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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  24  * Copyright (c) 2013 by Delphix. All rights reserved.
  25  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  26  */
  27 
  28 #include <sys/dmu.h>
  29 #include <sys/dmu_impl.h>
  30 #include <sys/dmu_tx.h>
  31 #include <sys/dbuf.h>
  32 #include <sys/dnode.h>
  33 #include <sys/zfs_context.h>
  34 #include <sys/dmu_objset.h>
  35 #include <sys/dmu_traverse.h>
  36 #include <sys/dsl_dataset.h>
  37 #include <sys/dsl_dir.h>
  38 #include <sys/dsl_prop.h>
  39 #include <sys/dsl_pool.h>
  40 #include <sys/dsl_synctask.h>
  41 #include <sys/zfs_ioctl.h>
  42 #include <sys/zap.h>
  43 #include <sys/zio_checksum.h>
  44 #include <sys/zfs_znode.h>
  45 #include <zfs_fletcher.h>
  46 #include <sys/avl.h>
  47 #include <sys/ddt.h>
  48 #include <sys/zfs_onexit.h>
  49 #include <sys/dmu_send.h>
  50 #include <sys/dsl_destroy.h>
  51 
  52 /* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
  53 int zfs_send_corrupt_data = B_FALSE;
  54 
  55 static char *dmu_recv_tag = "dmu_recv_tag";
  56 static const char *recv_clone_name = "%recv";
  57 
  58 static int
  59 dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
  60 {
  61         dsl_dataset_t *ds = dsp->dsa_os->os_dsl_dataset;
  62         ssize_t resid; /* have to get resid to get detailed errno */
  63         ASSERT0(len % 8);
  64 
  65         fletcher_4_incremental_native(buf, len, &dsp->dsa_zc);
  66         dsp->dsa_err = vn_rdwr(UIO_WRITE, dsp->dsa_vp,
  67             (caddr_t)buf, len,
  68             0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
  69 
  70         mutex_enter(&ds->ds_sendstream_lock);
  71         *dsp->dsa_off += len;
  72         mutex_exit(&ds->ds_sendstream_lock);
  73 
  74         return (dsp->dsa_err);
  75 }
  76 
  77 static int
  78 dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
  79     uint64_t length)
  80 {
  81         struct drr_free *drrf = &(dsp->dsa_drr->drr_u.drr_free);
  82 
  83         /*
  84          * When we receive a free record, dbuf_free_range() assumes
  85          * that the receiving system doesn't have any dbufs in the range
  86          * being freed.  This is always true because there is a one-record
  87          * constraint: we only send one WRITE record for any given
  88          * object+offset.  We know that the one-record constraint is
  89          * true because we always send data in increasing order by
  90          * object,offset.
  91          *
  92          * If the increasing-order constraint ever changes, we should find
  93          * another way to assert that the one-record constraint is still
  94          * satisfied.
  95          */
  96         ASSERT(object > dsp->dsa_last_data_object ||
  97             (object == dsp->dsa_last_data_object &&
  98             offset > dsp->dsa_last_data_offset));
  99 
 100         /*
 101          * If we are doing a non-incremental send, then there can't
 102          * be any data in the dataset we're receiving into.  Therefore
 103          * a free record would simply be a no-op.  Save space by not
 104          * sending it to begin with.
 105          */
 106         if (!dsp->dsa_incremental)
 107                 return (0);
 108 
 109         if (length != -1ULL && offset + length < offset)
 110                 length = -1ULL;
 111 
 112         /*
 113          * If there is a pending op, but it's not PENDING_FREE, push it out,
 114          * since free block aggregation can only be done for blocks of the
 115          * same type (i.e., DRR_FREE records can only be aggregated with
 116          * other DRR_FREE records.  DRR_FREEOBJECTS records can only be
 117          * aggregated with other DRR_FREEOBJECTS records.
 118          */
 119         if (dsp->dsa_pending_op != PENDING_NONE &&
 120             dsp->dsa_pending_op != PENDING_FREE) {
 121                 if (dump_bytes(dsp, dsp->dsa_drr,
 122                     sizeof (dmu_replay_record_t)) != 0)
 123                         return (SET_ERROR(EINTR));
 124                 dsp->dsa_pending_op = PENDING_NONE;
 125         }
 126 
 127         if (dsp->dsa_pending_op == PENDING_FREE) {
 128                 /*
 129                  * There should never be a PENDING_FREE if length is -1
 130                  * (because dump_dnode is the only place where this
 131                  * function is called with a -1, and only after flushing
 132                  * any pending record).
 133                  */
 134                 ASSERT(length != -1ULL);
 135                 /*
 136                  * Check to see whether this free block can be aggregated
 137                  * with pending one.
 138                  */
 139                 if (drrf->drr_object == object && drrf->drr_offset +
 140                     drrf->drr_length == offset) {
 141                         drrf->drr_length += length;
 142                         return (0);
 143                 } else {
 144                         /* not a continuation.  Push out pending record */
 145                         if (dump_bytes(dsp, dsp->dsa_drr,
 146                             sizeof (dmu_replay_record_t)) != 0)
 147                                 return (SET_ERROR(EINTR));
 148                         dsp->dsa_pending_op = PENDING_NONE;
 149                 }
 150         }
 151         /* create a FREE record and make it pending */
 152         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 153         dsp->dsa_drr->drr_type = DRR_FREE;
 154         drrf->drr_object = object;
 155         drrf->drr_offset = offset;
 156         drrf->drr_length = length;
 157         drrf->drr_toguid = dsp->dsa_toguid;
 158         if (length == -1ULL) {
 159                 if (dump_bytes(dsp, dsp->dsa_drr,
 160                     sizeof (dmu_replay_record_t)) != 0)
 161                         return (SET_ERROR(EINTR));
 162         } else {
 163                 dsp->dsa_pending_op = PENDING_FREE;
 164         }
 165 
 166         return (0);
 167 }
 168 
 169 static int
 170 dump_data(dmu_sendarg_t *dsp, dmu_object_type_t type,
 171     uint64_t object, uint64_t offset, int blksz, const blkptr_t *bp, void *data)
 172 {
 173         struct drr_write *drrw = &(dsp->dsa_drr->drr_u.drr_write);
 174 
 175         /*
 176          * We send data in increasing object, offset order.
 177          * See comment in dump_free() for details.
 178          */
 179         ASSERT(object > dsp->dsa_last_data_object ||
 180             (object == dsp->dsa_last_data_object &&
 181             offset > dsp->dsa_last_data_offset));
 182         dsp->dsa_last_data_object = object;
 183         dsp->dsa_last_data_offset = offset + blksz - 1;
 184 
 185         /*
 186          * If there is any kind of pending aggregation (currently either
 187          * a grouping of free objects or free blocks), push it out to
 188          * the stream, since aggregation can't be done across operations
 189          * of different types.
 190          */
 191         if (dsp->dsa_pending_op != PENDING_NONE) {
 192                 if (dump_bytes(dsp, dsp->dsa_drr,
 193                     sizeof (dmu_replay_record_t)) != 0)
 194                         return (SET_ERROR(EINTR));
 195                 dsp->dsa_pending_op = PENDING_NONE;
 196         }
 197         /* write a DATA record */
 198         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 199         dsp->dsa_drr->drr_type = DRR_WRITE;
 200         drrw->drr_object = object;
 201         drrw->drr_type = type;
 202         drrw->drr_offset = offset;
 203         drrw->drr_length = blksz;
 204         drrw->drr_toguid = dsp->dsa_toguid;
 205         drrw->drr_checksumtype = BP_GET_CHECKSUM(bp);
 206         if (zio_checksum_table[drrw->drr_checksumtype].ci_dedup)
 207                 drrw->drr_checksumflags |= DRR_CHECKSUM_DEDUP;
 208         DDK_SET_LSIZE(&drrw->drr_key, BP_GET_LSIZE(bp));
 209         DDK_SET_PSIZE(&drrw->drr_key, BP_GET_PSIZE(bp));
 210         DDK_SET_COMPRESS(&drrw->drr_key, BP_GET_COMPRESS(bp));
 211         drrw->drr_key.ddk_cksum = bp->blk_cksum;
 212 
 213         if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
 214                 return (SET_ERROR(EINTR));
 215         if (dump_bytes(dsp, data, blksz) != 0)
 216                 return (SET_ERROR(EINTR));
 217         return (0);
 218 }
 219 
 220 static int
 221 dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
 222 {
 223         struct drr_spill *drrs = &(dsp->dsa_drr->drr_u.drr_spill);
 224 
 225         if (dsp->dsa_pending_op != PENDING_NONE) {
 226                 if (dump_bytes(dsp, dsp->dsa_drr,
 227                     sizeof (dmu_replay_record_t)) != 0)
 228                         return (SET_ERROR(EINTR));
 229                 dsp->dsa_pending_op = PENDING_NONE;
 230         }
 231 
 232         /* write a SPILL record */
 233         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 234         dsp->dsa_drr->drr_type = DRR_SPILL;
 235         drrs->drr_object = object;
 236         drrs->drr_length = blksz;
 237         drrs->drr_toguid = dsp->dsa_toguid;
 238 
 239         if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)))
 240                 return (SET_ERROR(EINTR));
 241         if (dump_bytes(dsp, data, blksz))
 242                 return (SET_ERROR(EINTR));
 243         return (0);
 244 }
 245 
 246 static int
 247 dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
 248 {
 249         struct drr_freeobjects *drrfo = &(dsp->dsa_drr->drr_u.drr_freeobjects);
 250 
 251         /* See comment in dump_free(). */
 252         if (!dsp->dsa_incremental)
 253                 return (0);
 254 
 255         /*
 256          * If there is a pending op, but it's not PENDING_FREEOBJECTS,
 257          * push it out, since free block aggregation can only be done for
 258          * blocks of the same type (i.e., DRR_FREE records can only be
 259          * aggregated with other DRR_FREE records.  DRR_FREEOBJECTS records
 260          * can only be aggregated with other DRR_FREEOBJECTS records.
 261          */
 262         if (dsp->dsa_pending_op != PENDING_NONE &&
 263             dsp->dsa_pending_op != PENDING_FREEOBJECTS) {
 264                 if (dump_bytes(dsp, dsp->dsa_drr,
 265                     sizeof (dmu_replay_record_t)) != 0)
 266                         return (SET_ERROR(EINTR));
 267                 dsp->dsa_pending_op = PENDING_NONE;
 268         }
 269         if (dsp->dsa_pending_op == PENDING_FREEOBJECTS) {
 270                 /*
 271                  * See whether this free object array can be aggregated
 272                  * with pending one
 273                  */
 274                 if (drrfo->drr_firstobj + drrfo->drr_numobjs == firstobj) {
 275                         drrfo->drr_numobjs += numobjs;
 276                         return (0);
 277                 } else {
 278                         /* can't be aggregated.  Push out pending record */
 279                         if (dump_bytes(dsp, dsp->dsa_drr,
 280                             sizeof (dmu_replay_record_t)) != 0)
 281                                 return (SET_ERROR(EINTR));
 282                         dsp->dsa_pending_op = PENDING_NONE;
 283                 }
 284         }
 285 
 286         /* write a FREEOBJECTS record */
 287         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 288         dsp->dsa_drr->drr_type = DRR_FREEOBJECTS;
 289         drrfo->drr_firstobj = firstobj;
 290         drrfo->drr_numobjs = numobjs;
 291         drrfo->drr_toguid = dsp->dsa_toguid;
 292 
 293         dsp->dsa_pending_op = PENDING_FREEOBJECTS;
 294 
 295         return (0);
 296 }
 297 
 298 static int
 299 dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
 300 {
 301         struct drr_object *drro = &(dsp->dsa_drr->drr_u.drr_object);
 302 
 303         if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
 304                 return (dump_freeobjects(dsp, object, 1));
 305 
 306         if (dsp->dsa_pending_op != PENDING_NONE) {
 307                 if (dump_bytes(dsp, dsp->dsa_drr,
 308                     sizeof (dmu_replay_record_t)) != 0)
 309                         return (SET_ERROR(EINTR));
 310                 dsp->dsa_pending_op = PENDING_NONE;
 311         }
 312 
 313         /* write an OBJECT record */
 314         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 315         dsp->dsa_drr->drr_type = DRR_OBJECT;
 316         drro->drr_object = object;
 317         drro->drr_type = dnp->dn_type;
 318         drro->drr_bonustype = dnp->dn_bonustype;
 319         drro->drr_blksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 320         drro->drr_bonuslen = dnp->dn_bonuslen;
 321         drro->drr_checksumtype = dnp->dn_checksum;
 322         drro->drr_compress = dnp->dn_compress;
 323         drro->drr_toguid = dsp->dsa_toguid;
 324 
 325         if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
 326                 return (SET_ERROR(EINTR));
 327 
 328         if (dump_bytes(dsp, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0)
 329                 return (SET_ERROR(EINTR));
 330 
 331         /* Free anything past the end of the file. */
 332         if (dump_free(dsp, object, (dnp->dn_maxblkid + 1) *
 333             (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL) != 0)
 334                 return (SET_ERROR(EINTR));
 335         if (dsp->dsa_err != 0)
 336                 return (SET_ERROR(EINTR));
 337         return (0);
 338 }
 339 
 340 #define BP_SPAN(dnp, level) \
 341         (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
 342         (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
 343 
 344 /* ARGSUSED */
 345 static int
 346 backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 347     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
 348 {
 349         dmu_sendarg_t *dsp = arg;
 350         dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
 351         int err = 0;
 352 
 353         if (issig(JUSTLOOKING) && issig(FORREAL))
 354                 return (SET_ERROR(EINTR));
 355 
 356         if (zb->zb_object != DMU_META_DNODE_OBJECT &&
 357             DMU_OBJECT_IS_SPECIAL(zb->zb_object)) {
 358                 return (0);
 359         } else if (bp == NULL && zb->zb_object == DMU_META_DNODE_OBJECT) {
 360                 uint64_t span = BP_SPAN(dnp, zb->zb_level);
 361                 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
 362                 err = dump_freeobjects(dsp, dnobj, span >> DNODE_SHIFT);
 363         } else if (bp == NULL) {
 364                 uint64_t span = BP_SPAN(dnp, zb->zb_level);
 365                 err = dump_free(dsp, zb->zb_object, zb->zb_blkid * span, span);
 366         } else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
 367                 return (0);
 368         } else if (type == DMU_OT_DNODE) {
 369                 dnode_phys_t *blk;
 370                 int i;
 371                 int blksz = BP_GET_LSIZE(bp);
 372                 uint32_t aflags = ARC_WAIT;
 373                 arc_buf_t *abuf;
 374 
 375                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 376                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
 377                     &aflags, zb) != 0)
 378                         return (SET_ERROR(EIO));
 379 
 380                 blk = abuf->b_data;
 381                 for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
 382                         uint64_t dnobj = (zb->zb_blkid <<
 383                             (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
 384                         err = dump_dnode(dsp, dnobj, blk+i);
 385                         if (err != 0)
 386                                 break;
 387                 }
 388                 (void) arc_buf_remove_ref(abuf, &abuf);
 389         } else if (type == DMU_OT_SA) {
 390                 uint32_t aflags = ARC_WAIT;
 391                 arc_buf_t *abuf;
 392                 int blksz = BP_GET_LSIZE(bp);
 393 
 394                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 395                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
 396                     &aflags, zb) != 0)
 397                         return (SET_ERROR(EIO));
 398 
 399                 err = dump_spill(dsp, zb->zb_object, blksz, abuf->b_data);
 400                 (void) arc_buf_remove_ref(abuf, &abuf);
 401         } else { /* it's a level-0 block of a regular object */
 402                 uint32_t aflags = ARC_WAIT;
 403                 arc_buf_t *abuf;
 404                 int blksz = BP_GET_LSIZE(bp);
 405 
 406                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 407                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
 408                     &aflags, zb) != 0) {
 409                         if (zfs_send_corrupt_data) {
 410                                 /* Send a block filled with 0x"zfs badd bloc" */
 411                                 abuf = arc_buf_alloc(spa, blksz, &abuf,
 412                                     ARC_BUFC_DATA);
 413                                 uint64_t *ptr;
 414                                 for (ptr = abuf->b_data;
 415                                     (char *)ptr < (char *)abuf->b_data + blksz;
 416                                     ptr++)
 417                                         *ptr = 0x2f5baddb10c;
 418                         } else {
 419                                 return (SET_ERROR(EIO));
 420                         }
 421                 }
 422 
 423                 err = dump_data(dsp, type, zb->zb_object, zb->zb_blkid * blksz,
 424                     blksz, bp, abuf->b_data);
 425                 (void) arc_buf_remove_ref(abuf, &abuf);
 426         }
 427 
 428         ASSERT(err == 0 || err == EINTR);
 429         return (err);
 430 }
 431 
 432 /*
 433  * Releases dp, ds, and fromds, using the specified tag.
 434  */
 435 static int
 436 dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
 437     dsl_dataset_t *fromds, int outfd, vnode_t *vp, offset_t *off)
 438 {
 439         objset_t *os;
 440         dmu_replay_record_t *drr;
 441         dmu_sendarg_t *dsp;
 442         int err;
 443         uint64_t fromtxg = 0;
 444 
 445         if (fromds != NULL && !dsl_dataset_is_before(ds, fromds)) {
 446                 dsl_dataset_rele(fromds, tag);
 447                 dsl_dataset_rele(ds, tag);
 448                 dsl_pool_rele(dp, tag);
 449                 return (SET_ERROR(EXDEV));
 450         }
 451 
 452         err = dmu_objset_from_ds(ds, &os);
 453         if (err != 0) {
 454                 if (fromds != NULL)
 455                         dsl_dataset_rele(fromds, tag);
 456                 dsl_dataset_rele(ds, tag);
 457                 dsl_pool_rele(dp, tag);
 458                 return (err);
 459         }
 460 
 461         drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
 462         drr->drr_type = DRR_BEGIN;
 463         drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
 464         DMU_SET_STREAM_HDRTYPE(drr->drr_u.drr_begin.drr_versioninfo,
 465             DMU_SUBSTREAM);
 466 
 467 #ifdef _KERNEL
 468         if (dmu_objset_type(os) == DMU_OST_ZFS) {
 469                 uint64_t version;
 470                 if (zfs_get_zplprop(os, ZFS_PROP_VERSION, &version) != 0) {
 471                         kmem_free(drr, sizeof (dmu_replay_record_t));
 472                         if (fromds != NULL)
 473                                 dsl_dataset_rele(fromds, tag);
 474                         dsl_dataset_rele(ds, tag);
 475                         dsl_pool_rele(dp, tag);
 476                         return (SET_ERROR(EINVAL));
 477                 }
 478                 if (version >= ZPL_VERSION_SA) {
 479                         DMU_SET_FEATUREFLAGS(
 480                             drr->drr_u.drr_begin.drr_versioninfo,
 481                             DMU_BACKUP_FEATURE_SA_SPILL);
 482                 }
 483         }
 484 #endif
 485 
 486         drr->drr_u.drr_begin.drr_creation_time =
 487             ds->ds_phys->ds_creation_time;
 488         drr->drr_u.drr_begin.drr_type = dmu_objset_type(os);
 489         if (fromds != NULL && ds->ds_dir != fromds->ds_dir)
 490                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
 491         drr->drr_u.drr_begin.drr_toguid = ds->ds_phys->ds_guid;
 492         if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
 493                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CI_DATA;
 494 
 495         if (fromds != NULL)
 496                 drr->drr_u.drr_begin.drr_fromguid = fromds->ds_phys->ds_guid;
 497         dsl_dataset_name(ds, drr->drr_u.drr_begin.drr_toname);
 498 
 499         if (fromds != NULL) {
 500                 fromtxg = fromds->ds_phys->ds_creation_txg;
 501                 dsl_dataset_rele(fromds, tag);
 502                 fromds = NULL;
 503         }
 504 
 505         dsp = kmem_zalloc(sizeof (dmu_sendarg_t), KM_SLEEP);
 506 
 507         dsp->dsa_drr = drr;
 508         dsp->dsa_vp = vp;
 509         dsp->dsa_outfd = outfd;
 510         dsp->dsa_proc = curproc;
 511         dsp->dsa_os = os;
 512         dsp->dsa_off = off;
 513         dsp->dsa_toguid = ds->ds_phys->ds_guid;
 514         ZIO_SET_CHECKSUM(&dsp->dsa_zc, 0, 0, 0, 0);
 515         dsp->dsa_pending_op = PENDING_NONE;
 516         dsp->dsa_incremental = (fromtxg != 0);
 517 
 518         mutex_enter(&ds->ds_sendstream_lock);
 519         list_insert_head(&ds->ds_sendstreams, dsp);
 520         mutex_exit(&ds->ds_sendstream_lock);
 521 
 522         dsl_dataset_long_hold(ds, FTAG);
 523         dsl_pool_rele(dp, tag);
 524 
 525         if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
 526                 err = dsp->dsa_err;
 527                 goto out;
 528         }
 529 
 530         err = traverse_dataset(ds, fromtxg, TRAVERSE_PRE | TRAVERSE_PREFETCH,
 531             backup_cb, dsp);
 532 
 533         if (dsp->dsa_pending_op != PENDING_NONE)
 534                 if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0)
 535                         err = SET_ERROR(EINTR);
 536 
 537         if (err != 0) {
 538                 if (err == EINTR && dsp->dsa_err != 0)
 539                         err = dsp->dsa_err;
 540                 goto out;
 541         }
 542 
 543         bzero(drr, sizeof (dmu_replay_record_t));
 544         drr->drr_type = DRR_END;
 545         drr->drr_u.drr_end.drr_checksum = dsp->dsa_zc;
 546         drr->drr_u.drr_end.drr_toguid = dsp->dsa_toguid;
 547 
 548         if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
 549                 err = dsp->dsa_err;
 550                 goto out;
 551         }
 552 
 553 out:
 554         mutex_enter(&ds->ds_sendstream_lock);
 555         list_remove(&ds->ds_sendstreams, dsp);
 556         mutex_exit(&ds->ds_sendstream_lock);
 557 
 558         kmem_free(drr, sizeof (dmu_replay_record_t));
 559         kmem_free(dsp, sizeof (dmu_sendarg_t));
 560 
 561         dsl_dataset_long_rele(ds, FTAG);
 562         dsl_dataset_rele(ds, tag);
 563 
 564         return (err);
 565 }
 566 
 567 int
 568 dmu_send_obj(const char *pool, uint64_t tosnap, uint64_t fromsnap,
 569     int outfd, vnode_t *vp, offset_t *off)
 570 {
 571         dsl_pool_t *dp;
 572         dsl_dataset_t *ds;
 573         dsl_dataset_t *fromds = NULL;
 574         int err;
 575 
 576         err = dsl_pool_hold(pool, FTAG, &dp);
 577         if (err != 0)
 578                 return (err);
 579 
 580         err = dsl_dataset_hold_obj(dp, tosnap, FTAG, &ds);
 581         if (err != 0) {
 582                 dsl_pool_rele(dp, FTAG);
 583                 return (err);
 584         }
 585 
 586         if (fromsnap != 0) {
 587                 err = dsl_dataset_hold_obj(dp, fromsnap, FTAG, &fromds);
 588                 if (err != 0) {
 589                         dsl_dataset_rele(ds, FTAG);
 590                         dsl_pool_rele(dp, FTAG);
 591                         return (err);
 592                 }
 593         }
 594 
 595         return (dmu_send_impl(FTAG, dp, ds, fromds, outfd, vp, off));
 596 }
 597 
 598 int
 599 dmu_send(const char *tosnap, const char *fromsnap,
 600     int outfd, vnode_t *vp, offset_t *off)
 601 {
 602         dsl_pool_t *dp;
 603         dsl_dataset_t *ds;
 604         dsl_dataset_t *fromds = NULL;
 605         int err;
 606 
 607         if (strchr(tosnap, '@') == NULL)
 608                 return (SET_ERROR(EINVAL));
 609         if (fromsnap != NULL && strchr(fromsnap, '@') == NULL)
 610                 return (SET_ERROR(EINVAL));
 611 
 612         err = dsl_pool_hold(tosnap, FTAG, &dp);
 613         if (err != 0)
 614                 return (err);
 615 
 616         err = dsl_dataset_hold(dp, tosnap, FTAG, &ds);
 617         if (err != 0) {
 618                 dsl_pool_rele(dp, FTAG);
 619                 return (err);
 620         }
 621 
 622         if (fromsnap != NULL) {
 623                 err = dsl_dataset_hold(dp, fromsnap, FTAG, &fromds);
 624                 if (err != 0) {
 625                         dsl_dataset_rele(ds, FTAG);
 626                         dsl_pool_rele(dp, FTAG);
 627                         return (err);
 628                 }
 629         }
 630         return (dmu_send_impl(FTAG, dp, ds, fromds, outfd, vp, off));
 631 }
 632 
 633 int
 634 dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds, uint64_t *sizep)
 635 {
 636         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 637         int err;
 638         uint64_t size;
 639 
 640         ASSERT(dsl_pool_config_held(dp));
 641 
 642         /* tosnap must be a snapshot */
 643         if (!dsl_dataset_is_snapshot(ds))
 644                 return (SET_ERROR(EINVAL));
 645 
 646         /*
 647          * fromsnap must be an earlier snapshot from the same fs as tosnap,
 648          * or the origin's fs.
 649          */
 650         if (fromds != NULL && !dsl_dataset_is_before(ds, fromds))
 651                 return (SET_ERROR(EXDEV));
 652 
 653         /* Get uncompressed size estimate of changed data. */
 654         if (fromds == NULL) {
 655                 size = ds->ds_phys->ds_uncompressed_bytes;
 656         } else {
 657                 uint64_t used, comp;
 658                 err = dsl_dataset_space_written(fromds, ds,
 659                     &used, &comp, &size);
 660                 if (err != 0)
 661                         return (err);
 662         }
 663 
 664         /*
 665          * Assume that space (both on-disk and in-stream) is dominated by
 666          * data.  We will adjust for indirect blocks and the copies property,
 667          * but ignore per-object space used (eg, dnodes and DRR_OBJECT records).
 668          */
 669 
 670         /*
 671          * Subtract out approximate space used by indirect blocks.
 672          * Assume most space is used by data blocks (non-indirect, non-dnode).
 673          * Assume all blocks are recordsize.  Assume ditto blocks and
 674          * internal fragmentation counter out compression.
 675          *
 676          * Therefore, space used by indirect blocks is sizeof(blkptr_t) per
 677          * block, which we observe in practice.
 678          */
 679         uint64_t recordsize;
 680         err = dsl_prop_get_int_ds(ds, "recordsize", &recordsize);
 681         if (err != 0)
 682                 return (err);
 683         size -= size / recordsize * sizeof (blkptr_t);
 684 
 685         /* Add in the space for the record associated with each block. */
 686         size += size / recordsize * sizeof (dmu_replay_record_t);
 687 
 688         *sizep = size;
 689 
 690         return (0);
 691 }
 692 
 693 typedef struct dmu_recv_begin_arg {
 694         const char *drba_origin;
 695         dmu_recv_cookie_t *drba_cookie;
 696         cred_t *drba_cred;
 697         uint64_t drba_snapobj;
 698 } dmu_recv_begin_arg_t;
 699 
 700 static int
 701 recv_begin_check_existing_impl(dmu_recv_begin_arg_t *drba, dsl_dataset_t *ds,
 702     uint64_t fromguid)
 703 {
 704         uint64_t val;
 705         int error;
 706         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 707 
 708         /* temporary clone name must not exist */
 709         error = zap_lookup(dp->dp_meta_objset,
 710             ds->ds_dir->dd_phys->dd_child_dir_zapobj, recv_clone_name,
 711             8, 1, &val);
 712         if (error != ENOENT)
 713                 return (error == 0 ? EBUSY : error);
 714 
 715         /* new snapshot name must not exist */
 716         error = zap_lookup(dp->dp_meta_objset,
 717             ds->ds_phys->ds_snapnames_zapobj, drba->drba_cookie->drc_tosnap,
 718             8, 1, &val);
 719         if (error != ENOENT)
 720                 return (error == 0 ? EEXIST : error);
 721 
 722         if (fromguid != 0) {
 723                 dsl_dataset_t *snap;
 724                 uint64_t obj = ds->ds_phys->ds_prev_snap_obj;
 725 
 726                 /* Find snapshot in this dir that matches fromguid. */
 727                 while (obj != 0) {
 728                         error = dsl_dataset_hold_obj(dp, obj, FTAG,
 729                             &snap);
 730                         if (error != 0)
 731                                 return (SET_ERROR(ENODEV));
 732                         if (snap->ds_dir != ds->ds_dir) {
 733                                 dsl_dataset_rele(snap, FTAG);
 734                                 return (SET_ERROR(ENODEV));
 735                         }
 736                         if (snap->ds_phys->ds_guid == fromguid)
 737                                 break;
 738                         obj = snap->ds_phys->ds_prev_snap_obj;
 739                         dsl_dataset_rele(snap, FTAG);
 740                 }
 741                 if (obj == 0)
 742                         return (SET_ERROR(ENODEV));
 743 
 744                 if (drba->drba_cookie->drc_force) {
 745                         drba->drba_snapobj = obj;
 746                 } else {
 747                         /*
 748                          * If we are not forcing, there must be no
 749                          * changes since fromsnap.
 750                          */
 751                         if (dsl_dataset_modified_since_snap(ds, snap)) {
 752                                 dsl_dataset_rele(snap, FTAG);
 753                                 return (SET_ERROR(ETXTBSY));
 754                         }
 755                         drba->drba_snapobj = ds->ds_prev->ds_object;
 756                 }
 757 
 758                 dsl_dataset_rele(snap, FTAG);
 759         } else {
 760                 /* if full, most recent snapshot must be $ORIGIN */
 761                 if (ds->ds_phys->ds_prev_snap_txg >= TXG_INITIAL)
 762                         return (SET_ERROR(ENODEV));
 763                 drba->drba_snapobj = ds->ds_phys->ds_prev_snap_obj;
 764         }
 765 
 766         return (0);
 767 
 768 }
 769 
 770 static int
 771 dmu_recv_begin_check(void *arg, dmu_tx_t *tx)
 772 {
 773         dmu_recv_begin_arg_t *drba = arg;
 774         dsl_pool_t *dp = dmu_tx_pool(tx);
 775         struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
 776         uint64_t fromguid = drrb->drr_fromguid;
 777         int flags = drrb->drr_flags;
 778         int error;
 779         dsl_dataset_t *ds;
 780         const char *tofs = drba->drba_cookie->drc_tofs;
 781 
 782         /* already checked */
 783         ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
 784 
 785         if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
 786             DMU_COMPOUNDSTREAM ||
 787             drrb->drr_type >= DMU_OST_NUMTYPES ||
 788             ((flags & DRR_FLAG_CLONE) && drba->drba_origin == NULL))
 789                 return (SET_ERROR(EINVAL));
 790 
 791         /* Verify pool version supports SA if SA_SPILL feature set */
 792         if ((DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
 793             DMU_BACKUP_FEATURE_SA_SPILL) &&
 794             spa_version(dp->dp_spa) < SPA_VERSION_SA) {
 795                 return (SET_ERROR(ENOTSUP));
 796         }
 797 
 798         error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
 799         if (error == 0) {
 800                 /* target fs already exists; recv into temp clone */
 801 
 802                 /* Can't recv a clone into an existing fs */
 803                 if (flags & DRR_FLAG_CLONE) {
 804                         dsl_dataset_rele(ds, FTAG);
 805                         return (SET_ERROR(EINVAL));
 806                 }
 807 
 808                 error = recv_begin_check_existing_impl(drba, ds, fromguid);
 809                 dsl_dataset_rele(ds, FTAG);
 810         } else if (error == ENOENT) {
 811                 /* target fs does not exist; must be a full backup or clone */
 812                 char buf[MAXNAMELEN];
 813 
 814                 /*
 815                  * If it's a non-clone incremental, we are missing the
 816                  * target fs, so fail the recv.
 817                  */
 818                 if (fromguid != 0 && !(flags & DRR_FLAG_CLONE))
 819                         return (SET_ERROR(ENOENT));
 820 
 821                 /* Open the parent of tofs */
 822                 ASSERT3U(strlen(tofs), <, MAXNAMELEN);
 823                 (void) strlcpy(buf, tofs, strrchr(tofs, '/') - tofs + 1);
 824                 error = dsl_dataset_hold(dp, buf, FTAG, &ds);
 825                 if (error != 0)
 826                         return (error);
 827 
 828                 if (drba->drba_origin != NULL) {
 829                         dsl_dataset_t *origin;
 830                         error = dsl_dataset_hold(dp, drba->drba_origin,
 831                             FTAG, &origin);
 832                         if (error != 0) {
 833                                 dsl_dataset_rele(ds, FTAG);
 834                                 return (error);
 835                         }
 836                         if (!dsl_dataset_is_snapshot(origin)) {
 837                                 dsl_dataset_rele(origin, FTAG);
 838                                 dsl_dataset_rele(ds, FTAG);
 839                                 return (SET_ERROR(EINVAL));
 840                         }
 841                         if (origin->ds_phys->ds_guid != fromguid) {
 842                                 dsl_dataset_rele(origin, FTAG);
 843                                 dsl_dataset_rele(ds, FTAG);
 844                                 return (SET_ERROR(ENODEV));
 845                         }
 846                         dsl_dataset_rele(origin, FTAG);
 847                 }
 848                 dsl_dataset_rele(ds, FTAG);
 849                 error = 0;
 850         }
 851         return (error);
 852 }
 853 
 854 static void
 855 dmu_recv_begin_sync(void *arg, dmu_tx_t *tx)
 856 {
 857         dmu_recv_begin_arg_t *drba = arg;
 858         dsl_pool_t *dp = dmu_tx_pool(tx);
 859         struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
 860         const char *tofs = drba->drba_cookie->drc_tofs;
 861         dsl_dataset_t *ds, *newds;
 862         uint64_t dsobj;
 863         int error;
 864         uint64_t crflags;
 865 
 866         crflags = (drrb->drr_flags & DRR_FLAG_CI_DATA) ?
 867             DS_FLAG_CI_DATASET : 0;
 868 
 869         error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
 870         if (error == 0) {
 871                 /* create temporary clone */
 872                 dsl_dataset_t *snap = NULL;
 873                 if (drba->drba_snapobj != 0) {
 874                         VERIFY0(dsl_dataset_hold_obj(dp,
 875                             drba->drba_snapobj, FTAG, &snap));
 876                 }
 877                 dsobj = dsl_dataset_create_sync(ds->ds_dir, recv_clone_name,
 878                     snap, crflags, drba->drba_cred, tx);
 879                 dsl_dataset_rele(snap, FTAG);
 880                 dsl_dataset_rele(ds, FTAG);
 881         } else {
 882                 dsl_dir_t *dd;
 883                 const char *tail;
 884                 dsl_dataset_t *origin = NULL;
 885 
 886                 VERIFY0(dsl_dir_hold(dp, tofs, FTAG, &dd, &tail));
 887 
 888                 if (drba->drba_origin != NULL) {
 889                         VERIFY0(dsl_dataset_hold(dp, drba->drba_origin,
 890                             FTAG, &origin));
 891                 }
 892 
 893                 /* Create new dataset. */
 894                 dsobj = dsl_dataset_create_sync(dd,
 895                     strrchr(tofs, '/') + 1,
 896                     origin, crflags, drba->drba_cred, tx);
 897                 if (origin != NULL)
 898                         dsl_dataset_rele(origin, FTAG);
 899                 dsl_dir_rele(dd, FTAG);
 900                 drba->drba_cookie->drc_newfs = B_TRUE;
 901         }
 902         VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &newds));
 903 
 904         dmu_buf_will_dirty(newds->ds_dbuf, tx);
 905         newds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
 906 
 907         /*
 908          * If we actually created a non-clone, we need to create the
 909          * objset in our new dataset.
 910          */
 911         if (BP_IS_HOLE(dsl_dataset_get_blkptr(newds))) {
 912                 (void) dmu_objset_create_impl(dp->dp_spa,
 913                     newds, dsl_dataset_get_blkptr(newds), drrb->drr_type, tx);
 914         }
 915 
 916         drba->drba_cookie->drc_ds = newds;
 917 
 918         spa_history_log_internal_ds(newds, "receive", tx, "");
 919 }
 920 
 921 /*
 922  * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
 923  * succeeds; otherwise we will leak the holds on the datasets.
 924  */
 925 int
 926 dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *drrb,
 927     boolean_t force, char *origin, dmu_recv_cookie_t *drc)
 928 {
 929         dmu_recv_begin_arg_t drba = { 0 };
 930         dmu_replay_record_t *drr;
 931 
 932         bzero(drc, sizeof (dmu_recv_cookie_t));
 933         drc->drc_drrb = drrb;
 934         drc->drc_tosnap = tosnap;
 935         drc->drc_tofs = tofs;
 936         drc->drc_force = force;
 937 
 938         if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
 939                 drc->drc_byteswap = B_TRUE;
 940         else if (drrb->drr_magic != DMU_BACKUP_MAGIC)
 941                 return (SET_ERROR(EINVAL));
 942 
 943         drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
 944         drr->drr_type = DRR_BEGIN;
 945         drr->drr_u.drr_begin = *drc->drc_drrb;
 946         if (drc->drc_byteswap) {
 947                 fletcher_4_incremental_byteswap(drr,
 948                     sizeof (dmu_replay_record_t), &drc->drc_cksum);
 949         } else {
 950                 fletcher_4_incremental_native(drr,
 951                     sizeof (dmu_replay_record_t), &drc->drc_cksum);
 952         }
 953         kmem_free(drr, sizeof (dmu_replay_record_t));
 954 
 955         if (drc->drc_byteswap) {
 956                 drrb->drr_magic = BSWAP_64(drrb->drr_magic);
 957                 drrb->drr_versioninfo = BSWAP_64(drrb->drr_versioninfo);
 958                 drrb->drr_creation_time = BSWAP_64(drrb->drr_creation_time);
 959                 drrb->drr_type = BSWAP_32(drrb->drr_type);
 960                 drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
 961                 drrb->drr_fromguid = BSWAP_64(drrb->drr_fromguid);
 962         }
 963 
 964         drba.drba_origin = origin;
 965         drba.drba_cookie = drc;
 966         drba.drba_cred = CRED();
 967 
 968         return (dsl_sync_task(tofs, dmu_recv_begin_check, dmu_recv_begin_sync,
 969             &drba, 5));
 970 }
 971 
 972 struct restorearg {
 973         int err;
 974         boolean_t byteswap;
 975         vnode_t *vp;
 976         char *buf;
 977         uint64_t voff;
 978         int bufsize; /* amount of memory allocated for buf */
 979         zio_cksum_t cksum;
 980         avl_tree_t *guid_to_ds_map;
 981 };
 982 
 983 typedef struct guid_map_entry {
 984         uint64_t        guid;
 985         dsl_dataset_t   *gme_ds;
 986         avl_node_t      avlnode;
 987 } guid_map_entry_t;
 988 
 989 static int
 990 guid_compare(const void *arg1, const void *arg2)
 991 {
 992         const guid_map_entry_t *gmep1 = arg1;
 993         const guid_map_entry_t *gmep2 = arg2;
 994 
 995         if (gmep1->guid < gmep2->guid)
 996                 return (-1);
 997         else if (gmep1->guid > gmep2->guid)
 998                 return (1);
 999         return (0);
1000 }
1001 
1002 static void
1003 free_guid_map_onexit(void *arg)
1004 {
1005         avl_tree_t *ca = arg;
1006         void *cookie = NULL;
1007         guid_map_entry_t *gmep;
1008 
1009         while ((gmep = avl_destroy_nodes(ca, &cookie)) != NULL) {
1010                 dsl_dataset_long_rele(gmep->gme_ds, gmep);
1011                 dsl_dataset_rele(gmep->gme_ds, gmep);
1012                 kmem_free(gmep, sizeof (guid_map_entry_t));
1013         }
1014         avl_destroy(ca);
1015         kmem_free(ca, sizeof (avl_tree_t));
1016 }
1017 
1018 static void *
1019 restore_read(struct restorearg *ra, int len)
1020 {
1021         void *rv;
1022         int done = 0;
1023 
1024         /* some things will require 8-byte alignment, so everything must */
1025         ASSERT0(len % 8);
1026 
1027         while (done < len) {
1028                 ssize_t resid;
1029 
1030                 ra->err = vn_rdwr(UIO_READ, ra->vp,
1031                     (caddr_t)ra->buf + done, len - done,
1032                     ra->voff, UIO_SYSSPACE, FAPPEND,
1033                     RLIM64_INFINITY, CRED(), &resid);
1034 
1035                 if (resid == len - done)
1036                         ra->err = SET_ERROR(EINVAL);
1037                 ra->voff += len - done - resid;
1038                 done = len - resid;
1039                 if (ra->err != 0)
1040                         return (NULL);
1041         }
1042 
1043         ASSERT3U(done, ==, len);
1044         rv = ra->buf;
1045         if (ra->byteswap)
1046                 fletcher_4_incremental_byteswap(rv, len, &ra->cksum);
1047         else
1048                 fletcher_4_incremental_native(rv, len, &ra->cksum);
1049         return (rv);
1050 }
1051 
1052 static void
1053 backup_byteswap(dmu_replay_record_t *drr)
1054 {
1055 #define DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
1056 #define DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
1057         drr->drr_type = BSWAP_32(drr->drr_type);
1058         drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
1059         switch (drr->drr_type) {
1060         case DRR_BEGIN:
1061                 DO64(drr_begin.drr_magic);
1062                 DO64(drr_begin.drr_versioninfo);
1063                 DO64(drr_begin.drr_creation_time);
1064                 DO32(drr_begin.drr_type);
1065                 DO32(drr_begin.drr_flags);
1066                 DO64(drr_begin.drr_toguid);
1067                 DO64(drr_begin.drr_fromguid);
1068                 break;
1069         case DRR_OBJECT:
1070                 DO64(drr_object.drr_object);
1071                 /* DO64(drr_object.drr_allocation_txg); */
1072                 DO32(drr_object.drr_type);
1073                 DO32(drr_object.drr_bonustype);
1074                 DO32(drr_object.drr_blksz);
1075                 DO32(drr_object.drr_bonuslen);
1076                 DO64(drr_object.drr_toguid);
1077                 break;
1078         case DRR_FREEOBJECTS:
1079                 DO64(drr_freeobjects.drr_firstobj);
1080                 DO64(drr_freeobjects.drr_numobjs);
1081                 DO64(drr_freeobjects.drr_toguid);
1082                 break;
1083         case DRR_WRITE:
1084                 DO64(drr_write.drr_object);
1085                 DO32(drr_write.drr_type);
1086                 DO64(drr_write.drr_offset);
1087                 DO64(drr_write.drr_length);
1088                 DO64(drr_write.drr_toguid);
1089                 DO64(drr_write.drr_key.ddk_cksum.zc_word[0]);
1090                 DO64(drr_write.drr_key.ddk_cksum.zc_word[1]);
1091                 DO64(drr_write.drr_key.ddk_cksum.zc_word[2]);
1092                 DO64(drr_write.drr_key.ddk_cksum.zc_word[3]);
1093                 DO64(drr_write.drr_key.ddk_prop);
1094                 break;
1095         case DRR_WRITE_BYREF:
1096                 DO64(drr_write_byref.drr_object);
1097                 DO64(drr_write_byref.drr_offset);
1098                 DO64(drr_write_byref.drr_length);
1099                 DO64(drr_write_byref.drr_toguid);
1100                 DO64(drr_write_byref.drr_refguid);
1101                 DO64(drr_write_byref.drr_refobject);
1102                 DO64(drr_write_byref.drr_refoffset);
1103                 DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[0]);
1104                 DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[1]);
1105                 DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[2]);
1106                 DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[3]);
1107                 DO64(drr_write_byref.drr_key.ddk_prop);
1108                 break;
1109         case DRR_FREE:
1110                 DO64(drr_free.drr_object);
1111                 DO64(drr_free.drr_offset);
1112                 DO64(drr_free.drr_length);
1113                 DO64(drr_free.drr_toguid);
1114                 break;
1115         case DRR_SPILL:
1116                 DO64(drr_spill.drr_object);
1117                 DO64(drr_spill.drr_length);
1118                 DO64(drr_spill.drr_toguid);
1119                 break;
1120         case DRR_END:
1121                 DO64(drr_end.drr_checksum.zc_word[0]);
1122                 DO64(drr_end.drr_checksum.zc_word[1]);
1123                 DO64(drr_end.drr_checksum.zc_word[2]);
1124                 DO64(drr_end.drr_checksum.zc_word[3]);
1125                 DO64(drr_end.drr_toguid);
1126                 break;
1127         }
1128 #undef DO64
1129 #undef DO32
1130 }
1131 
1132 static int
1133 restore_object(struct restorearg *ra, objset_t *os, struct drr_object *drro)
1134 {
1135         int err;
1136         dmu_tx_t *tx;
1137         void *data = NULL;
1138 
1139         if (drro->drr_type == DMU_OT_NONE ||
1140             !DMU_OT_IS_VALID(drro->drr_type) ||
1141             !DMU_OT_IS_VALID(drro->drr_bonustype) ||
1142             drro->drr_checksumtype >= ZIO_CHECKSUM_FUNCTIONS ||
1143             drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
1144             P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
1145             drro->drr_blksz < SPA_MINBLOCKSIZE ||
1146             drro->drr_blksz > SPA_MAXBLOCKSIZE ||
1147             drro->drr_bonuslen > DN_MAX_BONUSLEN) {
1148                 return (SET_ERROR(EINVAL));
1149         }
1150 
1151         err = dmu_object_info(os, drro->drr_object, NULL);
1152 
1153         if (err != 0 && err != ENOENT)
1154                 return (SET_ERROR(EINVAL));
1155 
1156         if (drro->drr_bonuslen) {
1157                 data = restore_read(ra, P2ROUNDUP(drro->drr_bonuslen, 8));
1158                 if (ra->err != 0)
1159                         return (ra->err);
1160         }
1161 
1162         if (err == ENOENT) {
1163                 /* currently free, want to be allocated */
1164                 tx = dmu_tx_create(os);
1165                 dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
1166                 err = dmu_tx_assign(tx, TXG_WAIT);
1167                 if (err != 0) {
1168                         dmu_tx_abort(tx);
1169                         return (err);
1170                 }
1171                 err = dmu_object_claim(os, drro->drr_object,
1172                     drro->drr_type, drro->drr_blksz,
1173                     drro->drr_bonustype, drro->drr_bonuslen, tx);
1174                 dmu_tx_commit(tx);
1175         } else {
1176                 /* currently allocated, want to be allocated */
1177                 err = dmu_object_reclaim(os, drro->drr_object,
1178                     drro->drr_type, drro->drr_blksz,
1179                     drro->drr_bonustype, drro->drr_bonuslen);
1180         }
1181         if (err != 0) {
1182                 return (SET_ERROR(EINVAL));
1183         }
1184 
1185         tx = dmu_tx_create(os);
1186         dmu_tx_hold_bonus(tx, drro->drr_object);
1187         err = dmu_tx_assign(tx, TXG_WAIT);
1188         if (err != 0) {
1189                 dmu_tx_abort(tx);
1190                 return (err);
1191         }
1192 
1193         dmu_object_set_checksum(os, drro->drr_object, drro->drr_checksumtype,
1194             tx);
1195         dmu_object_set_compress(os, drro->drr_object, drro->drr_compress, tx);
1196 
1197         if (data != NULL) {
1198                 dmu_buf_t *db;
1199 
1200                 VERIFY(0 == dmu_bonus_hold(os, drro->drr_object, FTAG, &db));
1201                 dmu_buf_will_dirty(db, tx);
1202 
1203                 ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
1204                 bcopy(data, db->db_data, drro->drr_bonuslen);
1205                 if (ra->byteswap) {
1206                         dmu_object_byteswap_t byteswap =
1207                             DMU_OT_BYTESWAP(drro->drr_bonustype);
1208                         dmu_ot_byteswap[byteswap].ob_func(db->db_data,
1209                             drro->drr_bonuslen);
1210                 }
1211                 dmu_buf_rele(db, FTAG);
1212         }
1213         dmu_tx_commit(tx);
1214         return (0);
1215 }
1216 
1217 /* ARGSUSED */
1218 static int
1219 restore_freeobjects(struct restorearg *ra, objset_t *os,
1220     struct drr_freeobjects *drrfo)
1221 {
1222         uint64_t obj;
1223 
1224         if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
1225                 return (SET_ERROR(EINVAL));
1226 
1227         for (obj = drrfo->drr_firstobj;
1228             obj < drrfo->drr_firstobj + drrfo->drr_numobjs;
1229             (void) dmu_object_next(os, &obj, FALSE, 0)) {
1230                 int err;
1231 
1232                 if (dmu_object_info(os, obj, NULL) != 0)
1233                         continue;
1234 
1235                 err = dmu_free_object(os, obj);
1236                 if (err != 0)
1237                         return (err);
1238         }
1239         return (0);
1240 }
1241 
1242 static int
1243 restore_write(struct restorearg *ra, objset_t *os,
1244     struct drr_write *drrw)
1245 {
1246         dmu_tx_t *tx;
1247         void *data;
1248         int err;
1249 
1250         if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
1251             !DMU_OT_IS_VALID(drrw->drr_type))
1252                 return (SET_ERROR(EINVAL));
1253 
1254         data = restore_read(ra, drrw->drr_length);
1255         if (data == NULL)
1256                 return (ra->err);
1257 
1258         if (dmu_object_info(os, drrw->drr_object, NULL) != 0)
1259                 return (SET_ERROR(EINVAL));
1260 
1261         tx = dmu_tx_create(os);
1262 
1263         dmu_tx_hold_write(tx, drrw->drr_object,
1264             drrw->drr_offset, drrw->drr_length);
1265         err = dmu_tx_assign(tx, TXG_WAIT);
1266         if (err != 0) {
1267                 dmu_tx_abort(tx);
1268                 return (err);
1269         }
1270         if (ra->byteswap) {
1271                 dmu_object_byteswap_t byteswap =
1272                     DMU_OT_BYTESWAP(drrw->drr_type);
1273                 dmu_ot_byteswap[byteswap].ob_func(data, drrw->drr_length);
1274         }
1275         dmu_write(os, drrw->drr_object,
1276             drrw->drr_offset, drrw->drr_length, data, tx);
1277         dmu_tx_commit(tx);
1278         return (0);
1279 }
1280 
1281 /*
1282  * Handle a DRR_WRITE_BYREF record.  This record is used in dedup'ed
1283  * streams to refer to a copy of the data that is already on the
1284  * system because it came in earlier in the stream.  This function
1285  * finds the earlier copy of the data, and uses that copy instead of
1286  * data from the stream to fulfill this write.
1287  */
1288 static int
1289 restore_write_byref(struct restorearg *ra, objset_t *os,
1290     struct drr_write_byref *drrwbr)
1291 {
1292         dmu_tx_t *tx;
1293         int err;
1294         guid_map_entry_t gmesrch;
1295         guid_map_entry_t *gmep;
1296         avl_index_t     where;
1297         objset_t *ref_os = NULL;
1298         dmu_buf_t *dbp;
1299 
1300         if (drrwbr->drr_offset + drrwbr->drr_length < drrwbr->drr_offset)
1301                 return (SET_ERROR(EINVAL));
1302 
1303         /*
1304          * If the GUID of the referenced dataset is different from the
1305          * GUID of the target dataset, find the referenced dataset.
1306          */
1307         if (drrwbr->drr_toguid != drrwbr->drr_refguid) {
1308                 gmesrch.guid = drrwbr->drr_refguid;
1309                 if ((gmep = avl_find(ra->guid_to_ds_map, &gmesrch,
1310                     &where)) == NULL) {
1311                         return (SET_ERROR(EINVAL));
1312                 }
1313                 if (dmu_objset_from_ds(gmep->gme_ds, &ref_os))
1314                         return (SET_ERROR(EINVAL));
1315         } else {
1316                 ref_os = os;
1317         }
1318 
1319         if (err = dmu_buf_hold(ref_os, drrwbr->drr_refobject,
1320             drrwbr->drr_refoffset, FTAG, &dbp, DMU_READ_PREFETCH))
1321                 return (err);
1322 
1323         tx = dmu_tx_create(os);
1324 
1325         dmu_tx_hold_write(tx, drrwbr->drr_object,
1326             drrwbr->drr_offset, drrwbr->drr_length);
1327         err = dmu_tx_assign(tx, TXG_WAIT);
1328         if (err != 0) {
1329                 dmu_tx_abort(tx);
1330                 return (err);
1331         }
1332         dmu_write(os, drrwbr->drr_object,
1333             drrwbr->drr_offset, drrwbr->drr_length, dbp->db_data, tx);
1334         dmu_buf_rele(dbp, FTAG);
1335         dmu_tx_commit(tx);
1336         return (0);
1337 }
1338 
1339 static int
1340 restore_spill(struct restorearg *ra, objset_t *os, struct drr_spill *drrs)
1341 {
1342         dmu_tx_t *tx;
1343         void *data;
1344         dmu_buf_t *db, *db_spill;
1345         int err;
1346 
1347         if (drrs->drr_length < SPA_MINBLOCKSIZE ||
1348             drrs->drr_length > SPA_MAXBLOCKSIZE)
1349                 return (SET_ERROR(EINVAL));
1350 
1351         data = restore_read(ra, drrs->drr_length);
1352         if (data == NULL)
1353                 return (ra->err);
1354 
1355         if (dmu_object_info(os, drrs->drr_object, NULL) != 0)
1356                 return (SET_ERROR(EINVAL));
1357 
1358         VERIFY(0 == dmu_bonus_hold(os, drrs->drr_object, FTAG, &db));
1359         if ((err = dmu_spill_hold_by_bonus(db, FTAG, &db_spill)) != 0) {
1360                 dmu_buf_rele(db, FTAG);
1361                 return (err);
1362         }
1363 
1364         tx = dmu_tx_create(os);
1365 
1366         dmu_tx_hold_spill(tx, db->db_object);
1367 
1368         err = dmu_tx_assign(tx, TXG_WAIT);
1369         if (err != 0) {
1370                 dmu_buf_rele(db, FTAG);
1371                 dmu_buf_rele(db_spill, FTAG);
1372                 dmu_tx_abort(tx);
1373                 return (err);
1374         }
1375         dmu_buf_will_dirty(db_spill, tx);
1376 
1377         if (db_spill->db_size < drrs->drr_length)
1378                 VERIFY(0 == dbuf_spill_set_blksz(db_spill,
1379                     drrs->drr_length, tx));
1380         bcopy(data, db_spill->db_data, drrs->drr_length);
1381 
1382         dmu_buf_rele(db, FTAG);
1383         dmu_buf_rele(db_spill, FTAG);
1384 
1385         dmu_tx_commit(tx);
1386         return (0);
1387 }
1388 
1389 /* ARGSUSED */
1390 static int
1391 restore_free(struct restorearg *ra, objset_t *os,
1392     struct drr_free *drrf)
1393 {
1394         int err;
1395 
1396         if (drrf->drr_length != -1ULL &&
1397             drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
1398                 return (SET_ERROR(EINVAL));
1399 
1400         if (dmu_object_info(os, drrf->drr_object, NULL) != 0)
1401                 return (SET_ERROR(EINVAL));
1402 
1403         err = dmu_free_long_range(os, drrf->drr_object,
1404             drrf->drr_offset, drrf->drr_length);
1405         return (err);
1406 }
1407 
1408 /* used to destroy the drc_ds on error */
1409 static void
1410 dmu_recv_cleanup_ds(dmu_recv_cookie_t *drc)
1411 {
1412         char name[MAXNAMELEN];
1413         dsl_dataset_name(drc->drc_ds, name);
1414         dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
1415         (void) dsl_destroy_head(name);
1416 }
1417 
1418 /*
1419  * NB: callers *must* call dmu_recv_end() if this succeeds.
1420  */
1421 int
1422 dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp,
1423     int cleanup_fd, uint64_t *action_handlep)
1424 {
1425         struct restorearg ra = { 0 };
1426         dmu_replay_record_t *drr;
1427         objset_t *os;
1428         zio_cksum_t pcksum;
1429         int featureflags;
1430 
1431         ra.byteswap = drc->drc_byteswap;
1432         ra.cksum = drc->drc_cksum;
1433         ra.vp = vp;
1434         ra.voff = *voffp;
1435         ra.bufsize = 1<<20;
1436         ra.buf = kmem_alloc(ra.bufsize, KM_SLEEP);
1437 
1438         /* these were verified in dmu_recv_begin */
1439         ASSERT3U(DMU_GET_STREAM_HDRTYPE(drc->drc_drrb->drr_versioninfo), ==,
1440             DMU_SUBSTREAM);
1441         ASSERT3U(drc->drc_drrb->drr_type, <, DMU_OST_NUMTYPES);
1442 
1443         /*
1444          * Open the objset we are modifying.
1445          */
1446         VERIFY0(dmu_objset_from_ds(drc->drc_ds, &os));
1447 
1448         ASSERT(drc->drc_ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT);
1449 
1450         featureflags = DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo);
1451 
1452         /* if this stream is dedup'ed, set up the avl tree for guid mapping */
1453         if (featureflags & DMU_BACKUP_FEATURE_DEDUP) {
1454                 minor_t minor;
1455 
1456                 if (cleanup_fd == -1) {
1457                         ra.err = SET_ERROR(EBADF);
1458                         goto out;
1459                 }
1460                 ra.err = zfs_onexit_fd_hold(cleanup_fd, &minor);
1461                 if (ra.err != 0) {
1462                         cleanup_fd = -1;
1463                         goto out;
1464                 }
1465 
1466                 if (*action_handlep == 0) {
1467                         ra.guid_to_ds_map =
1468                             kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
1469                         avl_create(ra.guid_to_ds_map, guid_compare,
1470                             sizeof (guid_map_entry_t),
1471                             offsetof(guid_map_entry_t, avlnode));
1472                         ra.err = zfs_onexit_add_cb(minor,
1473                             free_guid_map_onexit, ra.guid_to_ds_map,
1474                             action_handlep);
1475                         if (ra.err != 0)
1476                                 goto out;
1477                 } else {
1478                         ra.err = zfs_onexit_cb_data(minor, *action_handlep,
1479                             (void **)&ra.guid_to_ds_map);
1480                         if (ra.err != 0)
1481                                 goto out;
1482                 }
1483 
1484                 drc->drc_guid_to_ds_map = ra.guid_to_ds_map;
1485         }
1486 
1487         /*
1488          * Read records and process them.
1489          */
1490         pcksum = ra.cksum;
1491         while (ra.err == 0 &&
1492             NULL != (drr = restore_read(&ra, sizeof (*drr)))) {
1493                 if (issig(JUSTLOOKING) && issig(FORREAL)) {
1494                         ra.err = SET_ERROR(EINTR);
1495                         goto out;
1496                 }
1497 
1498                 if (ra.byteswap)
1499                         backup_byteswap(drr);
1500 
1501                 switch (drr->drr_type) {
1502                 case DRR_OBJECT:
1503                 {
1504                         /*
1505                          * We need to make a copy of the record header,
1506                          * because restore_{object,write} may need to
1507                          * restore_read(), which will invalidate drr.
1508                          */
1509                         struct drr_object drro = drr->drr_u.drr_object;
1510                         ra.err = restore_object(&ra, os, &drro);
1511                         break;
1512                 }
1513                 case DRR_FREEOBJECTS:
1514                 {
1515                         struct drr_freeobjects drrfo =
1516                             drr->drr_u.drr_freeobjects;
1517                         ra.err = restore_freeobjects(&ra, os, &drrfo);
1518                         break;
1519                 }
1520                 case DRR_WRITE:
1521                 {
1522                         struct drr_write drrw = drr->drr_u.drr_write;
1523                         ra.err = restore_write(&ra, os, &drrw);
1524                         break;
1525                 }
1526                 case DRR_WRITE_BYREF:
1527                 {
1528                         struct drr_write_byref drrwbr =
1529                             drr->drr_u.drr_write_byref;
1530                         ra.err = restore_write_byref(&ra, os, &drrwbr);
1531                         break;
1532                 }
1533                 case DRR_FREE:
1534                 {
1535                         struct drr_free drrf = drr->drr_u.drr_free;
1536                         ra.err = restore_free(&ra, os, &drrf);
1537                         break;
1538                 }
1539                 case DRR_END:
1540                 {
1541                         struct drr_end drre = drr->drr_u.drr_end;
1542                         /*
1543                          * We compare against the *previous* checksum
1544                          * value, because the stored checksum is of
1545                          * everything before the DRR_END record.
1546                          */
1547                         if (!ZIO_CHECKSUM_EQUAL(drre.drr_checksum, pcksum))
1548                                 ra.err = SET_ERROR(ECKSUM);
1549                         goto out;
1550                 }
1551                 case DRR_SPILL:
1552                 {
1553                         struct drr_spill drrs = drr->drr_u.drr_spill;
1554                         ra.err = restore_spill(&ra, os, &drrs);
1555                         break;
1556                 }
1557                 default:
1558                         ra.err = SET_ERROR(EINVAL);
1559                         goto out;
1560                 }
1561                 pcksum = ra.cksum;
1562         }
1563         ASSERT(ra.err != 0);
1564 
1565 out:
1566         if ((featureflags & DMU_BACKUP_FEATURE_DEDUP) && (cleanup_fd != -1))
1567                 zfs_onexit_fd_rele(cleanup_fd);
1568 
1569         if (ra.err != 0) {
1570                 /*
1571                  * destroy what we created, so we don't leave it in the
1572                  * inconsistent restoring state.
1573                  */
1574                 dmu_recv_cleanup_ds(drc);
1575         }
1576 
1577         kmem_free(ra.buf, ra.bufsize);
1578         *voffp = ra.voff;
1579         return (ra.err);
1580 }
1581 
1582 static int
1583 dmu_recv_end_check(void *arg, dmu_tx_t *tx)
1584 {
1585         dmu_recv_cookie_t *drc = arg;
1586         dsl_pool_t *dp = dmu_tx_pool(tx);
1587         int error;
1588 
1589         ASSERT3P(drc->drc_ds->ds_owner, ==, dmu_recv_tag);
1590 
1591         if (!drc->drc_newfs) {
1592                 dsl_dataset_t *origin_head;
1593 
1594                 error = dsl_dataset_hold(dp, drc->drc_tofs, FTAG, &origin_head);
1595                 if (error != 0)
1596                         return (error);
1597                 if (drc->drc_force) {
1598                         /*
1599                          * We will destroy any snapshots in tofs (i.e. before
1600                          * origin_head) that are after the origin (which is
1601                          * the snap before drc_ds, because drc_ds can not
1602                          * have any snaps of its own).
1603                          */
1604                         uint64_t obj = origin_head->ds_phys->ds_prev_snap_obj;
1605                         while (obj != drc->drc_ds->ds_phys->ds_prev_snap_obj) {
1606                                 dsl_dataset_t *snap;
1607                                 error = dsl_dataset_hold_obj(dp, obj, FTAG,
1608                                     &snap);
1609                                 if (error != 0)
1610                                         return (error);
1611                                 if (snap->ds_dir != origin_head->ds_dir)
1612                                         error = SET_ERROR(EINVAL);
1613                                 if (error == 0)  {
1614                                         error = dsl_destroy_snapshot_check_impl(
1615                                             snap, B_FALSE);
1616                                 }
1617                                 obj = snap->ds_phys->ds_prev_snap_obj;
1618                                 dsl_dataset_rele(snap, FTAG);
1619                                 if (error != 0)
1620                                         return (error);
1621                         }
1622                 }
1623                 error = dsl_dataset_clone_swap_check_impl(drc->drc_ds,
1624                     origin_head, drc->drc_force, drc->drc_owner, tx);
1625                 if (error != 0) {
1626                         dsl_dataset_rele(origin_head, FTAG);
1627                         return (error);
1628                 }
1629                 error = dsl_dataset_snapshot_check_impl(origin_head,
1630                     drc->drc_tosnap, tx, B_TRUE);
1631                 dsl_dataset_rele(origin_head, FTAG);
1632                 if (error != 0)
1633                         return (error);
1634 
1635                 error = dsl_destroy_head_check_impl(drc->drc_ds, 1);
1636         } else {
1637                 error = dsl_dataset_snapshot_check_impl(drc->drc_ds,
1638                     drc->drc_tosnap, tx, B_TRUE);
1639         }
1640         return (error);
1641 }
1642 
1643 static void
1644 dmu_recv_end_sync(void *arg, dmu_tx_t *tx)
1645 {
1646         dmu_recv_cookie_t *drc = arg;
1647         dsl_pool_t *dp = dmu_tx_pool(tx);
1648 
1649         spa_history_log_internal_ds(drc->drc_ds, "finish receiving",
1650             tx, "snap=%s", drc->drc_tosnap);
1651 
1652         if (!drc->drc_newfs) {
1653                 dsl_dataset_t *origin_head;
1654 
1655                 VERIFY0(dsl_dataset_hold(dp, drc->drc_tofs, FTAG,
1656                     &origin_head));
1657 
1658                 if (drc->drc_force) {
1659                         /*
1660                          * Destroy any snapshots of drc_tofs (origin_head)
1661                          * after the origin (the snap before drc_ds).
1662                          */
1663                         uint64_t obj = origin_head->ds_phys->ds_prev_snap_obj;
1664                         while (obj != drc->drc_ds->ds_phys->ds_prev_snap_obj) {
1665                                 dsl_dataset_t *snap;
1666                                 VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG,
1667                                     &snap));
1668                                 ASSERT3P(snap->ds_dir, ==, origin_head->ds_dir);
1669                                 obj = snap->ds_phys->ds_prev_snap_obj;
1670                                 dsl_destroy_snapshot_sync_impl(snap,
1671                                     B_FALSE, tx);
1672                                 dsl_dataset_rele(snap, FTAG);
1673                         }
1674                 }
1675                 VERIFY3P(drc->drc_ds->ds_prev, ==,
1676                     origin_head->ds_prev);
1677 
1678                 dsl_dataset_clone_swap_sync_impl(drc->drc_ds,
1679                     origin_head, tx);
1680                 dsl_dataset_snapshot_sync_impl(origin_head,
1681                     drc->drc_tosnap, tx);
1682 
1683                 /* set snapshot's creation time and guid */
1684                 dmu_buf_will_dirty(origin_head->ds_prev->ds_dbuf, tx);
1685                 origin_head->ds_prev->ds_phys->ds_creation_time =
1686                     drc->drc_drrb->drr_creation_time;
1687                 origin_head->ds_prev->ds_phys->ds_guid =
1688                     drc->drc_drrb->drr_toguid;
1689                 origin_head->ds_prev->ds_phys->ds_flags &=
1690                     ~DS_FLAG_INCONSISTENT;
1691 
1692                 dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
1693                 origin_head->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1694 
1695                 dsl_dataset_rele(origin_head, FTAG);
1696                 dsl_destroy_head_sync_impl(drc->drc_ds, tx);
1697 
1698                 if (drc->drc_owner != NULL)
1699                         VERIFY3P(origin_head->ds_owner, ==, drc->drc_owner);
1700         } else {
1701                 dsl_dataset_t *ds = drc->drc_ds;
1702 
1703                 dsl_dataset_snapshot_sync_impl(ds, drc->drc_tosnap, tx);
1704 
1705                 /* set snapshot's creation time and guid */
1706                 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1707                 ds->ds_prev->ds_phys->ds_creation_time =
1708                     drc->drc_drrb->drr_creation_time;
1709                 ds->ds_prev->ds_phys->ds_guid = drc->drc_drrb->drr_toguid;
1710                 ds->ds_prev->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1711 
1712                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1713                 ds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1714         }
1715         drc->drc_newsnapobj = drc->drc_ds->ds_phys->ds_prev_snap_obj;
1716         /*
1717          * Release the hold from dmu_recv_begin.  This must be done before
1718          * we return to open context, so that when we free the dataset's dnode,
1719          * we can evict its bonus buffer.
1720          */
1721         dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
1722         drc->drc_ds = NULL;
1723 }
1724 
1725 static int
1726 add_ds_to_guidmap(const char *name, avl_tree_t *guid_map, uint64_t snapobj)
1727 {
1728         dsl_pool_t *dp;
1729         dsl_dataset_t *snapds;
1730         guid_map_entry_t *gmep;
1731         int err;
1732 
1733         ASSERT(guid_map != NULL);
1734 
1735         err = dsl_pool_hold(name, FTAG, &dp);
1736         if (err != 0)
1737                 return (err);
1738         gmep = kmem_alloc(sizeof (*gmep), KM_SLEEP);
1739         err = dsl_dataset_hold_obj(dp, snapobj, gmep, &snapds);
1740         if (err == 0) {
1741                 gmep->guid = snapds->ds_phys->ds_guid;
1742                 gmep->gme_ds = snapds;
1743                 avl_add(guid_map, gmep);
1744                 dsl_dataset_long_hold(snapds, gmep);
1745         } else {
1746                 kmem_free(gmep, sizeof (*gmep));
1747         }
1748 
1749         dsl_pool_rele(dp, FTAG);
1750         return (err);
1751 }
1752 
1753 static int dmu_recv_end_modified_blocks = 3;
1754 
1755 static int
1756 dmu_recv_existing_end(dmu_recv_cookie_t *drc)
1757 {
1758         int error;
1759         char name[MAXNAMELEN];
1760 
1761 #ifdef _KERNEL
1762         /*
1763          * We will be destroying the ds; make sure its origin is unmounted if
1764          * necessary.
1765          */
1766         dsl_dataset_name(drc->drc_ds, name);
1767         zfs_destroy_unmount_origin(name);
1768 #endif
1769 
1770         error = dsl_sync_task(drc->drc_tofs,
1771             dmu_recv_end_check, dmu_recv_end_sync, drc,
1772             dmu_recv_end_modified_blocks);
1773 
1774         if (error != 0)
1775                 dmu_recv_cleanup_ds(drc);
1776         return (error);
1777 }
1778 
1779 static int
1780 dmu_recv_new_end(dmu_recv_cookie_t *drc)
1781 {
1782         int error;
1783 
1784         error = dsl_sync_task(drc->drc_tofs,
1785             dmu_recv_end_check, dmu_recv_end_sync, drc,
1786             dmu_recv_end_modified_blocks);
1787 
1788         if (error != 0) {
1789                 dmu_recv_cleanup_ds(drc);
1790         } else if (drc->drc_guid_to_ds_map != NULL) {
1791                 (void) add_ds_to_guidmap(drc->drc_tofs,
1792                     drc->drc_guid_to_ds_map,
1793                     drc->drc_newsnapobj);
1794         }
1795         return (error);
1796 }
1797 
1798 int
1799 dmu_recv_end(dmu_recv_cookie_t *drc, void *owner)
1800 {
1801         drc->drc_owner = owner;
1802 
1803         if (drc->drc_newfs)
1804                 return (dmu_recv_new_end(drc));
1805         else
1806                 return (dmu_recv_existing_end(drc));
1807 }
1808 
1809 /*
1810  * Return TRUE if this objset is currently being received into.
1811  */
1812 boolean_t
1813 dmu_objset_is_receiving(objset_t *os)
1814 {
1815         return (os->os_dsl_dataset != NULL &&
1816             os->os_dsl_dataset->ds_owner == dmu_recv_tag);
1817 }