg by spa_sync(). 1038 */ 1039 if (reason == VDEV_LABEL_SPARE || 1040 (reason == VDEV_LABEL_REMOVE && vd->vdev_isspare)) { 1041 /* 1042 * For inactive hot spares, we generate a special label that 1043 * identifies as a mutually shared hot spare. We write the 1044 * label if we are adding a hot spare, or if we are removing an 1045 * active hot spare (in which case we want to revert the 1046 * labels). 1047 */ 1048 VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1049 1050 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, 1051 spa_version(spa)) == 0); 1052 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, 1053 POOL_STATE_SPARE) == 0); 1054 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, 1055 vd->vdev_guid) == 0); 1056 } else if (reason == VDEV_LABEL_L2CACHE || 1057 (reason == VDEV_LABEL_REMOVE && vd->vdev_isl2cache)) { 1058 /* 1059 * For level 2 ARC devices, add a special label. 1060 */ 1061 VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1062 1063 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, 1064 spa_version(spa)) == 0); 1065 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, 1066 POOL_STATE_L2CACHE) == 0); 1067 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, 1068 vd->vdev_guid) == 0); 1069 } else { 1070 uint64_t txg = 0ULL; 1071 1072 if (reason == VDEV_LABEL_SPLIT) 1073 txg = spa->spa_uberblock.ub_txg; 1074 label = spa_config_generate(spa, vd, txg, B_FALSE); 1075 1076 /* 1077 * Add our creation time. This allows us to detect multiple 1078 * vdev uses as described above, and automatically expires if we 1079 * fail. 1080 */ 1081 VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_CREATE_TXG, 1082 crtxg) == 0); 1083 } 1084 1085 buf = vp->vp_nvlist; 1086 buflen = sizeof (vp->vp_nvlist); 1087 1088 error = nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP); 1089 if (error != 0) { 1090 nvlist_free(label); 1091 abd_free(vp_abd); 1092 /* EFAULT means nvlist_pack ran out of room */ 1093 return (error == EFAULT ? ENAMETOOLONG : EINVAL); 1094 } 1095 1096 /* 1097 * Initialize uberblock template. 1098 */ 1099 ub_abd = abd_alloc_linear(VDEV_UBERBLOCK_RING, B_TRUE); 1100 abd_zero(ub_abd, VDEV_UBERBLOCK_RING); 1101 abd_copy_from_buf(ub_abd, &spa->spa_uberblock, sizeof (uberblock_t)); 1102 ub = abd_to_buf(ub_abd); 1103 ub->ub_txg = 0; 1104 1105 /* Initialize the 2nd padding area. */ 1106 bootenv = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE); 1107 abd_zero(bootenv, VDEV_PAD_SIZE); 1108 1109 /* 1110 * Write everything in parallel. 1111 */ 1112 retry: 1113 zio = zio_root(spa, NULL, NULL, flags); 1114 1115 for (int l = 0; l < VDEV_LABELS; l++) { 1116 1117 vdev_label_write(zio, vd, l, vp_abd, 1118 offsetof(vdev_label_t, vl_vdev_phys), 1119 sizeof (vdev_phys_t), NULL, NULL, flags); 1120 1121 /* 1122 * Skip the 1st padding area. 1123 * Zero out the 2nd padding area where it might have 1124 * left over data from previous filesystem format. 1125 */ 1126 vdev_label_write(zio, vd, l, bootenv, 1127 offsetof(vdev_label_t, vl_be), 1128 VDEV_PAD_SIZE, NULL, NULL, flags); 1129 1130 vdev_label_write(zio, vd, l, ub_abd, 1131 offsetof(vdev_label_t, vl_uberblock), 1132 VDEV_UBERBLOCK_RING, NULL, NULL, flags); 1133 } 1134 1135 error = zio_wait(zio); 1136 1137 if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) { 1138 flags |= ZIO_FLAG_TRYHARD; 1139 goto retry; 1140 } 1141 1142 nvlist_free(label); 1143 abd_free(bootenv); 1144 abd_free(ub_abd); 1145 abd_free(vp_abd); 1146 1147 /* 1148 * If this vdev hasn't been previously identified as a spare, then we 1149 * mark it as such only if a) we are labeling it as a spare, or b) it 1150 * exists as a spare elsewhere in the system. Do the same for 1151 * level 2 ARC devices. 1152 */ 1153 if (error == 0 && !vd->vdev_isspare && 1154 (reason == VDEV_LABEL_SPARE || 1155 spa_spare_exists(vd->vdev_guid, NULL, NULL))) 1156 spa_spare_add(vd); 1157 1158 if (error == 0 && !vd->vdev_isl2cache && 1159 (reason == VDEV_LABEL_L2CACHE || 1160 spa_l2cache_exists(vd->vdev_guid, NULL))) 1161 spa_l2cache_add(vd); 1162 1163 return (error); 1164 } 1165 1166 /* 1167 * Done callback for vdev_label_read_bootenv_impl. If this is the first 1168 * callback to finish, store our abd in the callback pointer. Otherwise, we 1169 * just free our abd and return. 1170 */ 1171 static void 1172 vdev_label_read_bootenv_done(zio_t *zio) 1173 { 1174 zio_t *rio = zio->io_private; 1175 abd_t **cbp = rio->io_private; 1176 1177 ASSERT3U(zio->io_size, ==, VDEV_PAD_SIZE); 1178 1179 if (zio->io_error == 0) { 1180 mutex_enter(&rio->io_lock); 1181 if (*cbp == NULL) { 1182 /* Will free this buffer in vdev_label_read_bootenv. */ 1183 *cbp = zio->io_abd; 1184 } else { 1185 abd_free(zio->io_abd); 1186 } 1187 mutex_exit(&rio->io_lock); 1188 } else { 1189 abd_free(zio->io_abd); 1190 } 1191 } 1192 1193 static void 1194 vdev_label_read_bootenv_impl(zio_t *zio, vdev_t *vd, int flags) 1195 { 1196 for (int c = 0; c < vd->vdev_children; c++) 1197 vdev_label_read_bootenv_impl(zio, vd->vdev_child[c], flags); 1198 1199 /* 1200 * We just use the first label that has a correct checksum; the 1201 * bootloader should have rewritten them all to be the same on boot, 1202 * and any changes we made since boot have been the same across all 1203 * labels. 1204 */ 1205 if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) { 1206 for (int l = 0; l < VDEV_LABELS; l++) { 1207 vdev_label_read(zio, vd, l, 1208 abd_alloc_linear(VDEV_PAD_SIZE, B_FALSE), 1209 offsetof(vdev_label_t, vl_be), VDEV_PAD_SIZE, 1210 vdev_label_read_bootenv_done, zio, flags); 1211 } 1212 } 1213 } 1214 1215 int 1216 vdev_label_read_bootenv(vdev_t *rvd, nvlist_t *bootenv) 1217 { 1218 nvlist_t *config; 1219 spa_t *spa = rvd->vdev_spa; 1220 abd_t *abd = NULL; 1221 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL | 1222 ZIO_FLAG_SPECULATIVE | ZIO_FLAG_TRYHARD; 1223 1224 ASSERT(bootenv); 1225 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); 1226 1227 zio_t *zio = zio_root(spa, NULL, &abd, flags); 1228 vdev_label_read_bootenv_impl(zio, rvd, flags); 1229 int err = zio_wait(zio); 1230 1231 if (abd != NULL) { 1232 char *buf; 1233 vdev_boot_envblock_t *vbe = abd_to_buf(abd); 1234 1235 vbe->vbe_version = ntohll(vbe->vbe_version); 1236 switch (vbe->vbe_version) { 1237 case VB_RAW: 1238 /* 1239 * if we have textual data in vbe_bootenv, create nvlist 1240 * with key "envmap". 1241 */ 1242 fnvlist_add_uint64(bootenv, BOOTENV_VERSION, VB_RAW); 1243 vbe->vbe_bootenv[sizeof (vbe->vbe_bootenv) - 1] = '\0'; 1244 fnvlist_add_string(bootenv, GRUB_ENVMAP, 1245 vbe->vbe_bootenv); 1246 break; 1247 1248 case VB_NVLIST: 1249 err = nvlist_unpack(vbe->vbe_bootenv, 1250 sizeof (vbe->vbe_bootenv), &config, 0); 1251 if (err == 0) { 1252 fnvlist_merge(bootenv, config); 1253 nvlist_free(config); 1254 break; 1255 } 1256 /* FALLTHROUGH */ 1257 default: 1258 /* Check for FreeBSD zfs bootonce command string */ 1259 buf = abd_to_buf(abd); 1260 if (*buf == '\0') { 1261 fnvlist_add_uint64(bootenv, BOOTENV_VERSION, 1262 VB_NVLIST); 1263 break; 1264 } 1265 fnvlist_add_string(bootenv, FREEBSD_BOOTONCE, buf); 1266 } 1267 1268 /* 1269 * abd was allocated in vdev_label_read_bootenv_impl() 1270 */ 1271 abd_free(abd); 1272 /* 1273 * If we managed to read any successfully, 1274 * return success. 1275 */ 1276 return (0); 1277 } 1278 return (err); 1279 } 1280 1281 int 1282 vdev_label_write_bootenv(vdev_t *vd, nvlist_t *env) 1283 { 1284 zio_t *zio; 1285 spa_t *spa = vd->vdev_spa; 1286 vdev_boot_envblock_t *bootenv; 1287 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL; 1288 int error; 1289 size_t nvsize; 1290 char *nvbuf; 1291 1292 error = nvlist_size(env, &nvsize, NV_ENCODE_XDR); 1293 if (error != 0) 1294 return (SET_ERROR(error)); 1295 1296 if (nvsize >= sizeof (bootenv->vbe_bootenv)) { 1297 return (SET_ERROR(E2BIG)); 1298 } 1299 1300 ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL); 1301 1302 error = ENXIO; 1303 for (int c = 0; c < vd->vdev_children; c++) { 1304 int child_err; 1305 1306 child_err = vdev_label_write_bootenv(vd->vdev_child[c], env); 1307 /* 1308 * As long as any of the disks managed to write all of their 1309 * labels successfully, return success. 1310 */ 1311 if (child_err == 0) 1312 error = child_err; 1313 } 1314 1315 if (!vd->vdev_ops->vdev_op_leaf || vdev_is_dead(vd) || 1316 !vdev_writeable(vd)) { 1317 return (error); 1318 } 1319 ASSERT3U(sizeof (*bootenv), ==, VDEV_PAD_SIZE); 1320 abd_t *abd = abd_alloc_for_io(VDEV_PAD_SIZE, B_TRUE); 1321 abd_zero(abd, VDEV_PAD_SIZE); 1322 1323 bootenv = abd_borrow_buf_copy(abd, VDEV_PAD_SIZE); 1324 nvbuf = bootenv->vbe_bootenv; 1325 nvsize = sizeof (bootenv->vbe_bootenv); 1326 1327 bootenv->vbe_version = fnvlist_lookup_uint64(env, BOOTENV_VERSION); 1328 switch (bootenv->vbe_version) { 1329 case VB_RAW: 1330 if (nvlist_lookup_string(env, GRUB_ENVMAP, &nvbuf) == 0) { 1331 (void) strlcpy(bootenv->vbe_bootenv, nvbuf, nvsize); 1332 } 1333 error = 0; 1334 break; 1335 1336 case VB_NVLIST: 1337 error = nvlist_pack(env, &nvbuf, &nvsize, NV_ENCODE_XDR, 1338 KM_SLEEP); 1339 break; 1340 1341 default: 1342 error = EINVAL; 1343 break; 1344 } 1345 1346 if (error == 0) { 1347 bootenv->vbe_version = htonll(bootenv->vbe_version); 1348 abd_return_buf_copy(abd, bootenv, VDEV_PAD_SIZE); 1349 } else { 1350 abd_free(abd); 1351 return (SET_ERROR(error)); 1352 } 1353 1354 retry: 1355 zio = zio_root(spa, NULL, NULL, flags); 1356 for (int l = 0; l < VDEV_LABELS; l++) { 1357 vdev_label_write(zio, vd, l, abd, 1358 offsetof(vdev_label_t, vl_be), 1359 VDEV_PAD_SIZE, NULL, NULL, flags); 1360 } 1361 1362 error = zio_wait(zio); 1363 if (error != 0 && !(flags & ZIO_FLAG_TRYHARD)) { 1364 flags |= ZIO_FLAG_TRYHARD; 1365 goto retry; 1366 } 1367 1368 abd_free(abd); 1369 return (error); 1370 } 1371 1372 /* 1373 * ========================================================================== 1374 * uberblock load/sync 1375 * ========================================================================== 1376 */ 1377 1378 /* 1379 * Consider the following situation: txg is safely synced to disk. We've 1380 * written the first uberblock for txg + 1, and then we lose power. When we 1381 * come back up, we fail to see the uberblock for txg + 1 because, say, 1382 * it was on a mirrored device and the replica to which we wrote txg + 1 1383 * is now offline. If we then make some changes and sync txg + 1, and then 1384 * the missing replica comes back, then for a few seconds we'll have two 1385 * conflicting uberblocks on disk with the same txg. The solution is simple: 1386 * among uberblocks with equal txg, choose the one with the latest timestamp. 1387 */ 1388 static int 1389 vdev_uberblock_compare(const uberblock_t *ub1, const uberblock_t *ub2) 1390 { 1391 int cmp = TREE_CMP(ub1->ub_txg, ub2->ub_txg); 1392 1393 if (likely(cmp)) 1394 return (cmp); 1395 1396 cmp = TREE_CMP(ub1->ub_timestamp, ub2->ub_timestamp); 1397 if (likely(cmp)) 1398 return (cmp); 1399 1400 /* 1401 * If MMP_VALID(ub) && MMP_SEQ_VALID(ub) then the host has an MMP-aware 1402 * ZFS, e.g. zfsonlinux >= 0.7. 1403 * 1404 * If one ub has MMP and the other does not, they were written by 1405 * different hosts, which matters for MMP. So we treat no MMP/no SEQ as 1406 * a 0 value. 1407 * 1408 * Since timestamp and txg are the same if we get this far, either is 1409 * acceptable for importing the pool. 1410 */ 1411 unsigned int seq1 = 0; 1412 unsigned int seq2 = 0; 1413 1414 if (MMP_VALID(ub1) && MMP_SEQ_VALID(ub1)) 1415 seq1 = MMP_SEQ(ub1); 1416 1417 if (MMP_VALID(ub2) && MMP_SEQ_VALID(ub2)) 1418 seq2 = MMP_SEQ(ub2); 1419 1420 return (TREE_CMP(seq1, seq2)); 1421 } 1422 1423 struct ubl_cbdata { 1424 uberblock_t *ubl_ubbest; /* Best uberblock */ 1425 vdev_t *ubl_vd; /* vdev associated with the above */ 1426 }; 1427 1428 static void 1429 vdev_uberblock_load_done(zio_t *zio) 1430 { 1431 vdev_t *vd = zio->io_vd; 1432 spa_t *spa = zio->io_spa; 1433 zio_t *rio = zio->io_private; 1434 uberblock_t *ub = abd_to_buf(zio->io_abd); 1435 struct ubl_cbdata *cbp = rio->io_private; 1436 1437 ASSERT3U(zio->io_size, ==, VDEV_UBERBLOCK_SIZE(vd)); 1438 1439 if (zio->io_error == 0 && uberblock_verify(ub) == 0) { 1440 mutex_enter(&rio->io_lock); 1441 if (ub->ub_txg <= spa->spa_load_max_txg && 1442 vdev_uberblock_compare(ub, cbp->ubl_ubbest) > 0) { 1443 /* 1444 * Keep track of the vdev in which this uberblock 1445 * was found. We will use this information later 1446 * to obtain the config nvlist associated with 1447 * this uberblock. 1448 */ 1449 *cbp->ubl_ubbest = *ub; 1450 cbp->ubl_vd = vd; 1451 } 1452 mutex_exit(&rio->io_lock); 1453 } 1454 1455 abd_free(zio->io_abd); 1456 } 1457 1458 static void 1459 vdev_uberblock_load_impl(zio_t *zio, vdev_t *vd, int flags, 1460 struct ubl_cbdata *cbp) 1461 { 1462 for (int c = 0; c < vd->vdev_children; c++) 1463 vdev_uberblock_load_impl(zio, vd->vdev_child[c], flags, cbp); 1464 1465 if (vd->vdev_ops->vdev_op_leaf && vdev_readable(vd)) { 1466 for (int l = 0; l < VDEV_LABELS; l++) { 1467 for (int n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { 1468 vdev_label_read(zio, vd, l, 1469 abd_alloc_linear(VDEV_UBERBLOCK_SIZE(vd), 1470 B_TRUE), VDEV_UBERBLOCK_OFFSET(vd, n), 1471 VDEV_UBERBLOCK_SIZE(vd), 1472 vdev_uberblock_load_done, zio, flags); 1473 } 1474 } 1475 } 1476 } 1477 1478 /* 1479 * Reads the 'best' uberblock from disk along with its associated 1480 * configuration. First, we read the uberblock array of each label of each 1481 * vdev, keeping track of the uberblock with the highest txg in each array. 1482 * Then, we read the configuration from the same vdev as the best uberblock. 1483 */ 1484 void 1485 vdev_uberblock_load(vdev_t *rvd, uberblock_t *ub, nvlist_t **config) 1486 { 1487 zio_t *zio; 1488 spa_t *spa = rvd->vdev_spa; 1489 struct ubl_cbdata cb; 1490 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL | 1491 ZIO_FLAG_SPECULATIVE | ZIO_FLAG_TRYHARD; 1492 1493 ASSERT(ub); 1494 ASSERT(config); 1495 1496 bzero(ub, sizeof (uberblock_t)); 1497 *config = NULL; 1498 1499 cb.ubl_ubbest = ub; 1500 cb.ubl_vd = NULL; 1501 1502 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1503 zio = zio_root(spa, NULL, &cb, flags); 1504 vdev_uberblock_load_impl(zio, rvd, flags, &cb); 1505 (void) zio_wait(zio); 1506 1507 /* 1508 * It's possible that the best uberblock was discovered on a label 1509 * that has a configuration which was written in a future txg. 1510 * Search all labels on this vdev to find the configuration that 1511 * matches the txg for our uberblock. 1512 */ 1513 if (cb.ubl_vd != NULL) { 1514 vdev_dbgmsg(cb.ubl_vd, "best uberblock found for spa %s. " 1515 "txg %llu", spa->spa_name, (u_longlong_t)ub->ub_txg); 1516 1517 *config = vdev_label_read_config(cb.ubl_vd, ub->ub_txg); 1518 if (*config == NULL && spa->spa_extreme_rewind) { 1519 vdev_dbgmsg(cb.ubl_vd, "failed to read label config. " 1520 "Trying again without txg restrictions."); 1521 *config = vdev_label_read_config(cb.ubl_vd, UINT64_MAX); 1522 } 1523 if (*config == NULL) { 1524 vdev_dbgmsg(cb.ubl_vd, "failed to read label config"); 1525 } 1526 } 1527 spa_config_exit(spa, SCL_ALL, FTAG); 1528 } 1529 1530 /* 1531 * On success, increment root zio's count of good writes. 1532 * We only get credit for writes to known-visible vdevs; see spa_vdev_add(). 1533 */ 1534 static void 1535 vdev_uberblock_sync_done(zio_t *zio) 1536 { 1537 uint64_t *good_writes = zio->io_private; 1538 1539 if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0) 1540 atomic_inc_64(good_writes); 1541 } 1542 1543 /* 1544 * Write the uberblock to all labels of all leaves of the specified vdev. 1545 */ 1546 static void 1547 vdev_uberblock_sync(zio_t *zio, uint64_t *good_writes, 1548 uberblock_t *ub, vdev_t *vd, int flags) 1549 { 1550 for (uint64_t c = 0; c < vd->vdev_children; c++) { 1551 vdev_uberblock_sync(zio, good_writes, 1552 ub, vd->vdev_child[c], flags); 1553 } 1554 1555 if (!vd->vdev_ops->vdev_op_leaf) 1556 return; 1557 1558 if (!vdev_writeable(vd)) 1559 return; 1560 1561 int m = spa_multihost(vd->vdev_spa) ? MMP_BLOCKS_PER_LABEL : 0; 1562 int n = ub->ub_txg % (VDEV_UBERBLOCK_COUNT(vd) - m); 1563 1564 /* Copy the uberblock_t into the ABD */ 1565 abd_t *ub_abd = abd_alloc_for_io(VDEV_UBERBLOCK_SIZE(vd), B_TRUE); 1566 abd_zero(ub_abd, VDEV_UBERBLOCK_SIZE(vd)); 1567 abd_copy_from_buf(ub_abd, ub, sizeof (uberblock_t)); 1568 1569 for (int l = 0; l < VDEV_LABELS; l++) 1570 vdev_label_write(zio, vd, l, ub_abd, 1571 VDEV_UBERBLOCK_OFFSET(vd, n), VDEV_UBERBLOCK_SIZE(vd), 1572 vdev_uberblock_sync_done, good_writes, 1573 flags | ZIO_FLAG_DONT_PROPAGATE); 1574 1575 abd_free(ub_abd); 1576 } 1577 1578 /* Sync the uberblocks to all vdevs in svd[] */ 1579 int 1580 vdev_uberblock_sync_list(vdev_t **svd, int svdcount, uberblock_t *ub, int flags) 1581 { 1582 spa_t *spa = svd[0]->vdev_spa; 1583 zio_t *zio; 1584 uint64_t good_writes = 0; 1585 1586 zio = zio_root(spa, NULL, NULL, flags); 1587 1588 for (int v = 0; v < svdcount; v++) 1589 vdev_uberblock_sync(zio, &good_writes, ub, svd[v], flags); 1590 1591 (void) zio_wait(zio); 1592 1593 /* 1594 * Flush the uberblocks to disk. This ensures that the odd labels 1595 * are no longer needed (because the new uberblocks and the even 1596 * labels are safely on disk), so it is safe to overwrite them. 1597 */ 1598 zio = zio_root(spa, NULL, NULL, flags); 1599 1600 for (int v = 0; v < svdcount; v++) { 1601 if (vdev_writeable(svd[v])) { 1602 zio_flush(zio, svd[v]); 1603 } 1604 } 1605 1606 (void) zio_wait(zio); 1607 1608 return (good_writes >= 1 ? 0 : EIO); 1609 } 1610 1611 /* 1612 * On success, increment the count of good writes for our top-level vdev. 1613 */ 1614 static void 1615 vdev_label_sync_done(zio_t *zio) 1616 { 1617 uint64_t *good_writes = zio->io_private; 1618 1619 if (zio->io_error == 0) 1620 atomic_inc_64(good_writes); 1621 } 1622 1623 /* 1624 * If there weren't enough good writes, indicate failure to the parent. 1625 */ 1626 static void 1627 vdev_label_sync_top_done(zio_t *zio) 1628 { 1629 uint64_t *good_writes = zio->io_private; 1630 1631 if (*good_writes == 0) 1632 zio->io_error = SET_ERROR(EIO); 1633 1634 kmem_free(good_writes, sizeof (uint64_t)); 1635 } 1636 1637 /* 1638 * We ignore errors for log and cache devices, simply free the private data. 1639 */ 1640 static void 1641 vdev_label_sync_ignore_done(zio_t *zio) 1642 { 1643 kmem_free(zio->io_private, sizeof (uint64_t)); 1644 } 1645 1646 /* 1647 * Write all even or odd labels to all leaves of the specified vdev. 1648 */ 1649 static void 1650 vdev_label_sync(zio_t *zio, uint64_t *good_writes, 1651 vdev_t *vd, int l, uint64_t txg, int flags) 1652 { 1653 nvlist_t *label; 1654 vdev_phys_t *vp; 1655 abd_t *vp_abd; 1656 char *buf; 1657 size_t buflen; 1658 1659 for (int c = 0; c < vd->vdev_children; c++) { 1660 vdev_label_sync(zio, good_writes, 1661 vd->vdev_child[c], l, txg, flags); 1662 } 1663 1664 if (!vd->vdev_ops->vdev_op_leaf) 1665 return; 1666 1667 if (!vdev_writeable(vd)) 1668 return; 1669 1670 /* 1671 * Generate a label describing the top-level config to which we belong. 1672 */ 1673 label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE); 1674 1675 vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE); 1676 abd_zero(vp_abd, sizeof (vdev_phys_t)); 1677 vp = abd_to_buf(vp_abd); 1678 1679 buf = vp->vp_nvlist; 1680 buflen = sizeof (vp->vp_nvlist); 1681 1682 if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) == 0) { 1683 for (; l < VDEV_LABELS; l += 2) { 1684 vdev_label_write(zio, vd, l, vp_abd, 1685 offsetof(vdev_label_t, vl_vdev_phys), 1686 sizeof (vdev_phys_t), 1687 vdev_label_sync_done, good_writes, 1688 flags | ZIO_FLAG_DONT_PROPAGATE); 1689 } 1690 } 1691 1692 abd_free(vp_abd); 1693 nvlist_free(label); 1694 } 1695 1696 int 1697 vdev_label_sync_list(spa_t *spa, int l, uint64_t txg, int flags) 1698 { 1699 list_t *dl = &spa->spa_config_dirty_list; 1700 vdev_t *vd; 1701 zio_t *zio; 1702 int error; 1703 1704 /* 1705 * Write the new labels to disk. 1706 */ 1707 zio = zio_root(spa, NULL, NULL, flags); 1708 1709 for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd)) { 1710 uint64_t *good_writes = kmem_zalloc(sizeof (uint64_t), 1711 KM_SLEEP); 1712 1713 ASSERT(!vd->vdev_ishole); 1714 1715 zio_t *vio = zio_null(zio, spa, NULL, 1716 (vd->vdev_islog || vd->vdev_aux != NULL) ? 1717 vdev_label_sync_ignore_done : vdev_label_sync_top_done, 1718 good_writes, flags); 1719 vdev_label_sync(vio, good_writes, vd, l, txg, flags); 1720 zio_nowait(vio); 1721 } 1722 1723 error = zio_wait(zio); 1724 1725 /* 1726 * Flush the new labels to disk. 1727 */ 1728 zio = zio_root(spa, NULL, NULL, flags); 1729 1730 for (vd = list_head(dl); vd != NULL; vd = list_next(dl, vd)) 1731 zio_flush(zio, vd); 1732 1733 (void) zio_wait(zio); 1734 1735 return (error); 1736 } 1737 1738 /* 1739 * Sync the uberblock and any changes to the vdev configuration. 1740 * 1741 * The order of operations is carefully crafted to ensure that 1742 * if the system panics or loses power at any time, the state on disk 1743 * is still transactionally consistent. The in-line comments below 1744 * describe the failure semantics at each stage. 1745 * 1746 * Moreover, vdev_config_sync() is designed to be idempotent: if it fails 1747 * at any time, you can just call it again, and it will resume its work. 1748 */ 1749 int 1750 vdev_config_sync(vdev_t **svd, int svdcount, uint64_t txg) 1751 { 1752 spa_t *spa = svd[0]->vdev_spa; 1753 uberblock_t *ub = &spa->spa_uberblock; 1754 int error = 0; 1755 int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL; 1756 1757 ASSERT(svdcount != 0); 1758 retry: 1759 /* 1760 * Normally, we don't want to try too hard to write every label and 1761 * uberblock. If there is a flaky disk, we don't want the rest of the 1762 * sync process to block while we retry. But if we can't write a 1763 * single label out, we should retry with ZIO_FLAG_TRYHARD before 1764 * bailing out and declaring the pool faulted. 1765 */ 1766 if (error != 0) { 1767 if ((flags & ZIO_FLAG_TRYHARD) != 0) 1768 return (error); 1769 flags |= ZIO_FLAG_TRYHARD; 1770 } 1771 1772 ASSERT(ub->ub_txg <= txg); 1773 1774 /* 1775 * If this isn't a resync due to I/O errors, 1776 * and nothing changed in this transaction group, 1777 * and the vdev configuration hasn't changed, 1778 * then there's nothing to do. 1779 */ 1780 if (ub->ub_txg < txg) { 1781 boolean_t changed = uberblock_update(ub, spa->spa_root_vdev, 1782 txg, spa->spa_mmp.mmp_delay); 1783 1784 if (!changed && list_is_empty(&spa->spa_config_dirty_list)) 1785 return (0); 1786 } 1787 1788 if (txg > spa_freeze_txg(spa)) 1789 return (0); 1790 1791 ASSERT(txg <= spa->spa_final_txg); 1792 1793 /* 1794 * Flush the write cache of every disk that's been written to 1795 * in this transaction group. This ensures that all blocks 1796 * written in this txg will be committed to stable storage 1797 * before any uberblock that references them. 1798 */ 1799 zio_t *zio = zio_root(spa, NULL, NULL, flags); 1800 1801 for (vdev_t *vd = 1802 txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd != NULL; 1803 vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg))) 1804 zio_flush(zio, vd); 1805 1806 (void) zio_wait(zio); 1807 1808 /* 1809 * Sync out the even labels (L0, L2) for every dirty vdev. If the 1810 * system dies in the middle of this process, that's OK: all of the 1811 * even labels that made it to disk will be newer than any uberblock, 1812 * and will therefore be considered invalid. The odd labels (L1, L3), 1813 * which have not yet been touched, will still be valid. We flush 1814 * the new labels to disk to ensure that all even-label updates 1815 * are committed to stable storage before the uberblock update. 1816 */ 1817 if ((error = vdev_label_sync_list(spa, 0, txg, flags)) != 0) { 1818 if ((flags & ZIO_FLAG_TRYHARD) != 0) { 1819 zfs_dbgmsg("vdev_label_sync_list() returned error %d " 1820 "for pool '%s' when syncing out the even labels " 1821 "of dirty vdevs", error, spa_name(spa)); 1822 } 1823 goto retry; 1824 } 1825 1826 /* 1827 * Sync the uberblocks to all vdevs in svd[]. 1828 * If the system dies in the middle of this step, there are two cases 1829 * to consider, and the on-disk state is consistent either way: 1830 * 1831 * (1) If none of the new uberblocks made it to disk, then the 1832 * previous uberblock will be the newest, and the odd labels 1833 * (which had not yet been touched) will be valid with respect 1834 * to that uberblock. 1835 * 1836 * (2) If one or more new uberblocks made it to disk, then they 1837 * will be the newest, and the even labels (which had all 1838 * been successfully committed) will be valid with respect 1839 * to the new uberblocks. 1840 */ 1841 if ((error = vdev_uberblock_sync_list(svd, svdcount, ub, flags)) != 0) { 1842 if ((flags & ZIO_FLAG_TRYHARD) != 0) { 1843 zfs_dbgmsg("vdev_uberblock_sync_list() returned error " 1844 "%d for pool '%s'", error, spa_name(spa)); 1845 } 1846 goto retry; 1847 } 1848 1849 if (spa_multihost(spa)) 1850 mmp_update_uberblock(spa, ub); 1851 1852 /* 1853 * Sync out odd labels for every dirty vdev. If the system dies 1854 * in the middle of this process, the even labels and the new 1855 * uberblocks will suffice to open the pool. The next time 1856 * the pool is opened, the first thing we'll do -- before any 1857 * user data is modified -- is mark every vdev dirty so that 1858 * all labels will be brought up to date. We flush the new labels 1859 * to disk to ensure that all odd-label updates are committed to 1860 * stable storage before the next transaction group begins. 1861 */ 1862 if ((error = vdev_label_sync_list(spa, 1, txg, flags)) != 0) { 1863 if ((flags & ZIO_FLAG_TRYHARD) != 0) { 1864 zfs_dbgmsg("vdev_label_sync_list() returned error %d " 1865 "for pool '%s' when syncing out the odd labels of " 1866 "dirty vdevs", error, spa_name(spa)); 1867 } 1868 goto retry; 1869 } 1870 1871 return (0); 1872 } 1873