1168404Spjd/* 2168404Spjd * CDDL HEADER START 3168404Spjd * 4168404Spjd * The contents of this file are subject to the terms of the 5168404Spjd * Common Development and Distribution License (the "License"). 6168404Spjd * You may not use this file except in compliance with the License. 7168404Spjd * 8168404Spjd * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9168404Spjd * or http://www.opensolaris.org/os/licensing. 10168404Spjd * See the License for the specific language governing permissions 11168404Spjd * and limitations under the License. 12168404Spjd * 13168404Spjd * When distributing Covered Code, include this CDDL HEADER in each 14168404Spjd * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15168404Spjd * If applicable, add the following below this CDDL HEADER, with the 16168404Spjd * fields enclosed by brackets "[]" replaced with your own identifying 17168404Spjd * information: Portions Copyright [yyyy] [name of copyright owner] 18168404Spjd * 19168404Spjd * CDDL HEADER END 20168404Spjd */ 21168404Spjd/* 22219089Spjd * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 23168404Spjd * Use is subject to license terms. 24168404Spjd */ 25168404Spjd 26236839Smm/* 27249643Smm * Copyright (c) 2013 by Delphix. All rights reserved. 28236839Smm */ 29236839Smm 30168404Spjd#include <sys/zfs_context.h> 31168404Spjd#include <sys/spa.h> 32168404Spjd#include <sys/vdev_impl.h> 33168404Spjd#include <sys/zio.h> 34168404Spjd#include <sys/fs/zfs.h> 35168404Spjd 36168404Spjd/* 37168404Spjd * Virtual device vector for mirroring. 38168404Spjd */ 39168404Spjd 40168404Spjdtypedef struct mirror_child { 41168404Spjd vdev_t *mc_vd; 42168404Spjd uint64_t mc_offset; 43168404Spjd int mc_error; 44185029Spjd uint8_t mc_tried; 45185029Spjd uint8_t mc_skipped; 46185029Spjd uint8_t mc_speculative; 47168404Spjd} mirror_child_t; 48168404Spjd 49168404Spjdtypedef struct mirror_map { 50168404Spjd int mm_children; 51168404Spjd int mm_replacing; 52168404Spjd int mm_preferred; 53168404Spjd int mm_root; 54168404Spjd mirror_child_t mm_child[1]; 55168404Spjd} mirror_map_t; 56168404Spjd 57168404Spjdint vdev_mirror_shift = 21; 58168404Spjd 59185029Spjdstatic void 60185029Spjdvdev_mirror_map_free(zio_t *zio) 61185029Spjd{ 62185029Spjd mirror_map_t *mm = zio->io_vsd; 63185029Spjd 64185029Spjd kmem_free(mm, offsetof(mirror_map_t, mm_child[mm->mm_children])); 65185029Spjd} 66185029Spjd 67219089Spjdstatic const zio_vsd_ops_t vdev_mirror_vsd_ops = { 68219089Spjd vdev_mirror_map_free, 69219089Spjd zio_vsd_default_cksum_report 70219089Spjd}; 71219089Spjd 72168404Spjdstatic mirror_map_t * 73168404Spjdvdev_mirror_map_alloc(zio_t *zio) 74168404Spjd{ 75168404Spjd mirror_map_t *mm = NULL; 76168404Spjd mirror_child_t *mc; 77168404Spjd vdev_t *vd = zio->io_vd; 78168404Spjd int c, d; 79168404Spjd 80168404Spjd if (vd == NULL) { 81168404Spjd dva_t *dva = zio->io_bp->blk_dva; 82168404Spjd spa_t *spa = zio->io_spa; 83168404Spjd 84168404Spjd c = BP_GET_NDVAS(zio->io_bp); 85168404Spjd 86168404Spjd mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); 87168404Spjd mm->mm_children = c; 88168404Spjd mm->mm_replacing = B_FALSE; 89168404Spjd mm->mm_preferred = spa_get_random(c); 90168404Spjd mm->mm_root = B_TRUE; 91168404Spjd 92168404Spjd /* 93168404Spjd * Check the other, lower-index DVAs to see if they're on 94168404Spjd * the same vdev as the child we picked. If they are, use 95168404Spjd * them since they are likely to have been allocated from 96168404Spjd * the primary metaslab in use at the time, and hence are 97168404Spjd * more likely to have locality with single-copy data. 98168404Spjd */ 99168404Spjd for (c = mm->mm_preferred, d = c - 1; d >= 0; d--) { 100168404Spjd if (DVA_GET_VDEV(&dva[d]) == DVA_GET_VDEV(&dva[c])) 101168404Spjd mm->mm_preferred = d; 102168404Spjd } 103168404Spjd 104168404Spjd for (c = 0; c < mm->mm_children; c++) { 105168404Spjd mc = &mm->mm_child[c]; 106168404Spjd 107168404Spjd mc->mc_vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[c])); 108168404Spjd mc->mc_offset = DVA_GET_OFFSET(&dva[c]); 109168404Spjd } 110168404Spjd } else { 111168404Spjd c = vd->vdev_children; 112168404Spjd 113168404Spjd mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); 114168404Spjd mm->mm_children = c; 115168404Spjd mm->mm_replacing = (vd->vdev_ops == &vdev_replacing_ops || 116168404Spjd vd->vdev_ops == &vdev_spare_ops); 117168404Spjd mm->mm_preferred = mm->mm_replacing ? 0 : 118168404Spjd (zio->io_offset >> vdev_mirror_shift) % c; 119168404Spjd mm->mm_root = B_FALSE; 120168404Spjd 121168404Spjd for (c = 0; c < mm->mm_children; c++) { 122168404Spjd mc = &mm->mm_child[c]; 123168404Spjd mc->mc_vd = vd->vdev_child[c]; 124168404Spjd mc->mc_offset = zio->io_offset; 125168404Spjd } 126168404Spjd } 127168404Spjd 128168404Spjd zio->io_vsd = mm; 129219089Spjd zio->io_vsd_ops = &vdev_mirror_vsd_ops; 130168404Spjd return (mm); 131168404Spjd} 132168404Spjd 133168404Spjdstatic int 134236839Smmvdev_mirror_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, 135262081Savg uint64_t *logical_ashift, uint64_t *physical_ashift) 136168404Spjd{ 137168404Spjd int numerrors = 0; 138219089Spjd int lasterror = 0; 139168404Spjd 140168404Spjd if (vd->vdev_children == 0) { 141168404Spjd vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; 142249643Smm return (SET_ERROR(EINVAL)); 143168404Spjd } 144168404Spjd 145219089Spjd vdev_open_children(vd); 146168404Spjd 147219089Spjd for (int c = 0; c < vd->vdev_children; c++) { 148219089Spjd vdev_t *cvd = vd->vdev_child[c]; 149219089Spjd 150219089Spjd if (cvd->vdev_open_error) { 151219089Spjd lasterror = cvd->vdev_open_error; 152168404Spjd numerrors++; 153168404Spjd continue; 154168404Spjd } 155168404Spjd 156168404Spjd *asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1; 157236839Smm *max_asize = MIN(*max_asize - 1, cvd->vdev_max_asize - 1) + 1; 158262081Savg *logical_ashift = MAX(*logical_ashift, cvd->vdev_ashift); 159262081Savg *physical_ashift = MAX(*physical_ashift, 160262081Savg cvd->vdev_physical_ashift); 161168404Spjd } 162168404Spjd 163168404Spjd if (numerrors == vd->vdev_children) { 164168404Spjd vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; 165168404Spjd return (lasterror); 166168404Spjd } 167168404Spjd 168168404Spjd return (0); 169168404Spjd} 170168404Spjd 171168404Spjdstatic void 172168404Spjdvdev_mirror_close(vdev_t *vd) 173168404Spjd{ 174219089Spjd for (int c = 0; c < vd->vdev_children; c++) 175168404Spjd vdev_close(vd->vdev_child[c]); 176168404Spjd} 177168404Spjd 178168404Spjdstatic void 179168404Spjdvdev_mirror_child_done(zio_t *zio) 180168404Spjd{ 181168404Spjd mirror_child_t *mc = zio->io_private; 182168404Spjd 183168404Spjd mc->mc_error = zio->io_error; 184168404Spjd mc->mc_tried = 1; 185168404Spjd mc->mc_skipped = 0; 186168404Spjd} 187168404Spjd 188168404Spjdstatic void 189168404Spjdvdev_mirror_scrub_done(zio_t *zio) 190168404Spjd{ 191168404Spjd mirror_child_t *mc = zio->io_private; 192168404Spjd 193168404Spjd if (zio->io_error == 0) { 194209962Smm zio_t *pio; 195209962Smm 196209962Smm mutex_enter(&zio->io_lock); 197209962Smm while ((pio = zio_walk_parents(zio)) != NULL) { 198209962Smm mutex_enter(&pio->io_lock); 199209962Smm ASSERT3U(zio->io_size, >=, pio->io_size); 200209962Smm bcopy(zio->io_data, pio->io_data, pio->io_size); 201209962Smm mutex_exit(&pio->io_lock); 202209962Smm } 203209962Smm mutex_exit(&zio->io_lock); 204168404Spjd } 205168404Spjd 206168404Spjd zio_buf_free(zio->io_data, zio->io_size); 207168404Spjd 208168404Spjd mc->mc_error = zio->io_error; 209168404Spjd mc->mc_tried = 1; 210168404Spjd mc->mc_skipped = 0; 211168404Spjd} 212168404Spjd 213168404Spjd/* 214168404Spjd * Try to find a child whose DTL doesn't contain the block we want to read. 215168404Spjd * If we can't, try the read on any vdev we haven't already tried. 216168404Spjd */ 217168404Spjdstatic int 218168404Spjdvdev_mirror_child_select(zio_t *zio) 219168404Spjd{ 220168404Spjd mirror_map_t *mm = zio->io_vsd; 221168404Spjd mirror_child_t *mc; 222168404Spjd uint64_t txg = zio->io_txg; 223168404Spjd int i, c; 224168404Spjd 225219089Spjd ASSERT(zio->io_bp == NULL || BP_PHYSICAL_BIRTH(zio->io_bp) == txg); 226168404Spjd 227168404Spjd /* 228168404Spjd * Try to find a child whose DTL doesn't contain the block to read. 229168404Spjd * If a child is known to be completely inaccessible (indicated by 230185029Spjd * vdev_readable() returning B_FALSE), don't even try. 231168404Spjd */ 232168404Spjd for (i = 0, c = mm->mm_preferred; i < mm->mm_children; i++, c++) { 233168404Spjd if (c >= mm->mm_children) 234168404Spjd c = 0; 235168404Spjd mc = &mm->mm_child[c]; 236168404Spjd if (mc->mc_tried || mc->mc_skipped) 237168404Spjd continue; 238185029Spjd if (!vdev_readable(mc->mc_vd)) { 239249643Smm mc->mc_error = SET_ERROR(ENXIO); 240168404Spjd mc->mc_tried = 1; /* don't even try */ 241168404Spjd mc->mc_skipped = 1; 242168404Spjd continue; 243168404Spjd } 244209962Smm if (!vdev_dtl_contains(mc->mc_vd, DTL_MISSING, txg, 1)) 245168404Spjd return (c); 246249643Smm mc->mc_error = SET_ERROR(ESTALE); 247168404Spjd mc->mc_skipped = 1; 248185029Spjd mc->mc_speculative = 1; 249168404Spjd } 250168404Spjd 251168404Spjd /* 252168404Spjd * Every device is either missing or has this txg in its DTL. 253168404Spjd * Look for any child we haven't already tried before giving up. 254168404Spjd */ 255168404Spjd for (c = 0; c < mm->mm_children; c++) 256168404Spjd if (!mm->mm_child[c].mc_tried) 257168404Spjd return (c); 258168404Spjd 259168404Spjd /* 260168404Spjd * Every child failed. There's no place left to look. 261168404Spjd */ 262168404Spjd return (-1); 263168404Spjd} 264168404Spjd 265185029Spjdstatic int 266168404Spjdvdev_mirror_io_start(zio_t *zio) 267168404Spjd{ 268168404Spjd mirror_map_t *mm; 269168404Spjd mirror_child_t *mc; 270168404Spjd int c, children; 271168404Spjd 272168404Spjd mm = vdev_mirror_map_alloc(zio); 273168404Spjd 274168404Spjd if (zio->io_type == ZIO_TYPE_READ) { 275168404Spjd if ((zio->io_flags & ZIO_FLAG_SCRUB) && !mm->mm_replacing) { 276168404Spjd /* 277168404Spjd * For scrubbing reads we need to allocate a read 278168404Spjd * buffer for each child and issue reads to all 279168404Spjd * children. If any child succeeds, it will copy its 280168404Spjd * data into zio->io_data in vdev_mirror_scrub_done. 281168404Spjd */ 282168404Spjd for (c = 0; c < mm->mm_children; c++) { 283168404Spjd mc = &mm->mm_child[c]; 284168404Spjd zio_nowait(zio_vdev_child_io(zio, zio->io_bp, 285168404Spjd mc->mc_vd, mc->mc_offset, 286168404Spjd zio_buf_alloc(zio->io_size), zio->io_size, 287185029Spjd zio->io_type, zio->io_priority, 0, 288168404Spjd vdev_mirror_scrub_done, mc)); 289168404Spjd } 290185029Spjd return (ZIO_PIPELINE_CONTINUE); 291168404Spjd } 292168404Spjd /* 293168404Spjd * For normal reads just pick one child. 294168404Spjd */ 295168404Spjd c = vdev_mirror_child_select(zio); 296168404Spjd children = (c >= 0); 297168404Spjd } else { 298251419Ssmh ASSERT(zio->io_type == ZIO_TYPE_WRITE || 299251419Ssmh zio->io_type == ZIO_TYPE_FREE); 300168404Spjd 301168404Spjd /* 302251419Ssmh * Writes and frees go to all children. 303168404Spjd */ 304209962Smm c = 0; 305209962Smm children = mm->mm_children; 306168404Spjd } 307168404Spjd 308168404Spjd while (children--) { 309168404Spjd mc = &mm->mm_child[c]; 310168404Spjd zio_nowait(zio_vdev_child_io(zio, zio->io_bp, 311185029Spjd mc->mc_vd, mc->mc_offset, zio->io_data, zio->io_size, 312185029Spjd zio->io_type, zio->io_priority, 0, 313185029Spjd vdev_mirror_child_done, mc)); 314168404Spjd c++; 315168404Spjd } 316168404Spjd 317185029Spjd return (ZIO_PIPELINE_CONTINUE); 318168404Spjd} 319168404Spjd 320185029Spjdstatic int 321185029Spjdvdev_mirror_worst_error(mirror_map_t *mm) 322185029Spjd{ 323185029Spjd int error[2] = { 0, 0 }; 324185029Spjd 325185029Spjd for (int c = 0; c < mm->mm_children; c++) { 326185029Spjd mirror_child_t *mc = &mm->mm_child[c]; 327185029Spjd int s = mc->mc_speculative; 328185029Spjd error[s] = zio_worst_error(error[s], mc->mc_error); 329185029Spjd } 330185029Spjd 331185029Spjd return (error[0] ? error[0] : error[1]); 332185029Spjd} 333185029Spjd 334168404Spjdstatic void 335168404Spjdvdev_mirror_io_done(zio_t *zio) 336168404Spjd{ 337168404Spjd mirror_map_t *mm = zio->io_vsd; 338168404Spjd mirror_child_t *mc; 339168404Spjd int c; 340168404Spjd int good_copies = 0; 341168404Spjd int unexpected_errors = 0; 342168404Spjd 343168404Spjd for (c = 0; c < mm->mm_children; c++) { 344168404Spjd mc = &mm->mm_child[c]; 345168404Spjd 346168404Spjd if (mc->mc_error) { 347168404Spjd if (!mc->mc_skipped) 348168404Spjd unexpected_errors++; 349185029Spjd } else if (mc->mc_tried) { 350185029Spjd good_copies++; 351168404Spjd } 352168404Spjd } 353168404Spjd 354168404Spjd if (zio->io_type == ZIO_TYPE_WRITE) { 355168404Spjd /* 356168404Spjd * XXX -- for now, treat partial writes as success. 357185029Spjd * 358185029Spjd * Now that we support write reallocation, it would be better 359185029Spjd * to treat partial failure as real failure unless there are 360185029Spjd * no non-degraded top-level vdevs left, and not update DTLs 361185029Spjd * if we intend to reallocate. 362168404Spjd */ 363168404Spjd /* XXPOLICY */ 364185029Spjd if (good_copies != mm->mm_children) { 365185029Spjd /* 366185029Spjd * Always require at least one good copy. 367185029Spjd * 368185029Spjd * For ditto blocks (io_vd == NULL), require 369185029Spjd * all copies to be good. 370185029Spjd * 371185029Spjd * XXX -- for replacing vdevs, there's no great answer. 372185029Spjd * If the old device is really dead, we may not even 373185029Spjd * be able to access it -- so we only want to 374185029Spjd * require good writes to the new device. But if 375185029Spjd * the new device turns out to be flaky, we want 376185029Spjd * to be able to detach it -- which requires all 377185029Spjd * writes to the old device to have succeeded. 378185029Spjd */ 379185029Spjd if (good_copies == 0 || zio->io_vd == NULL) 380185029Spjd zio->io_error = vdev_mirror_worst_error(mm); 381185029Spjd } 382168404Spjd return; 383251419Ssmh } else if (zio->io_type == ZIO_TYPE_FREE) { 384251419Ssmh return; 385168404Spjd } 386168404Spjd 387168404Spjd ASSERT(zio->io_type == ZIO_TYPE_READ); 388168404Spjd 389168404Spjd /* 390168404Spjd * If we don't have a good copy yet, keep trying other children. 391168404Spjd */ 392168404Spjd /* XXPOLICY */ 393168404Spjd if (good_copies == 0 && (c = vdev_mirror_child_select(zio)) != -1) { 394168404Spjd ASSERT(c >= 0 && c < mm->mm_children); 395168404Spjd mc = &mm->mm_child[c]; 396168404Spjd zio_vdev_io_redone(zio); 397168404Spjd zio_nowait(zio_vdev_child_io(zio, zio->io_bp, 398168404Spjd mc->mc_vd, mc->mc_offset, zio->io_data, zio->io_size, 399185029Spjd ZIO_TYPE_READ, zio->io_priority, 0, 400168404Spjd vdev_mirror_child_done, mc)); 401168404Spjd return; 402168404Spjd } 403168404Spjd 404168404Spjd /* XXPOLICY */ 405185029Spjd if (good_copies == 0) { 406185029Spjd zio->io_error = vdev_mirror_worst_error(mm); 407168404Spjd ASSERT(zio->io_error != 0); 408185029Spjd } 409168404Spjd 410209962Smm if (good_copies && spa_writeable(zio->io_spa) && 411168404Spjd (unexpected_errors || 412168404Spjd (zio->io_flags & ZIO_FLAG_RESILVER) || 413168404Spjd ((zio->io_flags & ZIO_FLAG_SCRUB) && mm->mm_replacing))) { 414168404Spjd /* 415168404Spjd * Use the good data we have in hand to repair damaged children. 416168404Spjd */ 417168404Spjd for (c = 0; c < mm->mm_children; c++) { 418168404Spjd /* 419168404Spjd * Don't rewrite known good children. 420168404Spjd * Not only is it unnecessary, it could 421168404Spjd * actually be harmful: if the system lost 422168404Spjd * power while rewriting the only good copy, 423168404Spjd * there would be no good copies left! 424168404Spjd */ 425168404Spjd mc = &mm->mm_child[c]; 426168404Spjd 427168404Spjd if (mc->mc_error == 0) { 428168404Spjd if (mc->mc_tried) 429168404Spjd continue; 430168404Spjd if (!(zio->io_flags & ZIO_FLAG_SCRUB) && 431209962Smm !vdev_dtl_contains(mc->mc_vd, DTL_PARTIAL, 432168404Spjd zio->io_txg, 1)) 433168404Spjd continue; 434249643Smm mc->mc_error = SET_ERROR(ESTALE); 435168404Spjd } 436168404Spjd 437185029Spjd zio_nowait(zio_vdev_child_io(zio, zio->io_bp, 438185029Spjd mc->mc_vd, mc->mc_offset, 439185029Spjd zio->io_data, zio->io_size, 440260764Savg ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE, 441209962Smm ZIO_FLAG_IO_REPAIR | (unexpected_errors ? 442209962Smm ZIO_FLAG_SELF_HEAL : 0), NULL, NULL)); 443168404Spjd } 444168404Spjd } 445168404Spjd} 446168404Spjd 447168404Spjdstatic void 448168404Spjdvdev_mirror_state_change(vdev_t *vd, int faulted, int degraded) 449168404Spjd{ 450168404Spjd if (faulted == vd->vdev_children) 451168404Spjd vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, 452168404Spjd VDEV_AUX_NO_REPLICAS); 453168404Spjd else if (degraded + faulted != 0) 454168404Spjd vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); 455168404Spjd else 456168404Spjd vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); 457168404Spjd} 458168404Spjd 459168404Spjdvdev_ops_t vdev_mirror_ops = { 460168404Spjd vdev_mirror_open, 461168404Spjd vdev_mirror_close, 462168404Spjd vdev_default_asize, 463168404Spjd vdev_mirror_io_start, 464168404Spjd vdev_mirror_io_done, 465168404Spjd vdev_mirror_state_change, 466219089Spjd NULL, 467219089Spjd NULL, 468168404Spjd VDEV_TYPE_MIRROR, /* name of this vdev type */ 469168404Spjd B_FALSE /* not a leaf vdev */ 470168404Spjd}; 471168404Spjd 472168404Spjdvdev_ops_t vdev_replacing_ops = { 473168404Spjd vdev_mirror_open, 474168404Spjd vdev_mirror_close, 475168404Spjd vdev_default_asize, 476168404Spjd vdev_mirror_io_start, 477168404Spjd vdev_mirror_io_done, 478168404Spjd vdev_mirror_state_change, 479219089Spjd NULL, 480219089Spjd NULL, 481168404Spjd VDEV_TYPE_REPLACING, /* name of this vdev type */ 482168404Spjd B_FALSE /* not a leaf vdev */ 483168404Spjd}; 484168404Spjd 485168404Spjdvdev_ops_t vdev_spare_ops = { 486168404Spjd vdev_mirror_open, 487168404Spjd vdev_mirror_close, 488168404Spjd vdev_default_asize, 489168404Spjd vdev_mirror_io_start, 490168404Spjd vdev_mirror_io_done, 491168404Spjd vdev_mirror_state_change, 492219089Spjd NULL, 493219089Spjd NULL, 494168404Spjd VDEV_TYPE_SPARE, /* name of this vdev type */ 495168404Spjd B_FALSE /* not a leaf vdev */ 496168404Spjd}; 497