1fa9e4066Sahrens /* 2fa9e4066Sahrens * CDDL HEADER START 3fa9e4066Sahrens * 4fa9e4066Sahrens * The contents of this file are subject to the terms of the 5441d80aaSlling * Common Development and Distribution License (the "License"). 6441d80aaSlling * You may not use this file except in compliance with the License. 7fa9e4066Sahrens * 8fa9e4066Sahrens * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9fa9e4066Sahrens * or http://www.opensolaris.org/os/licensing. 10fa9e4066Sahrens * See the License for the specific language governing permissions 11fa9e4066Sahrens * and limitations under the License. 12fa9e4066Sahrens * 13fa9e4066Sahrens * When distributing Covered Code, include this CDDL HEADER in each 14fa9e4066Sahrens * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15fa9e4066Sahrens * If applicable, add the following below this CDDL HEADER, with the 16fa9e4066Sahrens * fields enclosed by brackets "[]" replaced with your own identifying 17fa9e4066Sahrens * information: Portions Copyright [yyyy] [name of copyright owner] 18fa9e4066Sahrens * 19fa9e4066Sahrens * CDDL HEADER END 20fa9e4066Sahrens */ 21fa9e4066Sahrens /* 22*39c23413Seschrock * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23fa9e4066Sahrens * Use is subject to license terms. 24fa9e4066Sahrens */ 25fa9e4066Sahrens 26fa9e4066Sahrens #pragma ident "%Z%%M% %I% %E% SMI" 27fa9e4066Sahrens 28fa9e4066Sahrens /* 29fa9e4066Sahrens * Virtual Device Labels 30fa9e4066Sahrens * --------------------- 31fa9e4066Sahrens * 32fa9e4066Sahrens * The vdev label serves several distinct purposes: 33fa9e4066Sahrens * 34fa9e4066Sahrens * 1. Uniquely identify this device as part of a ZFS pool and confirm its 35fa9e4066Sahrens * identity within the pool. 36fa9e4066Sahrens * 37fa9e4066Sahrens * 2. Verify that all the devices given in a configuration are present 38fa9e4066Sahrens * within the pool. 39fa9e4066Sahrens * 40fa9e4066Sahrens * 3. Determine the uberblock for the pool. 41fa9e4066Sahrens * 42fa9e4066Sahrens * 4. In case of an import operation, determine the configuration of the 43fa9e4066Sahrens * toplevel vdev of which it is a part. 44fa9e4066Sahrens * 45fa9e4066Sahrens * 5. If an import operation cannot find all the devices in the pool, 46fa9e4066Sahrens * provide enough information to the administrator to determine which 47fa9e4066Sahrens * devices are missing. 48fa9e4066Sahrens * 49fa9e4066Sahrens * It is important to note that while the kernel is responsible for writing the 50fa9e4066Sahrens * label, it only consumes the information in the first three cases. The 51fa9e4066Sahrens * latter information is only consumed in userland when determining the 52fa9e4066Sahrens * configuration to import a pool. 53fa9e4066Sahrens * 54fa9e4066Sahrens * 55fa9e4066Sahrens * Label Organization 56fa9e4066Sahrens * ------------------ 57fa9e4066Sahrens * 58fa9e4066Sahrens * Before describing the contents of the label, it's important to understand how 59fa9e4066Sahrens * the labels are written and updated with respect to the uberblock. 60fa9e4066Sahrens * 61fa9e4066Sahrens * When the pool configuration is altered, either because it was newly created 62fa9e4066Sahrens * or a device was added, we want to update all the labels such that we can deal 63fa9e4066Sahrens * with fatal failure at any point. To this end, each disk has two labels which 64fa9e4066Sahrens * are updated before and after the uberblock is synced. Assuming we have 65fa9e4066Sahrens * labels and an uberblock with the following transacation groups: 66fa9e4066Sahrens * 67fa9e4066Sahrens * L1 UB L2 68fa9e4066Sahrens * +------+ +------+ +------+ 69fa9e4066Sahrens * | | | | | | 70fa9e4066Sahrens * | t10 | | t10 | | t10 | 71fa9e4066Sahrens * | | | | | | 72fa9e4066Sahrens * +------+ +------+ +------+ 73fa9e4066Sahrens * 74fa9e4066Sahrens * In this stable state, the labels and the uberblock were all updated within 75fa9e4066Sahrens * the same transaction group (10). Each label is mirrored and checksummed, so 76fa9e4066Sahrens * that we can detect when we fail partway through writing the label. 77fa9e4066Sahrens * 78fa9e4066Sahrens * In order to identify which labels are valid, the labels are written in the 79fa9e4066Sahrens * following manner: 80fa9e4066Sahrens * 81fa9e4066Sahrens * 1. For each vdev, update 'L1' to the new label 82fa9e4066Sahrens * 2. Update the uberblock 83fa9e4066Sahrens * 3. For each vdev, update 'L2' to the new label 84fa9e4066Sahrens * 85fa9e4066Sahrens * Given arbitrary failure, we can determine the correct label to use based on 86fa9e4066Sahrens * the transaction group. If we fail after updating L1 but before updating the 87fa9e4066Sahrens * UB, we will notice that L1's transaction group is greater than the uberblock, 88fa9e4066Sahrens * so L2 must be valid. If we fail after writing the uberblock but before 89fa9e4066Sahrens * writing L2, we will notice that L2's transaction group is less than L1, and 90fa9e4066Sahrens * therefore L1 is valid. 91fa9e4066Sahrens * 92fa9e4066Sahrens * Another added complexity is that not every label is updated when the config 93fa9e4066Sahrens * is synced. If we add a single device, we do not want to have to re-write 94fa9e4066Sahrens * every label for every device in the pool. This means that both L1 and L2 may 95fa9e4066Sahrens * be older than the pool uberblock, because the necessary information is stored 96fa9e4066Sahrens * on another vdev. 97fa9e4066Sahrens * 98fa9e4066Sahrens * 99fa9e4066Sahrens * On-disk Format 100fa9e4066Sahrens * -------------- 101fa9e4066Sahrens * 102fa9e4066Sahrens * The vdev label consists of two distinct parts, and is wrapped within the 103fa9e4066Sahrens * vdev_label_t structure. The label includes 8k of padding to permit legacy 104fa9e4066Sahrens * VTOC disk labels, but is otherwise ignored. 105fa9e4066Sahrens * 106fa9e4066Sahrens * The first half of the label is a packed nvlist which contains pool wide 107fa9e4066Sahrens * properties, per-vdev properties, and configuration information. It is 108fa9e4066Sahrens * described in more detail below. 109fa9e4066Sahrens * 110fa9e4066Sahrens * The latter half of the label consists of a redundant array of uberblocks. 111fa9e4066Sahrens * These uberblocks are updated whenever a transaction group is committed, 112fa9e4066Sahrens * or when the configuration is updated. When a pool is loaded, we scan each 113fa9e4066Sahrens * vdev for the 'best' uberblock. 114fa9e4066Sahrens * 115fa9e4066Sahrens * 116fa9e4066Sahrens * Configuration Information 117fa9e4066Sahrens * ------------------------- 118fa9e4066Sahrens * 119fa9e4066Sahrens * The nvlist describing the pool and vdev contains the following elements: 120fa9e4066Sahrens * 121fa9e4066Sahrens * version ZFS on-disk version 122fa9e4066Sahrens * name Pool name 123fa9e4066Sahrens * state Pool state 124fa9e4066Sahrens * txg Transaction group in which this label was written 125fa9e4066Sahrens * pool_guid Unique identifier for this pool 126fa9e4066Sahrens * vdev_tree An nvlist describing vdev tree. 127fa9e4066Sahrens * 128fa9e4066Sahrens * Each leaf device label also contains the following: 129fa9e4066Sahrens * 130fa9e4066Sahrens * top_guid Unique ID for top-level vdev in which this is contained 131fa9e4066Sahrens * guid Unique ID for the leaf vdev 132fa9e4066Sahrens * 133fa9e4066Sahrens * The 'vs' configuration follows the format described in 'spa_config.c'. 134fa9e4066Sahrens */ 135fa9e4066Sahrens 136fa9e4066Sahrens #include <sys/zfs_context.h> 137fa9e4066Sahrens #include <sys/spa.h> 138fa9e4066Sahrens #include <sys/spa_impl.h> 139fa9e4066Sahrens #include <sys/dmu.h> 140fa9e4066Sahrens #include <sys/zap.h> 141fa9e4066Sahrens #include <sys/vdev.h> 142fa9e4066Sahrens #include <sys/vdev_impl.h> 143fa9e4066Sahrens #include <sys/uberblock_impl.h> 144fa9e4066Sahrens #include <sys/metaslab.h> 145fa9e4066Sahrens #include <sys/zio.h> 146fa9e4066Sahrens #include <sys/fs/zfs.h> 147fa9e4066Sahrens 148fa9e4066Sahrens /* 149fa9e4066Sahrens * Basic routines to read and write from a vdev label. 150fa9e4066Sahrens * Used throughout the rest of this file. 151fa9e4066Sahrens */ 152fa9e4066Sahrens uint64_t 153fa9e4066Sahrens vdev_label_offset(uint64_t psize, int l, uint64_t offset) 154fa9e4066Sahrens { 155ecc2d604Sbonwick ASSERT(offset < sizeof (vdev_label_t)); 156ecc2d604Sbonwick 157fa9e4066Sahrens return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 158fa9e4066Sahrens 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); 159fa9e4066Sahrens } 160fa9e4066Sahrens 161fa9e4066Sahrens static void 162fa9e4066Sahrens vdev_label_read(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, 163fa9e4066Sahrens uint64_t size, zio_done_func_t *done, void *private) 164fa9e4066Sahrens { 165fa9e4066Sahrens ASSERT(vd->vdev_children == 0); 166fa9e4066Sahrens 167fa9e4066Sahrens zio_nowait(zio_read_phys(zio, vd, 168fa9e4066Sahrens vdev_label_offset(vd->vdev_psize, l, offset), 169fa9e4066Sahrens size, buf, ZIO_CHECKSUM_LABEL, done, private, 170ea8dc4b6Seschrock ZIO_PRIORITY_SYNC_READ, 171ea8dc4b6Seschrock ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE)); 172fa9e4066Sahrens } 173fa9e4066Sahrens 174fa9e4066Sahrens static void 175fa9e4066Sahrens vdev_label_write(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, 176fa9e4066Sahrens uint64_t size, zio_done_func_t *done, void *private) 177fa9e4066Sahrens { 178fa9e4066Sahrens ASSERT(vd->vdev_children == 0); 179fa9e4066Sahrens 180fa9e4066Sahrens zio_nowait(zio_write_phys(zio, vd, 181fa9e4066Sahrens vdev_label_offset(vd->vdev_psize, l, offset), 182fa9e4066Sahrens size, buf, ZIO_CHECKSUM_LABEL, done, private, 183ea8dc4b6Seschrock ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL)); 184fa9e4066Sahrens } 185fa9e4066Sahrens 186fa9e4066Sahrens /* 187fa9e4066Sahrens * Generate the nvlist representing this vdev's config. 188fa9e4066Sahrens */ 189fa9e4066Sahrens nvlist_t * 19099653d4eSeschrock vdev_config_generate(spa_t *spa, vdev_t *vd, boolean_t getstats, 19199653d4eSeschrock boolean_t isspare) 192fa9e4066Sahrens { 193fa9e4066Sahrens nvlist_t *nv = NULL; 194fa9e4066Sahrens 195ea8dc4b6Seschrock VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 196fa9e4066Sahrens 197fa9e4066Sahrens VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_TYPE, 198fa9e4066Sahrens vd->vdev_ops->vdev_op_type) == 0); 19999653d4eSeschrock if (!isspare) 20099653d4eSeschrock VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ID, vd->vdev_id) 20199653d4eSeschrock == 0); 202fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, vd->vdev_guid) == 0); 203fa9e4066Sahrens 204fa9e4066Sahrens if (vd->vdev_path != NULL) 205fa9e4066Sahrens VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_PATH, 206fa9e4066Sahrens vd->vdev_path) == 0); 207fa9e4066Sahrens 208fa9e4066Sahrens if (vd->vdev_devid != NULL) 209fa9e4066Sahrens VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, 210fa9e4066Sahrens vd->vdev_devid) == 0); 211fa9e4066Sahrens 21299653d4eSeschrock if (vd->vdev_nparity != 0) { 21399653d4eSeschrock ASSERT(strcmp(vd->vdev_ops->vdev_op_type, 21499653d4eSeschrock VDEV_TYPE_RAIDZ) == 0); 21599653d4eSeschrock 21699653d4eSeschrock /* 21799653d4eSeschrock * Make sure someone hasn't managed to sneak a fancy new vdev 21899653d4eSeschrock * into a crufty old storage pool. 21999653d4eSeschrock */ 22099653d4eSeschrock ASSERT(vd->vdev_nparity == 1 || 22199653d4eSeschrock (vd->vdev_nparity == 2 && 22299653d4eSeschrock spa_version(spa) >= ZFS_VERSION_RAID6)); 22399653d4eSeschrock 22499653d4eSeschrock /* 22599653d4eSeschrock * Note that we'll add the nparity tag even on storage pools 22699653d4eSeschrock * that only support a single parity device -- older software 22799653d4eSeschrock * will just ignore it. 22899653d4eSeschrock */ 22999653d4eSeschrock VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, 23099653d4eSeschrock vd->vdev_nparity) == 0); 23199653d4eSeschrock } 23299653d4eSeschrock 233afefbcddSeschrock if (vd->vdev_wholedisk != -1ULL) 234afefbcddSeschrock VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, 235afefbcddSeschrock vd->vdev_wholedisk) == 0); 236afefbcddSeschrock 237ea8dc4b6Seschrock if (vd->vdev_not_present) 238ea8dc4b6Seschrock VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, 1) == 0); 239ea8dc4b6Seschrock 24099653d4eSeschrock if (vd->vdev_isspare) 24199653d4eSeschrock VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1) == 0); 24299653d4eSeschrock 24399653d4eSeschrock if (!isspare && vd == vd->vdev_top) { 244fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY, 245fa9e4066Sahrens vd->vdev_ms_array) == 0); 246fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT, 247fa9e4066Sahrens vd->vdev_ms_shift) == 0); 248fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASHIFT, 249fa9e4066Sahrens vd->vdev_ashift) == 0); 250fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASIZE, 251fa9e4066Sahrens vd->vdev_asize) == 0); 252fa9e4066Sahrens } 253fa9e4066Sahrens 254fa9e4066Sahrens if (vd->vdev_dtl.smo_object != 0) 255fa9e4066Sahrens VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_DTL, 256fa9e4066Sahrens vd->vdev_dtl.smo_object) == 0); 257fa9e4066Sahrens 258fa9e4066Sahrens if (getstats) { 259fa9e4066Sahrens vdev_stat_t vs; 260fa9e4066Sahrens vdev_get_stats(vd, &vs); 261fa9e4066Sahrens VERIFY(nvlist_add_uint64_array(nv, ZPOOL_CONFIG_STATS, 262fa9e4066Sahrens (uint64_t *)&vs, sizeof (vs) / sizeof (uint64_t)) == 0); 263fa9e4066Sahrens } 264fa9e4066Sahrens 265fa9e4066Sahrens if (!vd->vdev_ops->vdev_op_leaf) { 266fa9e4066Sahrens nvlist_t **child; 267fa9e4066Sahrens int c; 268fa9e4066Sahrens 269fa9e4066Sahrens child = kmem_alloc(vd->vdev_children * sizeof (nvlist_t *), 270fa9e4066Sahrens KM_SLEEP); 271fa9e4066Sahrens 272fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 27399653d4eSeschrock child[c] = vdev_config_generate(spa, vd->vdev_child[c], 27499653d4eSeschrock getstats, isspare); 275fa9e4066Sahrens 276fa9e4066Sahrens VERIFY(nvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, 277fa9e4066Sahrens child, vd->vdev_children) == 0); 278fa9e4066Sahrens 279fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 280fa9e4066Sahrens nvlist_free(child[c]); 281fa9e4066Sahrens 282fa9e4066Sahrens kmem_free(child, vd->vdev_children * sizeof (nvlist_t *)); 283441d80aaSlling 284441d80aaSlling } else { 285ecc2d604Sbonwick if (vd->vdev_offline && !vd->vdev_tmpoffline) 286441d80aaSlling VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_OFFLINE, 287ecc2d604Sbonwick B_TRUE) == 0); 288ecc2d604Sbonwick else 289441d80aaSlling (void) nvlist_remove(nv, ZPOOL_CONFIG_OFFLINE, 290ecc2d604Sbonwick DATA_TYPE_UINT64); 291fa9e4066Sahrens } 292fa9e4066Sahrens 293fa9e4066Sahrens return (nv); 294fa9e4066Sahrens } 295fa9e4066Sahrens 296fa9e4066Sahrens nvlist_t * 297fa9e4066Sahrens vdev_label_read_config(vdev_t *vd) 298fa9e4066Sahrens { 2990373e76bSbonwick spa_t *spa = vd->vdev_spa; 300fa9e4066Sahrens nvlist_t *config = NULL; 301fa9e4066Sahrens vdev_phys_t *vp; 302fa9e4066Sahrens zio_t *zio; 303fa9e4066Sahrens int l; 304fa9e4066Sahrens 3050373e76bSbonwick ASSERT(spa_config_held(spa, RW_READER)); 3060373e76bSbonwick 307fa9e4066Sahrens if (vdev_is_dead(vd)) 308fa9e4066Sahrens return (NULL); 309fa9e4066Sahrens 310fa9e4066Sahrens vp = zio_buf_alloc(sizeof (vdev_phys_t)); 311fa9e4066Sahrens 312fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) { 313fa9e4066Sahrens 3140373e76bSbonwick zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL | 315ea8dc4b6Seschrock ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CONFIG_HELD); 316fa9e4066Sahrens 317fa9e4066Sahrens vdev_label_read(zio, vd, l, vp, 318fa9e4066Sahrens offsetof(vdev_label_t, vl_vdev_phys), 319fa9e4066Sahrens sizeof (vdev_phys_t), NULL, NULL); 320fa9e4066Sahrens 321fa9e4066Sahrens if (zio_wait(zio) == 0 && 322fa9e4066Sahrens nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist), 323ea8dc4b6Seschrock &config, 0) == 0) 324fa9e4066Sahrens break; 325fa9e4066Sahrens 326fa9e4066Sahrens if (config != NULL) { 327fa9e4066Sahrens nvlist_free(config); 328fa9e4066Sahrens config = NULL; 329fa9e4066Sahrens } 330fa9e4066Sahrens } 331fa9e4066Sahrens 332fa9e4066Sahrens zio_buf_free(vp, sizeof (vdev_phys_t)); 333fa9e4066Sahrens 334fa9e4066Sahrens return (config); 335fa9e4066Sahrens } 336fa9e4066Sahrens 337*39c23413Seschrock /* 338*39c23413Seschrock * Determine if a device is in use. The 'spare_guid' parameter will be filled 339*39c23413Seschrock * in with the device guid if this spare is active elsewhere on the system. 340*39c23413Seschrock */ 341*39c23413Seschrock static boolean_t 342*39c23413Seschrock vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason, 343*39c23413Seschrock uint64_t *spare_guid) 344*39c23413Seschrock { 345*39c23413Seschrock spa_t *spa = vd->vdev_spa; 346*39c23413Seschrock uint64_t state, pool_guid, device_guid, txg, spare_pool; 347*39c23413Seschrock uint64_t vdtxg = 0; 348*39c23413Seschrock nvlist_t *label; 349*39c23413Seschrock 350*39c23413Seschrock if (spare_guid) 351*39c23413Seschrock *spare_guid = 0ULL; 352*39c23413Seschrock 353*39c23413Seschrock /* 354*39c23413Seschrock * Read the label, if any, and perform some basic sanity checks. 355*39c23413Seschrock */ 356*39c23413Seschrock if ((label = vdev_label_read_config(vd)) == NULL) 357*39c23413Seschrock return (B_FALSE); 358*39c23413Seschrock 359*39c23413Seschrock (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG, 360*39c23413Seschrock &vdtxg); 361*39c23413Seschrock 362*39c23413Seschrock if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, 363*39c23413Seschrock &state) != 0 || 364*39c23413Seschrock nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, 365*39c23413Seschrock &device_guid) != 0) { 366*39c23413Seschrock nvlist_free(label); 367*39c23413Seschrock return (B_FALSE); 368*39c23413Seschrock } 369*39c23413Seschrock 370*39c23413Seschrock if (state != POOL_STATE_SPARE && 371*39c23413Seschrock (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID, 372*39c23413Seschrock &pool_guid) != 0 || 373*39c23413Seschrock nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG, 374*39c23413Seschrock &txg) != 0)) { 375*39c23413Seschrock nvlist_free(label); 376*39c23413Seschrock return (B_FALSE); 377*39c23413Seschrock } 378*39c23413Seschrock 379*39c23413Seschrock nvlist_free(label); 380*39c23413Seschrock 381*39c23413Seschrock /* 382*39c23413Seschrock * Check to see if this device indeed belongs to the pool it claims to 383*39c23413Seschrock * be a part of. The only way this is allowed is if the device is a hot 384*39c23413Seschrock * spare (which we check for later on). 385*39c23413Seschrock */ 386*39c23413Seschrock if (state != POOL_STATE_SPARE && 387*39c23413Seschrock !spa_guid_exists(pool_guid, device_guid) && 388*39c23413Seschrock !spa_spare_exists(device_guid, NULL)) 389*39c23413Seschrock return (B_FALSE); 390*39c23413Seschrock 391*39c23413Seschrock /* 392*39c23413Seschrock * If the transaction group is zero, then this an initialized (but 393*39c23413Seschrock * unused) label. This is only an error if the create transaction 394*39c23413Seschrock * on-disk is the same as the one we're using now, in which case the 395*39c23413Seschrock * user has attempted to add the same vdev multiple times in the same 396*39c23413Seschrock * transaction. 397*39c23413Seschrock */ 398*39c23413Seschrock if (state != POOL_STATE_SPARE && txg == 0 && vdtxg == crtxg) 399*39c23413Seschrock return (B_TRUE); 400*39c23413Seschrock 401*39c23413Seschrock /* 402*39c23413Seschrock * Check to see if this is a spare device. We do an explicit check for 403*39c23413Seschrock * spa_has_spare() here because it may be on our pending list of spares 404*39c23413Seschrock * to add. 405*39c23413Seschrock */ 406*39c23413Seschrock if (spa_spare_exists(device_guid, &spare_pool) || 407*39c23413Seschrock spa_has_spare(spa, device_guid)) { 408*39c23413Seschrock if (spare_guid) 409*39c23413Seschrock *spare_guid = device_guid; 410*39c23413Seschrock 411*39c23413Seschrock switch (reason) { 412*39c23413Seschrock case VDEV_LABEL_CREATE: 413*39c23413Seschrock return (B_TRUE); 414*39c23413Seschrock 415*39c23413Seschrock case VDEV_LABEL_REPLACE: 416*39c23413Seschrock return (!spa_has_spare(spa, device_guid) || 417*39c23413Seschrock spare_pool != 0ULL); 418*39c23413Seschrock 419*39c23413Seschrock case VDEV_LABEL_SPARE: 420*39c23413Seschrock return (spa_has_spare(spa, device_guid)); 421*39c23413Seschrock } 422*39c23413Seschrock } 423*39c23413Seschrock 424*39c23413Seschrock /* 425*39c23413Seschrock * If the device is marked ACTIVE, then this device is in use by another 426*39c23413Seschrock * pool on the system. 427*39c23413Seschrock */ 428*39c23413Seschrock return (state == POOL_STATE_ACTIVE); 429*39c23413Seschrock } 430*39c23413Seschrock 431*39c23413Seschrock /* 432*39c23413Seschrock * Initialize a vdev label. We check to make sure each leaf device is not in 433*39c23413Seschrock * use, and writable. We put down an initial label which we will later 434*39c23413Seschrock * overwrite with a complete label. Note that it's important to do this 435*39c23413Seschrock * sequentially, not in parallel, so that we catch cases of multiple use of the 436*39c23413Seschrock * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with 437*39c23413Seschrock * itself. 438*39c23413Seschrock */ 439*39c23413Seschrock int 440*39c23413Seschrock vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason) 441fa9e4066Sahrens { 442fa9e4066Sahrens spa_t *spa = vd->vdev_spa; 443fa9e4066Sahrens nvlist_t *label; 444fa9e4066Sahrens vdev_phys_t *vp; 445fa9e4066Sahrens vdev_boot_header_t *vb; 446ecc2d604Sbonwick uberblock_t *ub; 447fa9e4066Sahrens zio_t *zio; 448fa9e4066Sahrens int l, c, n; 449fa9e4066Sahrens char *buf; 450fa9e4066Sahrens size_t buflen; 451fa9e4066Sahrens int error; 452*39c23413Seschrock uint64_t spare_guid; 453fa9e4066Sahrens 4540373e76bSbonwick ASSERT(spa_config_held(spa, RW_WRITER)); 4550373e76bSbonwick 456fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 457*39c23413Seschrock if ((error = vdev_label_init(vd->vdev_child[c], 458*39c23413Seschrock crtxg, reason)) != 0) 459fa9e4066Sahrens return (error); 460fa9e4066Sahrens 461fa9e4066Sahrens if (!vd->vdev_ops->vdev_op_leaf) 462fa9e4066Sahrens return (0); 463fa9e4066Sahrens 464fa9e4066Sahrens /* 465*39c23413Seschrock * Dead vdevs cannot be initialized. 466fa9e4066Sahrens */ 467fa9e4066Sahrens if (vdev_is_dead(vd)) 468fa9e4066Sahrens return (EIO); 469fa9e4066Sahrens 470fa9e4066Sahrens /* 471*39c23413Seschrock * Determine if the vdev is in use. 472fa9e4066Sahrens */ 473*39c23413Seschrock if (reason != VDEV_LABEL_REMOVE && 474*39c23413Seschrock vdev_inuse(vd, crtxg, reason, &spare_guid)) 475*39c23413Seschrock return (EBUSY); 476*39c23413Seschrock 477*39c23413Seschrock ASSERT(reason != VDEV_LABEL_REMOVE || 478*39c23413Seschrock vdev_inuse(vd, crtxg, reason, NULL)); 479*39c23413Seschrock 480*39c23413Seschrock /* 481*39c23413Seschrock * If this is a request to add or replace a spare that is in use 482*39c23413Seschrock * elsewhere on the system, then we must update the guid (which was 483*39c23413Seschrock * initialized to a random value) to reflect the actual GUID (which is 484*39c23413Seschrock * shared between multiple pools). 485*39c23413Seschrock */ 486*39c23413Seschrock if (reason != VDEV_LABEL_REMOVE && spare_guid != 0ULL) { 487*39c23413Seschrock vdev_t *pvd = vd->vdev_parent; 488*39c23413Seschrock 489*39c23413Seschrock for (; pvd != NULL; pvd = pvd->vdev_parent) { 490*39c23413Seschrock pvd->vdev_guid_sum -= vd->vdev_guid; 491*39c23413Seschrock pvd->vdev_guid_sum += spare_guid; 492fa9e4066Sahrens } 49399653d4eSeschrock 494*39c23413Seschrock vd->vdev_guid = vd->vdev_guid_sum = spare_guid; 495*39c23413Seschrock 49699653d4eSeschrock /* 497*39c23413Seschrock * If this is a replacement, then we want to fallthrough to the 498*39c23413Seschrock * rest of the code. If we're adding a spare, then it's already 499*39c23413Seschrock * labelled appropriately and we can just return. 50099653d4eSeschrock */ 501*39c23413Seschrock if (reason == VDEV_LABEL_SPARE) 502*39c23413Seschrock return (0); 503*39c23413Seschrock ASSERT(reason == VDEV_LABEL_REPLACE); 504fa9e4066Sahrens } 505fa9e4066Sahrens 506fa9e4066Sahrens /* 507*39c23413Seschrock * Initialize its label. 508fa9e4066Sahrens */ 509fa9e4066Sahrens vp = zio_buf_alloc(sizeof (vdev_phys_t)); 510fa9e4066Sahrens bzero(vp, sizeof (vdev_phys_t)); 511fa9e4066Sahrens 512fa9e4066Sahrens /* 513fa9e4066Sahrens * Generate a label describing the pool and our top-level vdev. 514fa9e4066Sahrens * We mark it as being from txg 0 to indicate that it's not 515fa9e4066Sahrens * really part of an active pool just yet. The labels will 516fa9e4066Sahrens * be written again with a meaningful txg by spa_sync(). 517fa9e4066Sahrens */ 518*39c23413Seschrock if (reason == VDEV_LABEL_SPARE || 519*39c23413Seschrock (reason == VDEV_LABEL_REMOVE && vd->vdev_isspare)) { 520*39c23413Seschrock /* 521*39c23413Seschrock * For inactive hot spares, we generate a special label that 522*39c23413Seschrock * identifies as a mutually shared hot spare. We write the 523*39c23413Seschrock * label if we are adding a hot spare, or if we are removing an 524*39c23413Seschrock * active hot spare (in which case we want to revert the 525*39c23413Seschrock * labels). 526*39c23413Seschrock */ 52799653d4eSeschrock VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); 52899653d4eSeschrock 52999653d4eSeschrock VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, 53099653d4eSeschrock spa_version(spa)) == 0); 53199653d4eSeschrock VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, 53299653d4eSeschrock POOL_STATE_SPARE) == 0); 53399653d4eSeschrock VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, 53499653d4eSeschrock vd->vdev_guid) == 0); 53599653d4eSeschrock } else { 53699653d4eSeschrock label = spa_config_generate(spa, vd, 0ULL, B_FALSE); 53799653d4eSeschrock 53899653d4eSeschrock /* 53999653d4eSeschrock * Add our creation time. This allows us to detect multiple 54099653d4eSeschrock * vdev uses as described above, and automatically expires if we 54199653d4eSeschrock * fail. 54299653d4eSeschrock */ 54399653d4eSeschrock VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_CREATE_TXG, 54499653d4eSeschrock crtxg) == 0); 54599653d4eSeschrock } 546fa9e4066Sahrens 547fa9e4066Sahrens buf = vp->vp_nvlist; 548fa9e4066Sahrens buflen = sizeof (vp->vp_nvlist); 549fa9e4066Sahrens 550ea8dc4b6Seschrock if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) != 0) { 551fa9e4066Sahrens nvlist_free(label); 552fa9e4066Sahrens zio_buf_free(vp, sizeof (vdev_phys_t)); 553fa9e4066Sahrens return (EINVAL); 554fa9e4066Sahrens } 555fa9e4066Sahrens 556fa9e4066Sahrens /* 557fa9e4066Sahrens * Initialize boot block header. 558fa9e4066Sahrens */ 559fa9e4066Sahrens vb = zio_buf_alloc(sizeof (vdev_boot_header_t)); 560fa9e4066Sahrens bzero(vb, sizeof (vdev_boot_header_t)); 561fa9e4066Sahrens vb->vb_magic = VDEV_BOOT_MAGIC; 562fa9e4066Sahrens vb->vb_version = VDEV_BOOT_VERSION; 563fa9e4066Sahrens vb->vb_offset = VDEV_BOOT_OFFSET; 564fa9e4066Sahrens vb->vb_size = VDEV_BOOT_SIZE; 565fa9e4066Sahrens 566fa9e4066Sahrens /* 567fa9e4066Sahrens * Initialize uberblock template. 568fa9e4066Sahrens */ 569ecc2d604Sbonwick ub = zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)); 570ecc2d604Sbonwick bzero(ub, VDEV_UBERBLOCK_SIZE(vd)); 571ecc2d604Sbonwick *ub = spa->spa_uberblock; 572ecc2d604Sbonwick ub->ub_txg = 0; 573fa9e4066Sahrens 574fa9e4066Sahrens /* 575fa9e4066Sahrens * Write everything in parallel. 576fa9e4066Sahrens */ 577fa9e4066Sahrens zio = zio_root(spa, NULL, NULL, 578fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 579fa9e4066Sahrens 580fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) { 581fa9e4066Sahrens 582fa9e4066Sahrens vdev_label_write(zio, vd, l, vp, 583fa9e4066Sahrens offsetof(vdev_label_t, vl_vdev_phys), 584fa9e4066Sahrens sizeof (vdev_phys_t), NULL, NULL); 585fa9e4066Sahrens 586fa9e4066Sahrens vdev_label_write(zio, vd, l, vb, 587fa9e4066Sahrens offsetof(vdev_label_t, vl_boot_header), 588fa9e4066Sahrens sizeof (vdev_boot_header_t), NULL, NULL); 589fa9e4066Sahrens 590ecc2d604Sbonwick for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { 591ecc2d604Sbonwick vdev_label_write(zio, vd, l, ub, 592ecc2d604Sbonwick VDEV_UBERBLOCK_OFFSET(vd, n), 593ecc2d604Sbonwick VDEV_UBERBLOCK_SIZE(vd), NULL, NULL); 594fa9e4066Sahrens } 595fa9e4066Sahrens } 596fa9e4066Sahrens 597fa9e4066Sahrens error = zio_wait(zio); 598fa9e4066Sahrens 599fa9e4066Sahrens nvlist_free(label); 600ecc2d604Sbonwick zio_buf_free(ub, VDEV_UBERBLOCK_SIZE(vd)); 601fa9e4066Sahrens zio_buf_free(vb, sizeof (vdev_boot_header_t)); 602fa9e4066Sahrens zio_buf_free(vp, sizeof (vdev_phys_t)); 603fa9e4066Sahrens 604*39c23413Seschrock /* 605*39c23413Seschrock * If this vdev hasn't been previously identified as a spare, then we 606*39c23413Seschrock * mark it as such only if a) we are labelling it as a spare, or b) it 607*39c23413Seschrock * exists as a spare elsewhere in the system. 608*39c23413Seschrock */ 609*39c23413Seschrock if (error == 0 && !vd->vdev_isspare && 610*39c23413Seschrock (reason == VDEV_LABEL_SPARE || 611*39c23413Seschrock spa_spare_exists(vd->vdev_guid, NULL))) 612*39c23413Seschrock spa_spare_add(vd); 61399653d4eSeschrock 614*39c23413Seschrock return (error); 61599653d4eSeschrock } 61699653d4eSeschrock 617fa9e4066Sahrens /* 618fa9e4066Sahrens * ========================================================================== 619fa9e4066Sahrens * uberblock load/sync 620fa9e4066Sahrens * ========================================================================== 621fa9e4066Sahrens */ 622fa9e4066Sahrens 623fa9e4066Sahrens /* 624fa9e4066Sahrens * Consider the following situation: txg is safely synced to disk. We've 625fa9e4066Sahrens * written the first uberblock for txg + 1, and then we lose power. When we 626fa9e4066Sahrens * come back up, we fail to see the uberblock for txg + 1 because, say, 627fa9e4066Sahrens * it was on a mirrored device and the replica to which we wrote txg + 1 628fa9e4066Sahrens * is now offline. If we then make some changes and sync txg + 1, and then 629fa9e4066Sahrens * the missing replica comes back, then for a new seconds we'll have two 630fa9e4066Sahrens * conflicting uberblocks on disk with the same txg. The solution is simple: 631fa9e4066Sahrens * among uberblocks with equal txg, choose the one with the latest timestamp. 632fa9e4066Sahrens */ 633fa9e4066Sahrens static int 634fa9e4066Sahrens vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) 635fa9e4066Sahrens { 636fa9e4066Sahrens if (ub1->ub_txg < ub2->ub_txg) 637fa9e4066Sahrens return (-1); 638fa9e4066Sahrens if (ub1->ub_txg > ub2->ub_txg) 639fa9e4066Sahrens return (1); 640fa9e4066Sahrens 641fa9e4066Sahrens if (ub1->ub_timestamp < ub2->ub_timestamp) 642fa9e4066Sahrens return (-1); 643fa9e4066Sahrens if (ub1->ub_timestamp > ub2->ub_timestamp) 644fa9e4066Sahrens return (1); 645fa9e4066Sahrens 646fa9e4066Sahrens return (0); 647fa9e4066Sahrens } 648fa9e4066Sahrens 649fa9e4066Sahrens static void 650fa9e4066Sahrens vdev_uberblock_load_done(zio_t *zio) 651fa9e4066Sahrens { 652ecc2d604Sbonwick uberblock_t *ub = zio->io_data; 653fa9e4066Sahrens uberblock_t *ubbest = zio->io_private; 654fa9e4066Sahrens spa_t *spa = zio->io_spa; 655fa9e4066Sahrens 656ecc2d604Sbonwick ASSERT3U(zio->io_size, ==, VDEV_UBERBLOCK_SIZE(zio->io_vd)); 657fa9e4066Sahrens 658ea8dc4b6Seschrock if (zio->io_error == 0 && uberblock_verify(ub) == 0) { 659fa9e4066Sahrens mutex_enter(&spa->spa_uberblock_lock); 660fa9e4066Sahrens if (vdev_uberblock_compare(ub, ubbest) > 0) 661fa9e4066Sahrens *ubbest = *ub; 662fa9e4066Sahrens mutex_exit(&spa->spa_uberblock_lock); 663fa9e4066Sahrens } 664fa9e4066Sahrens 665fa9e4066Sahrens zio_buf_free(zio->io_data, zio->io_size); 666fa9e4066Sahrens } 667fa9e4066Sahrens 668fa9e4066Sahrens void 669fa9e4066Sahrens vdev_uberblock_load(zio_t *zio, vdev_t *vd, uberblock_t *ubbest) 670fa9e4066Sahrens { 671fa9e4066Sahrens int l, c, n; 672fa9e4066Sahrens 673fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 674fa9e4066Sahrens vdev_uberblock_load(zio, vd->vdev_child[c], ubbest); 675fa9e4066Sahrens 676fa9e4066Sahrens if (!vd->vdev_ops->vdev_op_leaf) 677fa9e4066Sahrens return; 678fa9e4066Sahrens 679fa9e4066Sahrens if (vdev_is_dead(vd)) 680fa9e4066Sahrens return; 681fa9e4066Sahrens 682fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) { 683ecc2d604Sbonwick for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { 684fa9e4066Sahrens vdev_label_read(zio, vd, l, 685ecc2d604Sbonwick zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)), 686ecc2d604Sbonwick VDEV_UBERBLOCK_OFFSET(vd, n), 687ecc2d604Sbonwick VDEV_UBERBLOCK_SIZE(vd), 688fa9e4066Sahrens vdev_uberblock_load_done, ubbest); 689fa9e4066Sahrens } 690fa9e4066Sahrens } 691fa9e4066Sahrens } 692fa9e4066Sahrens 693fa9e4066Sahrens /* 694fa9e4066Sahrens * Write the uberblock to both labels of all leaves of the specified vdev. 6950373e76bSbonwick * We only get credit for writes to known-visible vdevs; see spa_vdev_add(). 696fa9e4066Sahrens */ 697fa9e4066Sahrens static void 698fa9e4066Sahrens vdev_uberblock_sync_done(zio_t *zio) 699fa9e4066Sahrens { 700fa9e4066Sahrens uint64_t *good_writes = zio->io_root->io_private; 701fa9e4066Sahrens 7020373e76bSbonwick if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0) 703fa9e4066Sahrens atomic_add_64(good_writes, 1); 704fa9e4066Sahrens } 705fa9e4066Sahrens 706fa9e4066Sahrens static void 707ecc2d604Sbonwick vdev_uberblock_sync(zio_t *zio, uberblock_t *ub, vdev_t *vd, uint64_t txg) 708fa9e4066Sahrens { 709fa9e4066Sahrens int l, c, n; 710fa9e4066Sahrens 711fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 712ecc2d604Sbonwick vdev_uberblock_sync(zio, ub, vd->vdev_child[c], txg); 713fa9e4066Sahrens 714fa9e4066Sahrens if (!vd->vdev_ops->vdev_op_leaf) 715fa9e4066Sahrens return; 716fa9e4066Sahrens 717fa9e4066Sahrens if (vdev_is_dead(vd)) 718fa9e4066Sahrens return; 719fa9e4066Sahrens 720ecc2d604Sbonwick n = txg & (VDEV_UBERBLOCK_COUNT(vd) - 1); 721fa9e4066Sahrens 722ecc2d604Sbonwick ASSERT(ub->ub_txg == txg); 723fa9e4066Sahrens 724fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) 725ecc2d604Sbonwick vdev_label_write(zio, vd, l, ub, 726ecc2d604Sbonwick VDEV_UBERBLOCK_OFFSET(vd, n), 727ecc2d604Sbonwick VDEV_UBERBLOCK_SIZE(vd), 728ecc2d604Sbonwick vdev_uberblock_sync_done, NULL); 729fa9e4066Sahrens 730fa9e4066Sahrens dprintf("vdev %s in txg %llu\n", vdev_description(vd), txg); 731fa9e4066Sahrens } 732fa9e4066Sahrens 733fa9e4066Sahrens static int 734ecc2d604Sbonwick vdev_uberblock_sync_tree(spa_t *spa, uberblock_t *ub, vdev_t *vd, uint64_t txg) 735fa9e4066Sahrens { 736ecc2d604Sbonwick uberblock_t *ubbuf; 737ecc2d604Sbonwick size_t size = vd->vdev_top ? VDEV_UBERBLOCK_SIZE(vd) : SPA_MAXBLOCKSIZE; 738fa9e4066Sahrens uint64_t *good_writes; 739fa9e4066Sahrens zio_t *zio; 740fa9e4066Sahrens int error; 741fa9e4066Sahrens 742ecc2d604Sbonwick ubbuf = zio_buf_alloc(size); 743ecc2d604Sbonwick bzero(ubbuf, size); 744ecc2d604Sbonwick *ubbuf = *ub; 745fa9e4066Sahrens 746fa9e4066Sahrens good_writes = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); 747fa9e4066Sahrens 748fa9e4066Sahrens zio = zio_root(spa, NULL, good_writes, 749fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 750fa9e4066Sahrens 751ecc2d604Sbonwick vdev_uberblock_sync(zio, ubbuf, vd, txg); 752fa9e4066Sahrens 753fa9e4066Sahrens error = zio_wait(zio); 754fa9e4066Sahrens 755fa9e4066Sahrens if (error && *good_writes != 0) { 756fa9e4066Sahrens dprintf("partial success: good_writes = %llu\n", *good_writes); 757fa9e4066Sahrens error = 0; 758fa9e4066Sahrens } 759fa9e4066Sahrens 760fa9e4066Sahrens /* 761fa9e4066Sahrens * It's possible to have no good writes and no error if every vdev is in 762fa9e4066Sahrens * the CANT_OPEN state. 763fa9e4066Sahrens */ 764fa9e4066Sahrens if (*good_writes == 0 && error == 0) 765fa9e4066Sahrens error = EIO; 766fa9e4066Sahrens 767fa9e4066Sahrens kmem_free(good_writes, sizeof (uint64_t)); 768ecc2d604Sbonwick zio_buf_free(ubbuf, size); 769fa9e4066Sahrens 770fa9e4066Sahrens return (error); 771fa9e4066Sahrens } 772fa9e4066Sahrens 773fa9e4066Sahrens /* 774fa9e4066Sahrens * Sync out an individual vdev. 775fa9e4066Sahrens */ 776fa9e4066Sahrens static void 777fa9e4066Sahrens vdev_sync_label_done(zio_t *zio) 778fa9e4066Sahrens { 779fa9e4066Sahrens uint64_t *good_writes = zio->io_root->io_private; 780fa9e4066Sahrens 781fa9e4066Sahrens if (zio->io_error == 0) 782fa9e4066Sahrens atomic_add_64(good_writes, 1); 783fa9e4066Sahrens } 784fa9e4066Sahrens 785fa9e4066Sahrens static void 786fa9e4066Sahrens vdev_sync_label(zio_t *zio, vdev_t *vd, int l, uint64_t txg) 787fa9e4066Sahrens { 788fa9e4066Sahrens nvlist_t *label; 789fa9e4066Sahrens vdev_phys_t *vp; 790fa9e4066Sahrens char *buf; 791fa9e4066Sahrens size_t buflen; 792fa9e4066Sahrens int c; 793fa9e4066Sahrens 794fa9e4066Sahrens for (c = 0; c < vd->vdev_children; c++) 795fa9e4066Sahrens vdev_sync_label(zio, vd->vdev_child[c], l, txg); 796fa9e4066Sahrens 797fa9e4066Sahrens if (!vd->vdev_ops->vdev_op_leaf) 798fa9e4066Sahrens return; 799fa9e4066Sahrens 800fa9e4066Sahrens if (vdev_is_dead(vd)) 801fa9e4066Sahrens return; 802fa9e4066Sahrens 803fa9e4066Sahrens /* 804fa9e4066Sahrens * Generate a label describing the top-level config to which we belong. 805fa9e4066Sahrens */ 8060373e76bSbonwick label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE); 807fa9e4066Sahrens 808fa9e4066Sahrens vp = zio_buf_alloc(sizeof (vdev_phys_t)); 809fa9e4066Sahrens bzero(vp, sizeof (vdev_phys_t)); 810fa9e4066Sahrens 811fa9e4066Sahrens buf = vp->vp_nvlist; 812fa9e4066Sahrens buflen = sizeof (vp->vp_nvlist); 813fa9e4066Sahrens 814ea8dc4b6Seschrock if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) == 0) 815fa9e4066Sahrens vdev_label_write(zio, vd, l, vp, 816fa9e4066Sahrens offsetof(vdev_label_t, vl_vdev_phys), sizeof (vdev_phys_t), 817fa9e4066Sahrens vdev_sync_label_done, NULL); 818fa9e4066Sahrens 819fa9e4066Sahrens zio_buf_free(vp, sizeof (vdev_phys_t)); 820fa9e4066Sahrens nvlist_free(label); 821fa9e4066Sahrens 822fa9e4066Sahrens dprintf("%s label %d txg %llu\n", vdev_description(vd), l, txg); 823fa9e4066Sahrens } 824fa9e4066Sahrens 825fa9e4066Sahrens static int 826fa9e4066Sahrens vdev_sync_labels(vdev_t *vd, int l, uint64_t txg) 827fa9e4066Sahrens { 828fa9e4066Sahrens uint64_t *good_writes; 829fa9e4066Sahrens zio_t *zio; 830fa9e4066Sahrens int error; 831fa9e4066Sahrens 832fa9e4066Sahrens ASSERT(vd == vd->vdev_top); 833fa9e4066Sahrens 834fa9e4066Sahrens good_writes = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); 835fa9e4066Sahrens 836fa9e4066Sahrens zio = zio_root(vd->vdev_spa, NULL, good_writes, 837fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 838fa9e4066Sahrens 839fa9e4066Sahrens /* 840fa9e4066Sahrens * Recursively kick off writes to all labels. 841fa9e4066Sahrens */ 842fa9e4066Sahrens vdev_sync_label(zio, vd, l, txg); 843fa9e4066Sahrens 844fa9e4066Sahrens error = zio_wait(zio); 845fa9e4066Sahrens 846fa9e4066Sahrens if (error && *good_writes != 0) { 847fa9e4066Sahrens dprintf("partial success: good_writes = %llu\n", *good_writes); 848fa9e4066Sahrens error = 0; 849fa9e4066Sahrens } 850fa9e4066Sahrens 851fa9e4066Sahrens if (*good_writes == 0 && error == 0) 852fa9e4066Sahrens error = ENODEV; 853fa9e4066Sahrens 854fa9e4066Sahrens kmem_free(good_writes, sizeof (uint64_t)); 855fa9e4066Sahrens 856fa9e4066Sahrens return (error); 857fa9e4066Sahrens } 858fa9e4066Sahrens 859fa9e4066Sahrens /* 860fa9e4066Sahrens * Sync the entire vdev configuration. 861fa9e4066Sahrens * 862fa9e4066Sahrens * The order of operations is carefully crafted to ensure that 863fa9e4066Sahrens * if the system panics or loses power at any time, the state on disk 864fa9e4066Sahrens * is still transactionally consistent. The in-line comments below 865fa9e4066Sahrens * describe the failure semantics at each stage. 866fa9e4066Sahrens * 867fa9e4066Sahrens * Moreover, it is designed to be idempotent: if spa_sync_labels() fails 868fa9e4066Sahrens * at any time, you can just call it again, and it will resume its work. 869fa9e4066Sahrens */ 870fa9e4066Sahrens int 8710373e76bSbonwick vdev_config_sync(vdev_t *uvd, uint64_t txg) 872fa9e4066Sahrens { 8730373e76bSbonwick spa_t *spa = uvd->vdev_spa; 874fa9e4066Sahrens uberblock_t *ub = &spa->spa_uberblock; 875fa9e4066Sahrens vdev_t *rvd = spa->spa_root_vdev; 8760373e76bSbonwick vdev_t *vd; 877fa9e4066Sahrens zio_t *zio; 878f65ea9b9Sbonwick int l, error; 879fa9e4066Sahrens 880fa9e4066Sahrens ASSERT(ub->ub_txg <= txg); 881fa9e4066Sahrens 882fa9e4066Sahrens /* 883fa9e4066Sahrens * If this isn't a resync due to I/O errors, and nothing changed 884fa9e4066Sahrens * in this transaction group, and the vdev configuration hasn't changed, 8850373e76bSbonwick * then there's nothing to do. 886fa9e4066Sahrens */ 887fa9e4066Sahrens if (ub->ub_txg < txg && uberblock_update(ub, rvd, txg) == B_FALSE && 888fa9e4066Sahrens list_is_empty(&spa->spa_dirty_list)) { 889fa9e4066Sahrens dprintf("nothing to sync in %s in txg %llu\n", 890fa9e4066Sahrens spa_name(spa), txg); 891fa9e4066Sahrens return (0); 892fa9e4066Sahrens } 893fa9e4066Sahrens 894fa9e4066Sahrens if (txg > spa_freeze_txg(spa)) 895fa9e4066Sahrens return (0); 896fa9e4066Sahrens 8970373e76bSbonwick ASSERT(txg <= spa->spa_final_txg); 8980373e76bSbonwick 899fa9e4066Sahrens dprintf("syncing %s txg %llu\n", spa_name(spa), txg); 900fa9e4066Sahrens 901fa9e4066Sahrens /* 902fa9e4066Sahrens * Flush the write cache of every disk that's been written to 903fa9e4066Sahrens * in this transaction group. This ensures that all blocks 904fa9e4066Sahrens * written in this txg will be committed to stable storage 905fa9e4066Sahrens * before any uberblock that references them. 906fa9e4066Sahrens */ 907fa9e4066Sahrens zio = zio_root(spa, NULL, NULL, 908fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 909fa9e4066Sahrens for (vd = txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd; 910fa9e4066Sahrens vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg))) { 911fa9e4066Sahrens zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, 912fa9e4066Sahrens NULL, NULL, ZIO_PRIORITY_NOW, 913fa9e4066Sahrens ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); 914fa9e4066Sahrens } 915fa9e4066Sahrens (void) zio_wait(zio); 916fa9e4066Sahrens 917fa9e4066Sahrens /* 918fa9e4066Sahrens * Sync out the even labels (L0, L2) for every dirty vdev. If the 919fa9e4066Sahrens * system dies in the middle of this process, that's OK: all of the 920fa9e4066Sahrens * even labels that made it to disk will be newer than any uberblock, 921fa9e4066Sahrens * and will therefore be considered invalid. The odd labels (L1, L3), 922fa9e4066Sahrens * which have not yet been touched, will still be valid. 923fa9e4066Sahrens */ 924fa9e4066Sahrens for (vd = list_head(&spa->spa_dirty_list); vd != NULL; 925fa9e4066Sahrens vd = list_next(&spa->spa_dirty_list, vd)) { 926fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) { 927fa9e4066Sahrens if (l & 1) 928fa9e4066Sahrens continue; 929fa9e4066Sahrens if ((error = vdev_sync_labels(vd, l, txg)) != 0) 930fa9e4066Sahrens return (error); 931fa9e4066Sahrens } 932fa9e4066Sahrens } 933fa9e4066Sahrens 934fa9e4066Sahrens /* 935fa9e4066Sahrens * Flush the new labels to disk. This ensures that all even-label 936fa9e4066Sahrens * updates are committed to stable storage before the uberblock update. 937fa9e4066Sahrens */ 938fa9e4066Sahrens zio = zio_root(spa, NULL, NULL, 939fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 940fa9e4066Sahrens for (vd = list_head(&spa->spa_dirty_list); vd != NULL; 941fa9e4066Sahrens vd = list_next(&spa->spa_dirty_list, vd)) { 942fa9e4066Sahrens zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, 943fa9e4066Sahrens NULL, NULL, ZIO_PRIORITY_NOW, 944fa9e4066Sahrens ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); 945fa9e4066Sahrens } 946fa9e4066Sahrens (void) zio_wait(zio); 947fa9e4066Sahrens 948fa9e4066Sahrens /* 9490373e76bSbonwick * Sync the uberblocks to all vdevs in the tree specified by uvd. 9500373e76bSbonwick * If the system dies in the middle of this step, there are two cases 9510373e76bSbonwick * to consider, and the on-disk state is consistent either way: 952fa9e4066Sahrens * 953fa9e4066Sahrens * (1) If none of the new uberblocks made it to disk, then the 954fa9e4066Sahrens * previous uberblock will be the newest, and the odd labels 955fa9e4066Sahrens * (which had not yet been touched) will be valid with respect 956fa9e4066Sahrens * to that uberblock. 957fa9e4066Sahrens * 958fa9e4066Sahrens * (2) If one or more new uberblocks made it to disk, then they 959fa9e4066Sahrens * will be the newest, and the even labels (which had all 960fa9e4066Sahrens * been successfully committed) will be valid with respect 961fa9e4066Sahrens * to the new uberblocks. 962fa9e4066Sahrens */ 963fa9e4066Sahrens if ((error = vdev_uberblock_sync_tree(spa, ub, uvd, txg)) != 0) 964fa9e4066Sahrens return (error); 965fa9e4066Sahrens 966fa9e4066Sahrens /* 967fa9e4066Sahrens * Flush the uberblocks to disk. This ensures that the odd labels 968fa9e4066Sahrens * are no longer needed (because the new uberblocks and the even 969fa9e4066Sahrens * labels are safely on disk), so it is safe to overwrite them. 970fa9e4066Sahrens */ 971fa9e4066Sahrens (void) zio_wait(zio_ioctl(NULL, spa, uvd, DKIOCFLUSHWRITECACHE, 972fa9e4066Sahrens NULL, NULL, ZIO_PRIORITY_NOW, 973fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); 974fa9e4066Sahrens 975fa9e4066Sahrens /* 976fa9e4066Sahrens * Sync out odd labels for every dirty vdev. If the system dies 977fa9e4066Sahrens * in the middle of this process, the even labels and the new 978fa9e4066Sahrens * uberblocks will suffice to open the pool. The next time 979fa9e4066Sahrens * the pool is opened, the first thing we'll do -- before any 980fa9e4066Sahrens * user data is modified -- is mark every vdev dirty so that 981fa9e4066Sahrens * all labels will be brought up to date. 982fa9e4066Sahrens */ 983fa9e4066Sahrens for (vd = list_head(&spa->spa_dirty_list); vd != NULL; 984fa9e4066Sahrens vd = list_next(&spa->spa_dirty_list, vd)) { 985fa9e4066Sahrens for (l = 0; l < VDEV_LABELS; l++) { 986fa9e4066Sahrens if ((l & 1) == 0) 987fa9e4066Sahrens continue; 988fa9e4066Sahrens if ((error = vdev_sync_labels(vd, l, txg)) != 0) 989fa9e4066Sahrens return (error); 990fa9e4066Sahrens } 991fa9e4066Sahrens } 992fa9e4066Sahrens 993fa9e4066Sahrens /* 994fa9e4066Sahrens * Flush the new labels to disk. This ensures that all odd-label 995fa9e4066Sahrens * updates are committed to stable storage before the next 996fa9e4066Sahrens * transaction group begins. 997fa9e4066Sahrens */ 998fa9e4066Sahrens zio = zio_root(spa, NULL, NULL, 999fa9e4066Sahrens ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); 1000fa9e4066Sahrens for (vd = list_head(&spa->spa_dirty_list); vd != NULL; 1001fa9e4066Sahrens vd = list_next(&spa->spa_dirty_list, vd)) { 1002fa9e4066Sahrens zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, 1003fa9e4066Sahrens NULL, NULL, ZIO_PRIORITY_NOW, 1004fa9e4066Sahrens ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); 1005fa9e4066Sahrens } 1006fa9e4066Sahrens (void) zio_wait(zio); 1007fa9e4066Sahrens 1008fa9e4066Sahrens return (0); 1009fa9e4066Sahrens } 1010