sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scrub.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/dsl_pool.h>
  27 #include <sys/dsl_dataset.h>
  28 #include <sys/dsl_prop.h>
  29 #include <sys/dsl_dir.h>
  30 #include <sys/dsl_synctask.h>
  31 #include <sys/dnode.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/dmu_objset.h>
  34 #include <sys/arc.h>
  35 #include <sys/zap.h>
  36 #include <sys/zio.h>
  37 #include <sys/zfs_context.h>
  38 #include <sys/fs/zfs.h>
  39 #include <sys/zfs_znode.h>
  40 #include <sys/spa_impl.h>
  41 #include <sys/vdev_impl.h>
  42 #include <sys/zil_impl.h>
  43
  44 typedef int (scrub_cb_t)(dsl_pool_t *, const blkptr_t *, const zbookmark_t *);
  45
  46 static scrub_cb_t dsl_pool_scrub_clean_cb;
  47 static dsl_syncfunc_t dsl_pool_scrub_cancel_sync;
  48
  49 int zfs_scrub_min_time = 1; /* scrub for at least 1 sec each txg */
  50 int zfs_resilver_min_time = 3; /* resilver for at least 3 sec each txg */
  51 boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */
  52
  53 extern int zfs_txg_timeout;
  54
  55 static scrub_cb_t *scrub_funcs[SCRUB_FUNC_NUMFUNCS] = {
  56         NULL,
  57         dsl_pool_scrub_clean_cb
  58 };
  59
  60 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
  61 {                                                       \
  62         (zb)->zb_objset = objset;                       \
  63         (zb)->zb_object = object;                       \
  64         (zb)->zb_level = level;                         \
  65         (zb)->zb_blkid = blkid;                         \
  66 }
  67
  68 /* ARGSUSED */
  69 static void
  70 dsl_pool_scrub_setup_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
  71 {
  72         dsl_pool_t *dp = arg1;
  73         enum scrub_func *funcp = arg2;
  74         dmu_object_type_t ot = 0;
  75         boolean_t complete = B_FALSE;
  76
  77         dsl_pool_scrub_cancel_sync(dp, &complete, cr, tx);
  78
  79         ASSERT(dp->dp_scrub_func == SCRUB_FUNC_NONE);
  80         ASSERT(*funcp > SCRUB_FUNC_NONE);
  81         ASSERT(*funcp < SCRUB_FUNC_NUMFUNCS);
  82
  83         dp->dp_scrub_min_txg = 0;
  84         dp->dp_scrub_max_txg = tx->tx_txg;
  85
  86         if (*funcp == SCRUB_FUNC_CLEAN) {
  87                 vdev_t *rvd = dp->dp_spa->spa_root_vdev;
  88
  89                 /* rewrite all disk labels */
  90                 vdev_config_dirty(rvd);
  91
  92                 if (vdev_resilver_needed(rvd,
  93                     &dp->dp_scrub_min_txg, &dp->dp_scrub_max_txg)) {
  94                         spa_event_notify(dp->dp_spa, NULL,
  95                             ESC_ZFS_RESILVER_START);
  96                         dp->dp_scrub_max_txg = MIN(dp->dp_scrub_max_txg,
  97                             tx->tx_txg);
  98                 }
  99
 100                 /* zero out the scrub stats in all vdev_stat_t's */
 101                 vdev_scrub_stat_update(rvd,
 102                     dp->dp_scrub_min_txg ? POOL_SCRUB_RESILVER :
 103                     POOL_SCRUB_EVERYTHING, B_FALSE);
 104
 105                 dp->dp_spa->spa_scrub_started = B_TRUE;
 106         }
 107
 108         /* back to the generic stuff */
 109
 110         if (dp->dp_blkstats == NULL) {
 111                 dp->dp_blkstats =
 112                     kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP);
 113         }
 114         bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t));
 115
 116         if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB)
 117                 ot = DMU_OT_ZAP_OTHER;
 118
 119         dp->dp_scrub_func = *funcp;
 120         dp->dp_scrub_queue_obj = zap_create(dp->dp_meta_objset,
 121             ot ? ot : DMU_OT_SCRUB_QUEUE, DMU_OT_NONE, 0, tx);
 122         bzero(&dp->dp_scrub_bookmark, sizeof (zbookmark_t));
 123         dp->dp_scrub_restart = B_FALSE;
 124         dp->dp_spa->spa_scrub_errors = 0;
 125
 126         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 127             DMU_POOL_SCRUB_FUNC, sizeof (uint32_t), 1,
 128             &dp->dp_scrub_func, tx));
 129         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 130             DMU_POOL_SCRUB_QUEUE, sizeof (uint64_t), 1,
 131             &dp->dp_scrub_queue_obj, tx));
 132         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 133             DMU_POOL_SCRUB_MIN_TXG, sizeof (uint64_t), 1,
 134             &dp->dp_scrub_min_txg, tx));
 135         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 136             DMU_POOL_SCRUB_MAX_TXG, sizeof (uint64_t), 1,
 137             &dp->dp_scrub_max_txg, tx));
 138         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 139             DMU_POOL_SCRUB_BOOKMARK, sizeof (uint64_t), 4,
 140             &dp->dp_scrub_bookmark, tx));
 141         VERIFY(0 == zap_add(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 142             DMU_POOL_SCRUB_ERRORS, sizeof (uint64_t), 1,
 143             &dp->dp_spa->spa_scrub_errors, tx));
 144
 145         spa_history_internal_log(LOG_POOL_SCRUB, dp->dp_spa, tx, cr,
 146             "func=%u mintxg=%llu maxtxg=%llu",
 147             *funcp, dp->dp_scrub_min_txg, dp->dp_scrub_max_txg);
 148 }
 149
 150 int
 151 dsl_pool_scrub_setup(dsl_pool_t *dp, enum scrub_func func)
 152 {
 153         return (dsl_sync_task_do(dp, NULL,
 154             dsl_pool_scrub_setup_sync, dp, &func, 0));
 155 }
 156
 157 /* ARGSUSED */
 158 static void
 159 dsl_pool_scrub_cancel_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
 160 {
 161         dsl_pool_t *dp = arg1;
 162         boolean_t *completep = arg2;
 163
 164         if (dp->dp_scrub_func == SCRUB_FUNC_NONE)
 165                 return;
 166
 167         mutex_enter(&dp->dp_scrub_cancel_lock);
 168
 169         if (dp->dp_scrub_restart) {
 170                 dp->dp_scrub_restart = B_FALSE;
 171                 *completep = B_FALSE;
 172         }
 173
 174         /* XXX this is scrub-clean specific */
 175         mutex_enter(&dp->dp_spa->spa_scrub_lock);
 176         while (dp->dp_spa->spa_scrub_inflight > 0) {
 177                 cv_wait(&dp->dp_spa->spa_scrub_io_cv,
 178                     &dp->dp_spa->spa_scrub_lock);
 179         }
 180         mutex_exit(&dp->dp_spa->spa_scrub_lock);
 181         dp->dp_spa->spa_scrub_started = B_FALSE;
 182         dp->dp_spa->spa_scrub_active = B_FALSE;
 183
 184         dp->dp_scrub_func = SCRUB_FUNC_NONE;
 185         VERIFY(0 == dmu_object_free(dp->dp_meta_objset,
 186             dp->dp_scrub_queue_obj, tx));
 187         dp->dp_scrub_queue_obj = 0;
 188         bzero(&dp->dp_scrub_bookmark, sizeof (zbookmark_t));
 189
 190         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 191             DMU_POOL_SCRUB_QUEUE, tx));
 192         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 193             DMU_POOL_SCRUB_MIN_TXG, tx));
 194         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 195             DMU_POOL_SCRUB_MAX_TXG, tx));
 196         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 197             DMU_POOL_SCRUB_BOOKMARK, tx));
 198         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 199             DMU_POOL_SCRUB_FUNC, tx));
 200         VERIFY(0 == zap_remove(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
 201             DMU_POOL_SCRUB_ERRORS, tx));
 202
 203         spa_history_internal_log(LOG_POOL_SCRUB_DONE, dp->dp_spa, tx, cr,
 204             "complete=%u", *completep);
 205
 206         /* below is scrub-clean specific */
 207         vdev_scrub_stat_update(dp->dp_spa->spa_root_vdev, POOL_SCRUB_NONE,
 208             *completep);
 209         /*
 210          * If the scrub/resilver completed, update all DTLs to reflect this.
 211          * Whether it succeeded or not, vacate all temporary scrub DTLs.
 212          */
 213         vdev_dtl_reassess(dp->dp_spa->spa_root_vdev, tx->tx_txg,
 214             *completep ? dp->dp_scrub_max_txg : 0, B_TRUE);
 215         if (dp->dp_scrub_min_txg && *completep)
 216                 spa_event_notify(dp->dp_spa, NULL, ESC_ZFS_RESILVER_FINISH);
 217         spa_errlog_rotate(dp->dp_spa);
 218
 219         /*
 220          * We may have finished replacing a device.
 221          * Let the async thread assess this and handle the detach.
 222          */
 223         spa_async_request(dp->dp_spa, SPA_ASYNC_RESILVER_DONE);
 224
 225         dp->dp_scrub_min_txg = dp->dp_scrub_max_txg = 0;
 226         mutex_exit(&dp->dp_scrub_cancel_lock);
 227 }
 228
 229 int
 230 dsl_pool_scrub_cancel(dsl_pool_t *dp)
 231 {
 232         boolean_t complete = B_FALSE;
 233
 234         return (dsl_sync_task_do(dp, NULL,
 235             dsl_pool_scrub_cancel_sync, dp, &complete, 3));
 236 }
 237
 238 int
 239 dsl_free(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp,
 240     zio_done_func_t *done, void *private, uint32_t arc_flags)
 241 {
 242         /*
 243          * This function will be used by bp-rewrite wad to intercept frees.
 244          */
 245         return (arc_free(pio, dp->dp_spa, txg, (blkptr_t *)bpp,
 246             done, private, arc_flags));
 247 }
 248
 249 static boolean_t
 250 bookmark_is_zero(const zbookmark_t *zb)
 251 {
 252         return (zb->zb_objset == 0 && zb->zb_object == 0 &&
 253             zb->zb_level == 0 && zb->zb_blkid == 0);
 254 }
 255
 256 /* dnp is the dnode for zb1->zb_object */
 257 static boolean_t
 258 bookmark_is_before(dnode_phys_t *dnp, const zbookmark_t *zb1,
 259     const zbookmark_t *zb2)
 260 {
 261         uint64_t zb1nextL0, zb2thisobj;
 262
 263         ASSERT(zb1->zb_objset == zb2->zb_objset);
 264         ASSERT(zb1->zb_object != -1ULL);
 265         ASSERT(zb2->zb_level == 0);
 266
 267         /*
 268          * A bookmark in the deadlist is considered to be after
 269          * everything else.
 270          */
 271         if (zb2->zb_object == -1ULL)
 272                 return (B_TRUE);
 273
 274         /* The objset_phys_t isn't before anything. */
 275         if (dnp == NULL)
 276                 return (B_FALSE);
 277
 278         zb1nextL0 = (zb1->zb_blkid + 1) <<
 279             ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT));
 280
 281         zb2thisobj = zb2->zb_object ? zb2->zb_object :
 282             zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT);
 283
 284         if (zb1->zb_object == 0) {
 285                 uint64_t nextobj = zb1nextL0 *
 286                     (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT;
 287                 return (nextobj <= zb2thisobj);
 288         }
 289
 290         if (zb1->zb_object < zb2thisobj)
 291                 return (B_TRUE);
 292         if (zb1->zb_object > zb2thisobj)
 293                 return (B_FALSE);
 294         if (zb2->zb_object == 0)
 295                 return (B_FALSE);
 296         return (zb1nextL0 <= zb2->zb_blkid);
 297 }
 298
 299 static boolean_t
 300 scrub_pause(dsl_pool_t *dp, const zbookmark_t *zb)
 301 {
 302         int elapsed_ticks;
 303         int mintime;
 304
 305         if (dp->dp_scrub_pausing)
 306                 return (B_TRUE); /* we're already pausing */
 307
 308         if (!bookmark_is_zero(&dp->dp_scrub_bookmark))
 309                 return (B_FALSE); /* we're resuming */
 310
 311         /* We only know how to resume from level-0 blocks. */
 312         if (zb->zb_level != 0)
 313                 return (B_FALSE);
 314
 315         mintime = dp->dp_scrub_isresilver ? zfs_resilver_min_time :
 316             zfs_scrub_min_time;
 317         elapsed_ticks = lbolt64 - dp->dp_scrub_start_time;
 318         if (elapsed_ticks > hz * zfs_txg_timeout ||
 319             (elapsed_ticks > hz * mintime && txg_sync_waiting(dp))) {
 320                 dprintf("pausing at %llx/%llx/%llx/%llx\n",
 321                     (longlong_t)zb->zb_objset, (longlong_t)zb->zb_object,
 322                     (longlong_t)zb->zb_level, (longlong_t)zb->zb_blkid);
 323                 dp->dp_scrub_pausing = B_TRUE;
 324                 dp->dp_scrub_bookmark = *zb;
 325                 return (B_TRUE);
 326         }
 327         return (B_FALSE);
 328 }
 329
 330 typedef struct zil_traverse_arg {
 331         dsl_pool_t      *zta_dp;
 332         zil_header_t    *zta_zh;
 333 } zil_traverse_arg_t;
 334
 335 /* ARGSUSED */
 336 static void
 337 traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
 338 {
 339         zil_traverse_arg_t *zta = arg;
 340         dsl_pool_t *dp = zta->zta_dp;
 341         zil_header_t *zh = zta->zta_zh;
 342         zbookmark_t zb;
 343
 344         if (bp->blk_birth <= dp->dp_scrub_min_txg)
 345                 return;
 346
 347         if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa))
 348                 return;
 349
 350         zb.zb_objset = zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET];
 351         zb.zb_object = 0;
 352         zb.zb_level = -1;
 353         zb.zb_blkid = bp->blk_cksum.zc_word[ZIL_ZC_SEQ];
 354         VERIFY(0 == scrub_funcs[dp->dp_scrub_func](dp, bp, &zb));
 355 }
 356
 357 /* ARGSUSED */
 358 static void
 359 traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
 360 {
 361         if (lrc->lrc_txtype == TX_WRITE) {
 362                 zil_traverse_arg_t *zta = arg;
 363                 dsl_pool_t *dp = zta->zta_dp;
 364                 zil_header_t *zh = zta->zta_zh;
 365                 lr_write_t *lr = (lr_write_t *)lrc;
 366                 blkptr_t *bp = &lr->lr_blkptr;
 367                 zbookmark_t zb;
 368
 369                 if (bp->blk_birth <= dp->dp_scrub_min_txg)
 370                         return;
 371
 372                 if (claim_txg == 0 || bp->blk_birth < claim_txg)
 373                         return;
 374
 375                 zb.zb_objset = zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET];
 376                 zb.zb_object = lr->lr_foid;
 377                 zb.zb_level = BP_GET_LEVEL(bp);
 378                 zb.zb_blkid = lr->lr_offset / BP_GET_LSIZE(bp);
 379                 VERIFY(0 == scrub_funcs[dp->dp_scrub_func](dp, bp, &zb));
 380         }
 381 }
 382
 383 static void
 384 traverse_zil(dsl_pool_t *dp, zil_header_t *zh)
 385 {
 386         uint64_t claim_txg = zh->zh_claim_txg;
 387         zil_traverse_arg_t zta = { dp, zh };
 388         zilog_t *zilog;
 389
 390         /*
 391          * We only want to visit blocks that have been claimed but not yet
 392          * replayed (or, in read-only mode, blocks that *would* be claimed).
 393          */
 394         if (claim_txg == 0 && (spa_mode & FWRITE))
 395                 return;
 396
 397         zilog = zil_alloc(dp->dp_meta_objset, zh);
 398
 399         (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, &zta,
 400             claim_txg);
 401
 402         zil_free(zilog);
 403 }
 404
 405 static void
 406 scrub_visitbp(dsl_pool_t *dp, dnode_phys_t *dnp,
 407     arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
 408 {
 409         int err;
 410         arc_buf_t *buf = NULL;
 411
 412         if (bp->blk_birth == 0)
 413                 return;
 414
 415         if (bp->blk_birth <= dp->dp_scrub_min_txg)
 416                 return;
 417
 418         if (scrub_pause(dp, zb))
 419                 return;
 420
 421         if (!bookmark_is_zero(&dp->dp_scrub_bookmark)) {
 422                 /*
 423                  * If we already visited this bp & everything below (in
 424                  * a prior txg), don't bother doing it again.
 425                  */
 426                 if (bookmark_is_before(dnp, zb, &dp->dp_scrub_bookmark))
 427                         return;
 428
 429                 /*
 430                  * If we found the block we're trying to resume from, or
 431                  * we went past it to a different object, zero it out to
 432                  * indicate that it's OK to start checking for pausing
 433                  * again.
 434                  */
 435                 if (bcmp(zb, &dp->dp_scrub_bookmark, sizeof (*zb)) == 0 ||
 436                     zb->zb_object > dp->dp_scrub_bookmark.zb_object) {
 437                         dprintf("resuming at %llx/%llx/%llx/%llx\n",
 438                             (longlong_t)zb->zb_objset,
 439                             (longlong_t)zb->zb_object,
 440                             (longlong_t)zb->zb_level,
 441                             (longlong_t)zb->zb_blkid);
 442                         bzero(&dp->dp_scrub_bookmark, sizeof (*zb));
 443                 }
 444         }
 445
 446         if (BP_GET_LEVEL(bp) > 0) {
 447                 uint32_t flags = ARC_WAIT;
 448                 int i;
 449                 blkptr_t *cbp;
 450                 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
 451
 452                 err = arc_read(NULL, dp->dp_spa, bp, pbuf,
 453                     arc_getbuf_func, &buf,
 454                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
 455                 if (err) {
 456                         mutex_enter(&dp->dp_spa->spa_scrub_lock);
 457                         dp->dp_spa->spa_scrub_errors++;
 458                         mutex_exit(&dp->dp_spa->spa_scrub_lock);
 459                         return;
 460                 }
 461                 cbp = buf->b_data;
 462
 463                 for (i = 0; i < epb; i++, cbp++) {
 464                         zbookmark_t czb;
 465
 466                         SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
 467                             zb->zb_level - 1,
 468                             zb->zb_blkid * epb + i);
 469                         scrub_visitbp(dp, dnp, buf, cbp, &czb);
 470                 }
 471         } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
 472                 uint32_t flags = ARC_WAIT;
 473                 dnode_phys_t *child_dnp;
 474                 int i, j;
 475                 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
 476
 477                 err = arc_read(NULL, dp->dp_spa, bp, pbuf,
 478                     arc_getbuf_func, &buf,
 479                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
 480                 if (err) {
 481                         mutex_enter(&dp->dp_spa->spa_scrub_lock);
 482                         dp->dp_spa->spa_scrub_errors++;
 483                         mutex_exit(&dp->dp_spa->spa_scrub_lock);
 484                         return;
 485                 }
 486                 child_dnp = buf->b_data;
 487
 488                 for (i = 0; i < epb; i++, child_dnp++) {
 489                         for (j = 0; j < child_dnp->dn_nblkptr; j++) {
 490                                 zbookmark_t czb;
 491
 492                                 SET_BOOKMARK(&czb, zb->zb_objset,
 493                                     zb->zb_blkid * epb + i,
 494                                     child_dnp->dn_nlevels - 1, j);
 495                                 scrub_visitbp(dp, child_dnp, buf,
 496                                     &child_dnp->dn_blkptr[j], &czb);
 497                         }
 498                 }
 499         } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
 500                 uint32_t flags = ARC_WAIT;
 501                 objset_phys_t *osp;
 502                 int j;
 503
 504                 err = arc_read_nolock(NULL, dp->dp_spa, bp,
 505                     arc_getbuf_func, &buf,
 506                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
 507                 if (err) {
 508                         mutex_enter(&dp->dp_spa->spa_scrub_lock);
 509                         dp->dp_spa->spa_scrub_errors++;
 510                         mutex_exit(&dp->dp_spa->spa_scrub_lock);
 511                         return;
 512                 }
 513
 514                 osp = buf->b_data;
 515
 516                 traverse_zil(dp, &osp->os_zil_header);
 517
 518                 for (j = 0; j < osp->os_meta_dnode.dn_nblkptr; j++) {
 519                         zbookmark_t czb;
 520
 521                         SET_BOOKMARK(&czb, zb->zb_objset, 0,
 522                             osp->os_meta_dnode.dn_nlevels - 1, j);
 523                         scrub_visitbp(dp, &osp->os_meta_dnode, buf,
 524                             &osp->os_meta_dnode.dn_blkptr[j], &czb);
 525                 }
 526         }
 527
 528         (void) scrub_funcs[dp->dp_scrub_func](dp, bp, zb);
 529         if (buf)
 530                 (void) arc_buf_remove_ref(buf, &buf);
 531 }
 532
 533 static void
 534 scrub_visit_rootbp(dsl_pool_t *dp, dsl_dataset_t *ds, blkptr_t *bp)
 535 {
 536         zbookmark_t zb;
 537
 538         SET_BOOKMARK(&zb, ds ? ds->ds_object : 0, 0, -1, 0);
 539         scrub_visitbp(dp, NULL, NULL, bp, &zb);
 540 }
 541
 542 void
 543 dsl_pool_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx)
 544 {
 545         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 546
 547         if (dp->dp_scrub_func == SCRUB_FUNC_NONE)
 548                 return;
 549
 550         if (dp->dp_scrub_bookmark.zb_objset == ds->ds_object) {
 551                 SET_BOOKMARK(&dp->dp_scrub_bookmark, -1, 0, 0, 0);
 552         } else if (zap_remove_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 553             ds->ds_object, tx) != 0) {
 554                 return;
 555         }
 556
 557         if (ds->ds_phys->ds_next_snap_obj != 0) {
 558                 VERIFY(zap_add_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 559                     ds->ds_phys->ds_next_snap_obj, tx) == 0);
 560         }
 561         ASSERT3U(ds->ds_phys->ds_num_children, <=, 1);
 562 }
 563
 564 void
 565 dsl_pool_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx)
 566 {
 567         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 568
 569         if (dp->dp_scrub_func == SCRUB_FUNC_NONE)
 570                 return;
 571
 572         ASSERT(ds->ds_phys->ds_prev_snap_obj != 0);
 573
 574         if (dp->dp_scrub_bookmark.zb_objset == ds->ds_object) {
 575                 dp->dp_scrub_bookmark.zb_objset =
 576                     ds->ds_phys->ds_prev_snap_obj;
 577         } else if (zap_remove_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 578             ds->ds_object, tx) == 0) {
 579                 VERIFY(zap_add_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 580                     ds->ds_phys->ds_prev_snap_obj, tx) == 0);
 581         }
 582 }
 583
 584 void
 585 dsl_pool_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx)
 586 {
 587         dsl_pool_t *dp = ds1->ds_dir->dd_pool;
 588
 589         if (dp->dp_scrub_func == SCRUB_FUNC_NONE)
 590                 return;
 591
 592         if (dp->dp_scrub_bookmark.zb_objset == ds1->ds_object) {
 593                 dp->dp_scrub_bookmark.zb_objset = ds2->ds_object;
 594         } else if (dp->dp_scrub_bookmark.zb_objset == ds2->ds_object) {
 595                 dp->dp_scrub_bookmark.zb_objset = ds1->ds_object;
 596         }
 597
 598         if (zap_remove_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 599             ds1->ds_object, tx) == 0) {
 600                 int err = zap_add_int(dp->dp_meta_objset,
 601                     dp->dp_scrub_queue_obj, ds2->ds_object, tx);
 602                 VERIFY(err == 0 || err == EEXIST);
 603                 if (err == EEXIST) {
 604                         /* Both were there to begin with */
 605                         VERIFY(0 == zap_add_int(dp->dp_meta_objset,
 606                             dp->dp_scrub_queue_obj, ds1->ds_object, tx));
 607                 }
 608         } else if (zap_remove_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 609             ds2->ds_object, tx) == 0) {
 610                 VERIFY(0 == zap_add_int(dp->dp_meta_objset,
 611                     dp->dp_scrub_queue_obj, ds1->ds_object, tx));
 612         }
 613 }
 614
 615 struct enqueue_clones_arg {
 616         dmu_tx_t *tx;
 617         uint64_t originobj;
 618 };
 619
 620 /* ARGSUSED */
 621 static int
 622 enqueue_clones_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
 623 {
 624         struct enqueue_clones_arg *eca = arg;
 625         dsl_dataset_t *ds;
 626         int err;
 627         dsl_pool_t *dp;
 628
 629         err = dsl_dataset_hold_obj(spa->spa_dsl_pool, dsobj, FTAG, &ds);
 630         if (err)
 631                 return (err);
 632         dp = ds->ds_dir->dd_pool;
 633
 634         if (ds->ds_dir->dd_phys->dd_origin_obj == eca->originobj) {
 635                 while (ds->ds_phys->ds_prev_snap_obj != eca->originobj) {
 636                         dsl_dataset_t *prev;
 637                         err = dsl_dataset_hold_obj(dp,
 638                             ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
 639
 640                         dsl_dataset_rele(ds, FTAG);
 641                         if (err)
 642                                 return (err);
 643                         ds = prev;
 644                 }
 645                 VERIFY(zap_add_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 646                     ds->ds_object, eca->tx) == 0);
 647         }
 648         dsl_dataset_rele(ds, FTAG);
 649         return (0);
 650 }
 651
 652 static void
 653 scrub_visitds(dsl_pool_t *dp, uint64_t dsobj, dmu_tx_t *tx)
 654 {
 655         dsl_dataset_t *ds;
 656         uint64_t min_txg_save;
 657
 658         VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
 659
 660         /*
 661          * Iterate over the bps in this ds.
 662          */
 663         min_txg_save = dp->dp_scrub_min_txg;
 664         dp->dp_scrub_min_txg =
 665             MAX(dp->dp_scrub_min_txg, ds->ds_phys->ds_prev_snap_txg);
 666         scrub_visit_rootbp(dp, ds, &ds->ds_phys->ds_bp);
 667         dp->dp_scrub_min_txg = min_txg_save;
 668
 669         if (dp->dp_scrub_pausing)
 670                 goto out;
 671
 672         /*
 673          * Add descendent datasets to work queue.
 674          */
 675         if (ds->ds_phys->ds_next_snap_obj != 0) {
 676                 VERIFY(zap_add_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 677                     ds->ds_phys->ds_next_snap_obj, tx) == 0);
 678         }
 679         if (ds->ds_phys->ds_num_children > 1) {
 680                 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) {
 681                         struct enqueue_clones_arg eca;
 682                         eca.tx = tx;
 683                         eca.originobj = ds->ds_object;
 684
 685                         (void) dmu_objset_find_spa(ds->ds_dir->dd_pool->dp_spa,
 686                             NULL, enqueue_clones_cb, &eca, DS_FIND_CHILDREN);
 687                 } else {
 688                         VERIFY(zap_join(dp->dp_meta_objset,
 689                             ds->ds_phys->ds_next_clones_obj,
 690                             dp->dp_scrub_queue_obj, tx) == 0);
 691                 }
 692         }
 693
 694 out:
 695         dsl_dataset_rele(ds, FTAG);
 696 }
 697
 698 /* ARGSUSED */
 699 static int
 700 enqueue_cb(spa_t *spa, uint64_t dsobj, const char *dsname, void *arg)
 701 {
 702         dmu_tx_t *tx = arg;
 703         dsl_dataset_t *ds;
 704         int err;
 705         dsl_pool_t *dp;
 706
 707         err = dsl_dataset_hold_obj(spa->spa_dsl_pool, dsobj, FTAG, &ds);
 708         if (err)
 709                 return (err);
 710
 711         dp = ds->ds_dir->dd_pool;
 712
 713         while (ds->ds_phys->ds_prev_snap_obj != 0) {
 714                 dsl_dataset_t *prev;
 715                 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
 716                     FTAG, &prev);
 717                 if (err) {
 718                         dsl_dataset_rele(ds, FTAG);
 719                         return (err);
 720                 }
 721
 722                 /*
 723                  * If this is a clone, we don't need to worry about it for now.
 724                  */
 725                 if (prev->ds_phys->ds_next_snap_obj != ds->ds_object) {
 726                         dsl_dataset_rele(ds, FTAG);
 727                         dsl_dataset_rele(prev, FTAG);
 728                         return (0);
 729                 }
 730                 dsl_dataset_rele(ds, FTAG);
 731                 ds = prev;
 732         }
 733
 734         VERIFY(zap_add_int(dp->dp_meta_objset, dp->dp_scrub_queue_obj,
 735             ds->ds_object, tx) == 0);
 736         dsl_dataset_rele(ds, FTAG);
 737         return (0);
 738 }
 739
 740 void
 741 dsl_pool_scrub_sync(dsl_pool_t *dp, dmu_tx_t *tx)
 742 {
 743         zap_cursor_t zc;
 744         zap_attribute_t za;
 745         boolean_t complete = B_TRUE;
 746
 747         if (dp->dp_scrub_func == SCRUB_FUNC_NONE)
 748                 return;
 749
 750         /* If the spa is not fully loaded, don't bother. */
 751         if (dp->dp_spa->spa_load_state != SPA_LOAD_NONE)
 752                 return;
 753
 754         if (dp->dp_scrub_restart) {
 755                 enum scrub_func func = dp->dp_scrub_func;
 756                 dp->dp_scrub_restart = B_FALSE;
 757                 dsl_pool_scrub_setup_sync(dp, &func, kcred, tx);
 758         }
 759
 760         if (dp->dp_spa->spa_root_vdev->vdev_stat.vs_scrub_type == 0) {
 761                 /*
 762                  * We must have resumed after rebooting; reset the vdev
 763                  * stats to know that we're doing a scrub (although it
 764                  * will think we're just starting now).
 765                  */
 766                 vdev_scrub_stat_update(dp->dp_spa->spa_root_vdev,
 767                     dp->dp_scrub_min_txg ? POOL_SCRUB_RESILVER :
 768                     POOL_SCRUB_EVERYTHING, B_FALSE);
 769         }
 770
 771         dp->dp_scrub_pausing = B_FALSE;
 772         dp->dp_scrub_start_time = lbolt64;
 773         dp->dp_scrub_isresilver = (dp->dp_scrub_min_txg != 0);
 774         dp->dp_spa->spa_scrub_active = B_TRUE;
 775
 776         if (dp->dp_scrub_bookmark.zb_objset == 0) {
 777                 /* First do the MOS & ORIGIN */
 778                 scrub_visit_rootbp(dp, NULL, &dp->dp_meta_rootbp);
 779                 if (dp->dp_scrub_pausing)
 780                         goto out;
 781
 782                 if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) {
 783                         VERIFY(0 == dmu_objset_find_spa(dp->dp_spa,
 784                             NULL, enqueue_cb, tx, DS_FIND_CHILDREN));
 785                 } else {
 786                         scrub_visitds(dp, dp->dp_origin_snap->ds_object, tx);
 787                 }
 788                 ASSERT(!dp->dp_scrub_pausing);
 789         } else if (dp->dp_scrub_bookmark.zb_objset != -1ULL) {
 790                 /*
 791                  * If we were paused, continue from here.  Note if the
 792                  * ds we were paused on was deleted, the zb_objset will
 793                  * be -1, so we will skip this and find a new objset
 794                  * below.
 795                  */
 796                 scrub_visitds(dp, dp->dp_scrub_bookmark.zb_objset, tx);
 797                 if (dp->dp_scrub_pausing)
 798                         goto out;
 799         }
 800
 801         /*
 802          * In case we were paused right at the end of the ds, zero the
 803          * bookmark so we don't think that we're still trying to resume.
 804          */
 805         bzero(&dp->dp_scrub_bookmark, sizeof (zbookmark_t));
 806
 807         /* keep pulling things out of the zap-object-as-queue */
 808         while (zap_cursor_init(&zc, dp->dp_meta_objset, dp->dp_scrub_queue_obj),
 809             zap_cursor_retrieve(&zc, &za) == 0) {
 810                 VERIFY(0 == zap_remove(dp->dp_meta_objset,
 811                     dp->dp_scrub_queue_obj, za.za_name, tx));
 812                 scrub_visitds(dp, za.za_first_integer, tx);
 813                 if (dp->dp_scrub_pausing)
 814                         break;
 815                 zap_cursor_fini(&zc);
 816         }
 817         zap_cursor_fini(&zc);
 818         if (dp->dp_scrub_pausing)
 819                 goto out;
 820
 821         /* done. */
 822
 823         dsl_pool_scrub_cancel_sync(dp, &complete, kcred, tx);
 824         return;
 825 out:
 826         VERIFY(0 == zap_update(dp->dp_meta_objset,
 827             DMU_POOL_DIRECTORY_OBJECT,
 828             DMU_POOL_SCRUB_BOOKMARK, sizeof (uint64_t), 4,
 829             &dp->dp_scrub_bookmark, tx));
 830         VERIFY(0 == zap_update(dp->dp_meta_objset,
 831             DMU_POOL_DIRECTORY_OBJECT,
 832             DMU_POOL_SCRUB_ERRORS, sizeof (uint64_t), 1,
 833             &dp->dp_spa->spa_scrub_errors, tx));
 834
 835         /* XXX this is scrub-clean specific */
 836         mutex_enter(&dp->dp_spa->spa_scrub_lock);
 837         while (dp->dp_spa->spa_scrub_inflight > 0) {
 838                 cv_wait(&dp->dp_spa->spa_scrub_io_cv,
 839                     &dp->dp_spa->spa_scrub_lock);
 840         }
 841         mutex_exit(&dp->dp_spa->spa_scrub_lock);
 842 }
 843
 844 void
 845 dsl_pool_scrub_restart(dsl_pool_t *dp)
 846 {
 847         mutex_enter(&dp->dp_scrub_cancel_lock);
 848         dp->dp_scrub_restart = B_TRUE;
 849         mutex_exit(&dp->dp_scrub_cancel_lock);
 850 }
 851
 852 /*
 853  * scrub consumers
 854  */
 855
 856 static void
 857 count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp)
 858 {
 859         int i;
 860
 861         /*
 862          * If we resume after a reboot, zab will be NULL; don't record
 863          * incomplete stats in that case.
 864          */
 865         if (zab == NULL)
 866                 return;
 867
 868         for (i = 0; i < 4; i++) {
 869                 int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS;
 870                 int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL;
 871                 zfs_blkstat_t *zb = &zab->zab_type[l][t];
 872                 int equal;
 873
 874                 zb->zb_count++;
 875                 zb->zb_asize += BP_GET_ASIZE(bp);
 876                 zb->zb_lsize += BP_GET_LSIZE(bp);
 877                 zb->zb_psize += BP_GET_PSIZE(bp);
 878                 zb->zb_gangs += BP_COUNT_GANG(bp);
 879
 880                 switch (BP_GET_NDVAS(bp)) {
 881                 case 2:
 882                         if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
 883                             DVA_GET_VDEV(&bp->blk_dva[1]))
 884                                 zb->zb_ditto_2_of_2_samevdev++;
 885                         break;
 886                 case 3:
 887                         equal = (DVA_GET_VDEV(&bp->blk_dva[0]) ==
 888                             DVA_GET_VDEV(&bp->blk_dva[1])) +
 889                             (DVA_GET_VDEV(&bp->blk_dva[0]) ==
 890                             DVA_GET_VDEV(&bp->blk_dva[2])) +
 891                             (DVA_GET_VDEV(&bp->blk_dva[1]) ==
 892                             DVA_GET_VDEV(&bp->blk_dva[2]));
 893                         if (equal == 1)
 894                                 zb->zb_ditto_2_of_3_samevdev++;
 895                         else if (equal == 3)
 896                                 zb->zb_ditto_3_of_3_samevdev++;
 897                         break;
 898                 }
 899         }
 900 }
 901
 902 static void
 903 dsl_pool_scrub_clean_done(zio_t *zio)
 904 {
 905         spa_t *spa = zio->io_spa;
 906
 907         zio_data_buf_free(zio->io_data, zio->io_size);
 908
 909         mutex_enter(&spa->spa_scrub_lock);
 910         spa->spa_scrub_inflight--;
 911         cv_broadcast(&spa->spa_scrub_io_cv);
 912
 913         if (zio->io_error && (zio->io_error != ECKSUM ||
 914             !(zio->io_flags & ZIO_FLAG_SPECULATIVE)))
 915                 spa->spa_scrub_errors++;
 916         mutex_exit(&spa->spa_scrub_lock);
 917 }
 918
 919 static int
 920 dsl_pool_scrub_clean_cb(dsl_pool_t *dp,
 921     const blkptr_t *bp, const zbookmark_t *zb)
 922 {
 923         size_t size = BP_GET_LSIZE(bp);
 924         int d;
 925         spa_t *spa = dp->dp_spa;
 926         boolean_t needs_io;
 927         int zio_flags = ZIO_FLAG_SCRUB_THREAD | ZIO_FLAG_CANFAIL;
 928         int zio_priority;
 929
 930         count_block(dp->dp_blkstats, bp);
 931
 932         if (dp->dp_scrub_isresilver == 0) {
 933                 /* It's a scrub */
 934                 zio_flags |= ZIO_FLAG_SCRUB;
 935                 zio_priority = ZIO_PRIORITY_SCRUB;
 936                 needs_io = B_TRUE;
 937         } else {
 938                 /* It's a resilver */
 939                 zio_flags |= ZIO_FLAG_RESILVER;
 940                 zio_priority = ZIO_PRIORITY_RESILVER;
 941                 needs_io = B_FALSE;
 942         }
 943
 944         /* If it's an intent log block, failure is expected. */
 945         if (zb->zb_level == -1 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)
 946                 zio_flags |= ZIO_FLAG_SPECULATIVE;
 947
 948         for (d = 0; d < BP_GET_NDVAS(bp); d++) {
 949                 vdev_t *vd = vdev_lookup_top(spa,
 950                     DVA_GET_VDEV(&bp->blk_dva[d]));
 951
 952                 /*
 953                  * Keep track of how much data we've examined so that
 954                  * zpool(1M) status can make useful progress reports.
 955                  */
 956                 mutex_enter(&vd->vdev_stat_lock);
 957                 vd->vdev_stat.vs_scrub_examined +=
 958                     DVA_GET_ASIZE(&bp->blk_dva[d]);
 959                 mutex_exit(&vd->vdev_stat_lock);
 960
 961                 /* if it's a resilver, this may not be in the target range */
 962                 if (!needs_io) {
 963                         if (DVA_GET_GANG(&bp->blk_dva[d])) {
 964                                 /*
 965                                  * Gang members may be spread across multiple
 966                                  * vdevs, so the best we can do is look at the
 967                                  * pool-wide DTL.
 968                                  * XXX -- it would be better to change our
 969                                  * allocation policy to ensure that this can't
 970                                  * happen.
 971                                  */
 972                                 vd = spa->spa_root_vdev;
 973                         }
 974                         needs_io = vdev_dtl_contains(&vd->vdev_dtl_map,
 975                             bp->blk_birth, 1);
 976                 }
 977         }
 978
 979         if (needs_io && !zfs_no_scrub_io) {
 980                 void *data = zio_data_buf_alloc(size);
 981
 982                 mutex_enter(&spa->spa_scrub_lock);
 983                 while (spa->spa_scrub_inflight >= spa->spa_scrub_maxinflight)
 984                         cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
 985                 spa->spa_scrub_inflight++;
 986                 mutex_exit(&spa->spa_scrub_lock);
 987
 988                 zio_nowait(zio_read(NULL, spa, bp, data, size,
 989                     dsl_pool_scrub_clean_done, NULL, zio_priority,
 990                     zio_flags, zb));
 991         }
 992
 993         /* do not relocate this block */
 994         return (0);
 995 }
 996
 997 int
 998 dsl_pool_scrub_clean(dsl_pool_t *dp)
 999 {
1000         /*
1001          * Purge all vdev caches.  We do this here rather than in sync
1002          * context because this requires a writer lock on the spa_config
1003          * lock, which we can't do from sync context.  The
1004          * spa_scrub_reopen flag indicates that vdev_open() should not
1005          * attempt to start another scrub.
1006          */
1007         spa_config_enter(dp->dp_spa, SCL_ALL, FTAG, RW_WRITER);
1008         dp->dp_spa->spa_scrub_reopen = B_TRUE;
1009         vdev_reopen(dp->dp_spa->spa_root_vdev);
1010         dp->dp_spa->spa_scrub_reopen = B_FALSE;
1011         spa_config_exit(dp->dp_spa, SCL_ALL, FTAG);
1012
1013         return (dsl_pool_scrub_setup(dp, SCRUB_FUNC_CLEAN));
1014 }