sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  24  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
  25  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
  26  * Copyright (c) 2012, Martin Matuska <mm@FreeBSD.org>. All rights reserved.
  27  * Copyright 2014 HybridCluster. All rights reserved.
  28  * Copyright 2016 RackTop Systems.
  29  * Copyright (c) 2014 Integros [integros.com]
  30  */
  31
  32 #include <sys/dmu.h>
  33 #include <sys/dmu_impl.h>
  34 #include <sys/dmu_tx.h>
  35 #include <sys/dbuf.h>
  36 #include <sys/dnode.h>
  37 #include <sys/zfs_context.h>
  38 #include <sys/dmu_objset.h>
  39 #include <sys/dmu_traverse.h>
  40 #include <sys/dsl_dataset.h>
  41 #include <sys/dsl_dir.h>
  42 #include <sys/dsl_prop.h>
  43 #include <sys/dsl_pool.h>
  44 #include <sys/dsl_synctask.h>
  45 #include <sys/zfs_ioctl.h>
  46 #include <sys/zap.h>
  47 #include <sys/zio_checksum.h>
  48 #include <sys/zfs_znode.h>
  49 #include <zfs_fletcher.h>
  50 #include <sys/avl.h>
  51 #include <sys/ddt.h>
  52 #include <sys/zfs_onexit.h>
  53 #include <sys/dmu_send.h>
  54 #include <sys/dsl_destroy.h>
  55 #include <sys/blkptr.h>
  56 #include <sys/dsl_bookmark.h>
  57 #include <sys/zfeature.h>
  58 #include <sys/bqueue.h>
  59
  60 #ifdef __FreeBSD__
  61 #undef dump_write
  62 #define dump_write dmu_dump_write
  63 #endif
  64
  65 /* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
  66 int zfs_send_corrupt_data = B_FALSE;
  67 int zfs_send_queue_length = 16 * 1024 * 1024;
  68 int zfs_recv_queue_length = 16 * 1024 * 1024;
  69 /* Set this tunable to FALSE to disable setting of DRR_FLAG_FREERECORDS */
  70 int zfs_send_set_freerecords_bit = B_TRUE;
  71
  72 #ifdef _KERNEL
  73 TUNABLE_INT("vfs.zfs.send_set_freerecords_bit", &zfs_send_set_freerecords_bit);
  74 #endif
  75
  76 static char *dmu_recv_tag = "dmu_recv_tag";
  77 const char *recv_clone_name = "%recv";
  78
  79 /*
  80  * Use this to override the recordsize calculation for fast zfs send estimates.
  81  */
  82 uint64_t zfs_override_estimate_recordsize = 0;
  83
  84 #define BP_SPAN(datablkszsec, indblkshift, level) \
  85         (((uint64_t)datablkszsec) << (SPA_MINBLOCKSHIFT + \
  86         (level) * (indblkshift - SPA_BLKPTRSHIFT)))
  87
  88 static void byteswap_record(dmu_replay_record_t *drr);
  89
  90 struct send_thread_arg {
  91         bqueue_t        q;
  92         dsl_dataset_t   *ds;            /* Dataset to traverse */
  93         uint64_t        fromtxg;        /* Traverse from this txg */
  94         int             flags;          /* flags to pass to traverse_dataset */
  95         int             error_code;
  96         boolean_t       cancel;
  97         zbookmark_phys_t resume;
  98 };
  99
 100 struct send_block_record {
 101         boolean_t               eos_marker; /* Marks the end of the stream */
 102         blkptr_t                bp;
 103         zbookmark_phys_t        zb;
 104         uint8_t                 indblkshift;
 105         uint16_t                datablkszsec;
 106         bqueue_node_t           ln;
 107 };
 108
 109 static int
 110 dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
 111 {
 112         dsl_dataset_t *ds = dmu_objset_ds(dsp->dsa_os);
 113         struct uio auio;
 114         struct iovec aiov;
 115
 116         /*
 117          * The code does not rely on this (len being a multiple of 8).  We keep
 118          * this assertion because of the corresponding assertion in
 119          * receive_read().  Keeping this assertion ensures that we do not
 120          * inadvertently break backwards compatibility (causing the assertion
 121          * in receive_read() to trigger on old software).
 122          *
 123          * Removing the assertions could be rolled into a new feature that uses
 124          * data that isn't 8-byte aligned; if the assertions were removed, a
 125          * feature flag would have to be added.
 126          */
 127
 128         ASSERT0(len % 8);
 129
 130         aiov.iov_base = buf;
 131         aiov.iov_len = len;
 132         auio.uio_iov = &aiov;
 133         auio.uio_iovcnt = 1;
 134         auio.uio_resid = len;
 135         auio.uio_segflg = UIO_SYSSPACE;
 136         auio.uio_rw = UIO_WRITE;
 137         auio.uio_offset = (off_t)-1;
 138         auio.uio_td = dsp->dsa_td;
 139 #ifdef _KERNEL
 140         if (dsp->dsa_fp->f_type == DTYPE_VNODE)
 141                 bwillwrite();
 142         dsp->dsa_err = fo_write(dsp->dsa_fp, &auio, dsp->dsa_td->td_ucred, 0,
 143             dsp->dsa_td);
 144 #else
 145         fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
 146         dsp->dsa_err = EOPNOTSUPP;
 147 #endif
 148         mutex_enter(&ds->ds_sendstream_lock);
 149         *dsp->dsa_off += len;
 150         mutex_exit(&ds->ds_sendstream_lock);
 151
 152         return (dsp->dsa_err);
 153 }
 154
 155 /*
 156  * For all record types except BEGIN, fill in the checksum (overlaid in
 157  * drr_u.drr_checksum.drr_checksum).  The checksum verifies everything
 158  * up to the start of the checksum itself.
 159  */
 160 static int
 161 dump_record(dmu_sendarg_t *dsp, void *payload, int payload_len)
 162 {
 163         ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
 164             ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
 165         (void) fletcher_4_incremental_native(dsp->dsa_drr,
 166             offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
 167             &dsp->dsa_zc);
 168         if (dsp->dsa_drr->drr_type == DRR_BEGIN) {
 169                 dsp->dsa_sent_begin = B_TRUE;
 170         } else {
 171                 ASSERT(ZIO_CHECKSUM_IS_ZERO(&dsp->dsa_drr->drr_u.
 172                     drr_checksum.drr_checksum));
 173                 dsp->dsa_drr->drr_u.drr_checksum.drr_checksum = dsp->dsa_zc;
 174         }
 175         if (dsp->dsa_drr->drr_type == DRR_END) {
 176                 dsp->dsa_sent_end = B_TRUE;
 177         }
 178         (void) fletcher_4_incremental_native(&dsp->dsa_drr->
 179             drr_u.drr_checksum.drr_checksum,
 180             sizeof (zio_cksum_t), &dsp->dsa_zc);
 181         if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
 182                 return (SET_ERROR(EINTR));
 183         if (payload_len != 0) {
 184                 (void) fletcher_4_incremental_native(payload, payload_len,
 185                     &dsp->dsa_zc);
 186                 if (dump_bytes(dsp, payload, payload_len) != 0)
 187                         return (SET_ERROR(EINTR));
 188         }
 189         return (0);
 190 }
 191
 192 /*
 193  * Fill in the drr_free struct, or perform aggregation if the previous record is
 194  * also a free record, and the two are adjacent.
 195  *
 196  * Note that we send free records even for a full send, because we want to be
 197  * able to receive a full send as a clone, which requires a list of all the free
 198  * and freeobject records that were generated on the source.
 199  */
 200 static int
 201 dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 202     uint64_t length)
 203 {
 204         struct drr_free *drrf = &(dsp->dsa_drr->drr_u.drr_free);
 205
 206         /*
 207          * When we receive a free record, dbuf_free_range() assumes
 208          * that the receiving system doesn't have any dbufs in the range
 209          * being freed.  This is always true because there is a one-record
 210          * constraint: we only send one WRITE record for any given
 211          * object,offset.  We know that the one-record constraint is
 212          * true because we always send data in increasing order by
 213          * object,offset.
 214          *
 215          * If the increasing-order constraint ever changes, we should find
 216          * another way to assert that the one-record constraint is still
 217          * satisfied.
 218          */
 219         ASSERT(object > dsp->dsa_last_data_object ||
 220             (object == dsp->dsa_last_data_object &&
 221             offset > dsp->dsa_last_data_offset));
 222
 223         if (length != -1ULL && offset + length < offset)
 224                 length = -1ULL;
 225
 226         /*
 227          * If there is a pending op, but it's not PENDING_FREE, push it out,
 228          * since free block aggregation can only be done for blocks of the
 229          * same type (i.e., DRR_FREE records can only be aggregated with
 230          * other DRR_FREE records.  DRR_FREEOBJECTS records can only be
 231          * aggregated with other DRR_FREEOBJECTS records.
 232          */
 233         if (dsp->dsa_pending_op != PENDING_NONE &&
 234             dsp->dsa_pending_op != PENDING_FREE) {
 235                 if (dump_record(dsp, NULL, 0) != 0)
 236                         return (SET_ERROR(EINTR));
 237                 dsp->dsa_pending_op = PENDING_NONE;
 238         }
 239
 240         if (dsp->dsa_pending_op == PENDING_FREE) {
 241                 /*
 242                  * There should never be a PENDING_FREE if length is -1
 243                  * (because dump_dnode is the only place where this
 244                  * function is called with a -1, and only after flushing
 245                  * any pending record).
 246                  */
 247                 ASSERT(length != -1ULL);
 248                 /*
 249                  * Check to see whether this free block can be aggregated
 250                  * with pending one.
 251                  */
 252                 if (drrf->drr_object == object && drrf->drr_offset +
 253                     drrf->drr_length == offset) {
 254                         drrf->drr_length += length;
 255                         return (0);
 256                 } else {
 257                         /* not a continuation.  Push out pending record */
 258                         if (dump_record(dsp, NULL, 0) != 0)
 259                                 return (SET_ERROR(EINTR));
 260                         dsp->dsa_pending_op = PENDING_NONE;
 261                 }
 262         }
 263         /* create a FREE record and make it pending */
 264         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 265         dsp->dsa_drr->drr_type = DRR_FREE;
 266         drrf->drr_object = object;
 267         drrf->drr_offset = offset;
 268         drrf->drr_length = length;
 269         drrf->drr_toguid = dsp->dsa_toguid;
 270         if (length == -1ULL) {
 271                 if (dump_record(dsp, NULL, 0) != 0)
 272                         return (SET_ERROR(EINTR));
 273         } else {
 274                 dsp->dsa_pending_op = PENDING_FREE;
 275         }
 276
 277         return (0);
 278 }
 279
 280 static int
 281 dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
 282     uint64_t object, uint64_t offset, int lsize, int psize, const blkptr_t *bp,
 283     void *data)
 284 {
 285         uint64_t payload_size;
 286         struct drr_write *drrw = &(dsp->dsa_drr->drr_u.drr_write);
 287
 288         /*
 289          * We send data in increasing object, offset order.
 290          * See comment in dump_free() for details.
 291          */
 292         ASSERT(object > dsp->dsa_last_data_object ||
 293             (object == dsp->dsa_last_data_object &&
 294             offset > dsp->dsa_last_data_offset));
 295         dsp->dsa_last_data_object = object;
 296         dsp->dsa_last_data_offset = offset + lsize - 1;
 297
 298         /*
 299          * If there is any kind of pending aggregation (currently either
 300          * a grouping of free objects or free blocks), push it out to
 301          * the stream, since aggregation can't be done across operations
 302          * of different types.
 303          */
 304         if (dsp->dsa_pending_op != PENDING_NONE) {
 305                 if (dump_record(dsp, NULL, 0) != 0)
 306                         return (SET_ERROR(EINTR));
 307                 dsp->dsa_pending_op = PENDING_NONE;
 308         }
 309         /* write a WRITE record */
 310         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 311         dsp->dsa_drr->drr_type = DRR_WRITE;
 312         drrw->drr_object = object;
 313         drrw->drr_type = type;
 314         drrw->drr_offset = offset;
 315         drrw->drr_toguid = dsp->dsa_toguid;
 316         drrw->drr_logical_size = lsize;
 317
 318         /* only set the compression fields if the buf is compressed */
 319         if (lsize != psize) {
 320                 ASSERT(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_COMPRESSED);
 321                 ASSERT(!BP_IS_EMBEDDED(bp));
 322                 ASSERT(!BP_SHOULD_BYTESWAP(bp));
 323                 ASSERT(!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)));
 324                 ASSERT3U(BP_GET_COMPRESS(bp), !=, ZIO_COMPRESS_OFF);
 325                 ASSERT3S(psize, >, 0);
 326                 ASSERT3S(lsize, >=, psize);
 327
 328                 drrw->drr_compressiontype = BP_GET_COMPRESS(bp);
 329                 drrw->drr_compressed_size = psize;
 330                 payload_size = drrw->drr_compressed_size;
 331         } else {
 332                 payload_size = drrw->drr_logical_size;
 333         }
 334
 335         if (bp == NULL || BP_IS_EMBEDDED(bp)) {
 336                 /*
 337                  * There's no pre-computed checksum for partial-block
 338                  * writes or embedded BP's, so (like
 339                  * fletcher4-checkummed blocks) userland will have to
 340                  * compute a dedup-capable checksum itself.
 341                  */
 342                 drrw->drr_checksumtype = ZIO_CHECKSUM_OFF;
 343         } else {
 344                 drrw->drr_checksumtype = BP_GET_CHECKSUM(bp);
 345                 if (zio_checksum_table[drrw->drr_checksumtype].ci_flags &
 346                     ZCHECKSUM_FLAG_DEDUP)
 347                         drrw->drr_checksumflags |= DRR_CHECKSUM_DEDUP;
 348                 DDK_SET_LSIZE(&drrw->drr_key, BP_GET_LSIZE(bp));
 349                 DDK_SET_PSIZE(&drrw->drr_key, BP_GET_PSIZE(bp));
 350                 DDK_SET_COMPRESS(&drrw->drr_key, BP_GET_COMPRESS(bp));
 351                 drrw->drr_key.ddk_cksum = bp->blk_cksum;
 352         }
 353
 354         if (dump_record(dsp, data, payload_size) != 0)
 355                 return (SET_ERROR(EINTR));
 356         return (0);
 357 }
 358
 359 static int
 360 dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 361     int blksz, const blkptr_t *bp)
 362 {
 363         char buf[BPE_PAYLOAD_SIZE];
 364         struct drr_write_embedded *drrw =
 365             &(dsp->dsa_drr->drr_u.drr_write_embedded);
 366
 367         if (dsp->dsa_pending_op != PENDING_NONE) {
 368                 if (dump_record(dsp, NULL, 0) != 0)
 369                         return (EINTR);
 370                 dsp->dsa_pending_op = PENDING_NONE;
 371         }
 372
 373         ASSERT(BP_IS_EMBEDDED(bp));
 374
 375         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 376         dsp->dsa_drr->drr_type = DRR_WRITE_EMBEDDED;
 377         drrw->drr_object = object;
 378         drrw->drr_offset = offset;
 379         drrw->drr_length = blksz;
 380         drrw->drr_toguid = dsp->dsa_toguid;
 381         drrw->drr_compression = BP_GET_COMPRESS(bp);
 382         drrw->drr_etype = BPE_GET_ETYPE(bp);
 383         drrw->drr_lsize = BPE_GET_LSIZE(bp);
 384         drrw->drr_psize = BPE_GET_PSIZE(bp);
 385
 386         decode_embedded_bp_compressed(bp, buf);
 387
 388         if (dump_record(dsp, buf, P2ROUNDUP(drrw->drr_psize, 8)) != 0)
 389                 return (EINTR);
 390         return (0);
 391 }
 392
 393 static int
 394 dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
 395 {
 396         struct drr_spill *drrs = &(dsp->dsa_drr->drr_u.drr_spill);
 397
 398         if (dsp->dsa_pending_op != PENDING_NONE) {
 399                 if (dump_record(dsp, NULL, 0) != 0)
 400                         return (SET_ERROR(EINTR));
 401                 dsp->dsa_pending_op = PENDING_NONE;
 402         }
 403
 404         /* write a SPILL record */
 405         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 406         dsp->dsa_drr->drr_type = DRR_SPILL;
 407         drrs->drr_object = object;
 408         drrs->drr_length = blksz;
 409         drrs->drr_toguid = dsp->dsa_toguid;
 410
 411         if (dump_record(dsp, data, blksz) != 0)
 412                 return (SET_ERROR(EINTR));
 413         return (0);
 414 }
 415
 416 static int
 417 dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
 418 {
 419         struct drr_freeobjects *drrfo = &(dsp->dsa_drr->drr_u.drr_freeobjects);
 420
 421         /*
 422          * If there is a pending op, but it's not PENDING_FREEOBJECTS,
 423          * push it out, since free block aggregation can only be done for
 424          * blocks of the same type (i.e., DRR_FREE records can only be
 425          * aggregated with other DRR_FREE records.  DRR_FREEOBJECTS records
 426          * can only be aggregated with other DRR_FREEOBJECTS records.
 427          */
 428         if (dsp->dsa_pending_op != PENDING_NONE &&
 429             dsp->dsa_pending_op != PENDING_FREEOBJECTS) {
 430                 if (dump_record(dsp, NULL, 0) != 0)
 431                         return (SET_ERROR(EINTR));
 432                 dsp->dsa_pending_op = PENDING_NONE;
 433         }
 434         if (dsp->dsa_pending_op == PENDING_FREEOBJECTS) {
 435                 /*
 436                  * See whether this free object array can be aggregated
 437                  * with pending one
 438                  */
 439                 if (drrfo->drr_firstobj + drrfo->drr_numobjs == firstobj) {
 440                         drrfo->drr_numobjs += numobjs;
 441                         return (0);
 442                 } else {
 443                         /* can't be aggregated.  Push out pending record */
 444                         if (dump_record(dsp, NULL, 0) != 0)
 445                                 return (SET_ERROR(EINTR));
 446                         dsp->dsa_pending_op = PENDING_NONE;
 447                 }
 448         }
 449
 450         /* write a FREEOBJECTS record */
 451         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 452         dsp->dsa_drr->drr_type = DRR_FREEOBJECTS;
 453         drrfo->drr_firstobj = firstobj;
 454         drrfo->drr_numobjs = numobjs;
 455         drrfo->drr_toguid = dsp->dsa_toguid;
 456
 457         dsp->dsa_pending_op = PENDING_FREEOBJECTS;
 458
 459         return (0);
 460 }
 461
 462 static int
 463 dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
 464 {
 465         struct drr_object *drro = &(dsp->dsa_drr->drr_u.drr_object);
 466
 467         if (object < dsp->dsa_resume_object) {
 468                 /*
 469                  * Note: when resuming, we will visit all the dnodes in
 470                  * the block of dnodes that we are resuming from.  In
 471                  * this case it's unnecessary to send the dnodes prior to
 472                  * the one we are resuming from.  We should be at most one
 473                  * block's worth of dnodes behind the resume point.
 474                  */
 475                 ASSERT3U(dsp->dsa_resume_object - object, <,
 476                     1 << (DNODE_BLOCK_SHIFT - DNODE_SHIFT));
 477                 return (0);
 478         }
 479
 480         if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
 481                 return (dump_freeobjects(dsp, object, 1));
 482
 483         if (dsp->dsa_pending_op != PENDING_NONE) {
 484                 if (dump_record(dsp, NULL, 0) != 0)
 485                         return (SET_ERROR(EINTR));
 486                 dsp->dsa_pending_op = PENDING_NONE;
 487         }
 488
 489         /* write an OBJECT record */
 490         bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
 491         dsp->dsa_drr->drr_type = DRR_OBJECT;
 492         drro->drr_object = object;
 493         drro->drr_type = dnp->dn_type;
 494         drro->drr_bonustype = dnp->dn_bonustype;
 495         drro->drr_blksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 496         drro->drr_bonuslen = dnp->dn_bonuslen;
 497         drro->drr_checksumtype = dnp->dn_checksum;
 498         drro->drr_compress = dnp->dn_compress;
 499         drro->drr_toguid = dsp->dsa_toguid;
 500
 501         if (!(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
 502             drro->drr_blksz > SPA_OLD_MAXBLOCKSIZE)
 503                 drro->drr_blksz = SPA_OLD_MAXBLOCKSIZE;
 504
 505         if (dump_record(dsp, DN_BONUS(dnp),
 506             P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0) {
 507                 return (SET_ERROR(EINTR));
 508         }
 509
 510         /* Free anything past the end of the file. */
 511         if (dump_free(dsp, object, (dnp->dn_maxblkid + 1) *
 512             (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL) != 0)
 513                 return (SET_ERROR(EINTR));
 514         if (dsp->dsa_err != 0)
 515                 return (SET_ERROR(EINTR));
 516         return (0);
 517 }
 518
 519 static boolean_t
 520 backup_do_embed(dmu_sendarg_t *dsp, const blkptr_t *bp)
 521 {
 522         if (!BP_IS_EMBEDDED(bp))
 523                 return (B_FALSE);
 524
 525         /*
 526          * Compression function must be legacy, or explicitly enabled.
 527          */
 528         if ((BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_LEGACY_FUNCTIONS &&
 529             !(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_LZ4)))
 530                 return (B_FALSE);
 531
 532         /*
 533          * Embed type must be explicitly enabled.
 534          */
 535         switch (BPE_GET_ETYPE(bp)) {
 536         case BP_EMBEDDED_TYPE_DATA:
 537                 if (dsp->dsa_featureflags & DMU_BACKUP_FEATURE_EMBED_DATA)
 538                         return (B_TRUE);
 539                 break;
 540         default:
 541                 return (B_FALSE);
 542         }
 543         return (B_FALSE);
 544 }
 545
 546 /*
 547  * This is the callback function to traverse_dataset that acts as the worker
 548  * thread for dmu_send_impl.
 549  */
 550 /*ARGSUSED*/
 551 static int
 552 send_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 553     const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg)
 554 {
 555         struct send_thread_arg *sta = arg;
 556         struct send_block_record *record;
 557         uint64_t record_size;
 558         int err = 0;
 559
 560         ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
 561             zb->zb_object >= sta->resume.zb_object);
 562
 563         if (sta->cancel)
 564                 return (SET_ERROR(EINTR));
 565
 566         if (bp == NULL) {
 567                 ASSERT3U(zb->zb_level, ==, ZB_DNODE_LEVEL);
 568                 return (0);
 569         } else if (zb->zb_level < 0) {
 570                 return (0);
 571         }
 572
 573         record = kmem_zalloc(sizeof (struct send_block_record), KM_SLEEP);
 574         record->eos_marker = B_FALSE;
 575         record->bp = *bp;
 576         record->zb = *zb;
 577         record->indblkshift = dnp->dn_indblkshift;
 578         record->datablkszsec = dnp->dn_datablkszsec;
 579         record_size = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
 580         bqueue_enqueue(&sta->q, record, record_size);
 581
 582         return (err);
 583 }
 584
 585 /*
 586  * This function kicks off the traverse_dataset.  It also handles setting the
 587  * error code of the thread in case something goes wrong, and pushes the End of
 588  * Stream record when the traverse_dataset call has finished.  If there is no
 589  * dataset to traverse, the thread immediately pushes End of Stream marker.
 590  */
 591 static void
 592 send_traverse_thread(void *arg)
 593 {
 594         struct send_thread_arg *st_arg = arg;
 595         int err;
 596         struct send_block_record *data;
 597
 598         if (st_arg->ds != NULL) {
 599                 err = traverse_dataset_resume(st_arg->ds,
 600                     st_arg->fromtxg, &st_arg->resume,
 601                     st_arg->flags, send_cb, st_arg);
 602
 603                 if (err != EINTR)
 604                         st_arg->error_code = err;
 605         }
 606         data = kmem_zalloc(sizeof (*data), KM_SLEEP);
 607         data->eos_marker = B_TRUE;
 608         bqueue_enqueue(&st_arg->q, data, 1);
 609         thread_exit();
 610 }
 611
 612 /*
 613  * This function actually handles figuring out what kind of record needs to be
 614  * dumped, reading the data (which has hopefully been prefetched), and calling
 615  * the appropriate helper function.
 616  */
 617 static int
 618 do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
 619 {
 620         dsl_dataset_t *ds = dmu_objset_ds(dsa->dsa_os);
 621         const blkptr_t *bp = &data->bp;
 622         const zbookmark_phys_t *zb = &data->zb;
 623         uint8_t indblkshift = data->indblkshift;
 624         uint16_t dblkszsec = data->datablkszsec;
 625         spa_t *spa = ds->ds_dir->dd_pool->dp_spa;
 626         dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
 627         int err = 0;
 628
 629         ASSERT3U(zb->zb_level, >=, 0);
 630
 631         ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
 632             zb->zb_object >= dsa->dsa_resume_object);
 633
 634         if (zb->zb_object != DMU_META_DNODE_OBJECT &&
 635             DMU_OBJECT_IS_SPECIAL(zb->zb_object)) {
 636                 return (0);
 637         } else if (BP_IS_HOLE(bp) &&
 638             zb->zb_object == DMU_META_DNODE_OBJECT) {
 639                 uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
 640                 uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
 641                 err = dump_freeobjects(dsa, dnobj, span >> DNODE_SHIFT);
 642         } else if (BP_IS_HOLE(bp)) {
 643                 uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
 644                 uint64_t offset = zb->zb_blkid * span;
 645                 err = dump_free(dsa, zb->zb_object, offset, span);
 646         } else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
 647                 return (0);
 648         } else if (type == DMU_OT_DNODE) {
 649                 int blksz = BP_GET_LSIZE(bp);
 650                 arc_flags_t aflags = ARC_FLAG_WAIT;
 651                 arc_buf_t *abuf;
 652
 653                 ASSERT0(zb->zb_level);
 654
 655                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 656                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
 657                     &aflags, zb) != 0)
 658                         return (SET_ERROR(EIO));
 659
 660                 dnode_phys_t *blk = abuf->b_data;
 661                 uint64_t dnobj = zb->zb_blkid * (blksz >> DNODE_SHIFT);
 662                 for (int i = 0; i < blksz >> DNODE_SHIFT; i++) {
 663                         err = dump_dnode(dsa, dnobj + i, blk + i);
 664                         if (err != 0)
 665                                 break;
 666                 }
 667                 arc_buf_destroy(abuf, &abuf);
 668         } else if (type == DMU_OT_SA) {
 669                 arc_flags_t aflags = ARC_FLAG_WAIT;
 670                 arc_buf_t *abuf;
 671                 int blksz = BP_GET_LSIZE(bp);
 672
 673                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 674                     ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
 675                     &aflags, zb) != 0)
 676                         return (SET_ERROR(EIO));
 677
 678                 err = dump_spill(dsa, zb->zb_object, blksz, abuf->b_data);
 679                 arc_buf_destroy(abuf, &abuf);
 680         } else if (backup_do_embed(dsa, bp)) {
 681                 /* it's an embedded level-0 block of a regular object */
 682                 int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
 683                 ASSERT0(zb->zb_level);
 684                 err = dump_write_embedded(dsa, zb->zb_object,
 685                     zb->zb_blkid * blksz, blksz, bp);
 686         } else {
 687                 /* it's a level-0 block of a regular object */
 688                 arc_flags_t aflags = ARC_FLAG_WAIT;
 689                 arc_buf_t *abuf;
 690                 int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
 691                 uint64_t offset;
 692
 693                 /*
 694                  * If we have large blocks stored on disk but the send flags
 695                  * don't allow us to send large blocks, we split the data from
 696                  * the arc buf into chunks.
 697                  */
 698                 boolean_t split_large_blocks = blksz > SPA_OLD_MAXBLOCKSIZE &&
 699                     !(dsa->dsa_featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS);
 700                 /*
 701                  * We should only request compressed data from the ARC if all
 702                  * the following are true:
 703                  *  - stream compression was requested
 704                  *  - we aren't splitting large blocks into smaller chunks
 705                  *  - the data won't need to be byteswapped before sending
 706                  *  - this isn't an embedded block
 707                  *  - this isn't metadata (if receiving on a different endian
 708                  *    system it can be byteswapped more easily)
 709                  */
 710                 boolean_t request_compressed =
 711                     (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_COMPRESSED) &&
 712                     !split_large_blocks && !BP_SHOULD_BYTESWAP(bp) &&
 713                     !BP_IS_EMBEDDED(bp) && !DMU_OT_IS_METADATA(BP_GET_TYPE(bp));
 714
 715                 ASSERT0(zb->zb_level);
 716                 ASSERT(zb->zb_object > dsa->dsa_resume_object ||
 717                     (zb->zb_object == dsa->dsa_resume_object &&
 718                     zb->zb_blkid * blksz >= dsa->dsa_resume_offset));
 719
 720                 ASSERT0(zb->zb_level);
 721                 ASSERT(zb->zb_object > dsa->dsa_resume_object ||
 722                     (zb->zb_object == dsa->dsa_resume_object &&
 723                     zb->zb_blkid * blksz >= dsa->dsa_resume_offset));
 724
 725                 ASSERT3U(blksz, ==, BP_GET_LSIZE(bp));
 726
 727                 enum zio_flag zioflags = ZIO_FLAG_CANFAIL;
 728                 if (request_compressed)
 729                         zioflags |= ZIO_FLAG_RAW;
 730                 if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
 731                     ZIO_PRIORITY_ASYNC_READ, zioflags, &aflags, zb) != 0) {
 732                         if (zfs_send_corrupt_data) {
 733                                 /* Send a block filled with 0x"zfs badd bloc" */
 734                                 abuf = arc_alloc_buf(spa, &abuf, ARC_BUFC_DATA,
 735                                     blksz);
 736                                 uint64_t *ptr;
 737                                 for (ptr = abuf->b_data;
 738                                     (char *)ptr < (char *)abuf->b_data + blksz;
 739                                     ptr++)
 740                                         *ptr = 0x2f5baddb10cULL;
 741                         } else {
 742                                 return (SET_ERROR(EIO));
 743                         }
 744                 }
 745
 746                 offset = zb->zb_blkid * blksz;
 747
 748                 if (split_large_blocks) {
 749                         ASSERT3U(arc_get_compression(abuf), ==,
 750                             ZIO_COMPRESS_OFF);
 751                         char *buf = abuf->b_data;
 752                         while (blksz > 0 && err == 0) {
 753                                 int n = MIN(blksz, SPA_OLD_MAXBLOCKSIZE);
 754                                 err = dump_write(dsa, type, zb->zb_object,
 755                                     offset, n, n, NULL, buf);
 756                                 offset += n;
 757                                 buf += n;
 758                                 blksz -= n;
 759                         }
 760                 } else {
 761                         err = dump_write(dsa, type, zb->zb_object, offset,
 762                             blksz, arc_buf_size(abuf), bp, abuf->b_data);
 763                 }
 764                 arc_buf_destroy(abuf, &abuf);
 765         }
 766
 767         ASSERT(err == 0 || err == EINTR);
 768         return (err);
 769 }
 770
 771 /*
 772  * Pop the new data off the queue, and free the old data.
 773  */
 774 static struct send_block_record *
 775 get_next_record(bqueue_t *bq, struct send_block_record *data)
 776 {
 777         struct send_block_record *tmp = bqueue_dequeue(bq);
 778         kmem_free(data, sizeof (*data));
 779         return (tmp);
 780 }
 781
 782 /*
 783  * Actually do the bulk of the work in a zfs send.
 784  *
 785  * Note: Releases dp using the specified tag.
 786  */
 787 static int
 788 dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
 789     zfs_bookmark_phys_t *ancestor_zb, boolean_t is_clone,
 790     boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
 791     int outfd, uint64_t resumeobj, uint64_t resumeoff,
 792 #ifdef illumos
 793     vnode_t *vp, offset_t *off)
 794 #else
 795     struct file *fp, offset_t *off)
 796 #endif
 797 {
 798         objset_t *os;
 799         dmu_replay_record_t *drr;
 800         dmu_sendarg_t *dsp;
 801         int err;
 802         uint64_t fromtxg = 0;
 803         uint64_t featureflags = 0;
 804         struct send_thread_arg to_arg = { 0 };
 805
 806         err = dmu_objset_from_ds(to_ds, &os);
 807         if (err != 0) {
 808                 dsl_pool_rele(dp, tag);
 809                 return (err);
 810         }
 811
 812         drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
 813         drr->drr_type = DRR_BEGIN;
 814         drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
 815         DMU_SET_STREAM_HDRTYPE(drr->drr_u.drr_begin.drr_versioninfo,
 816             DMU_SUBSTREAM);
 817
 818 #ifdef _KERNEL
 819         if (dmu_objset_type(os) == DMU_OST_ZFS) {
 820                 uint64_t version;
 821                 if (zfs_get_zplprop(os, ZFS_PROP_VERSION, &version) != 0) {
 822                         kmem_free(drr, sizeof (dmu_replay_record_t));
 823                         dsl_pool_rele(dp, tag);
 824                         return (SET_ERROR(EINVAL));
 825                 }
 826                 if (version >= ZPL_VERSION_SA) {
 827                         featureflags |= DMU_BACKUP_FEATURE_SA_SPILL;
 828                 }
 829         }
 830 #endif
 831
 832         if (large_block_ok && to_ds->ds_feature_inuse[SPA_FEATURE_LARGE_BLOCKS])
 833                 featureflags |= DMU_BACKUP_FEATURE_LARGE_BLOCKS;
 834         if (embedok &&
 835             spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA)) {
 836                 featureflags |= DMU_BACKUP_FEATURE_EMBED_DATA;
 837                 if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
 838                         featureflags |= DMU_BACKUP_FEATURE_LZ4;
 839         }
 840         if (compressok) {
 841                 featureflags |= DMU_BACKUP_FEATURE_COMPRESSED;
 842         }
 843         if ((featureflags &
 844             (DMU_BACKUP_FEATURE_EMBED_DATA | DMU_BACKUP_FEATURE_COMPRESSED)) !=
 845             0 && spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS)) {
 846                 featureflags |= DMU_BACKUP_FEATURE_LZ4;
 847         }
 848
 849         if (resumeobj != 0 || resumeoff != 0) {
 850                 featureflags |= DMU_BACKUP_FEATURE_RESUMING;
 851         }
 852
 853         DMU_SET_FEATUREFLAGS(drr->drr_u.drr_begin.drr_versioninfo,
 854             featureflags);
 855
 856         drr->drr_u.drr_begin.drr_creation_time =
 857             dsl_dataset_phys(to_ds)->ds_creation_time;
 858         drr->drr_u.drr_begin.drr_type = dmu_objset_type(os);
 859         if (is_clone)
 860                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
 861         drr->drr_u.drr_begin.drr_toguid = dsl_dataset_phys(to_ds)->ds_guid;
 862         if (dsl_dataset_phys(to_ds)->ds_flags & DS_FLAG_CI_DATASET)
 863                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CI_DATA;
 864         if (zfs_send_set_freerecords_bit)
 865                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_FREERECORDS;
 866
 867         if (ancestor_zb != NULL) {
 868                 drr->drr_u.drr_begin.drr_fromguid =
 869                     ancestor_zb->zbm_guid;
 870                 fromtxg = ancestor_zb->zbm_creation_txg;
 871         }
 872         dsl_dataset_name(to_ds, drr->drr_u.drr_begin.drr_toname);
 873         if (!to_ds->ds_is_snapshot) {
 874                 (void) strlcat(drr->drr_u.drr_begin.drr_toname, "@--head--",
 875                     sizeof (drr->drr_u.drr_begin.drr_toname));
 876         }
 877
 878         dsp = kmem_zalloc(sizeof (dmu_sendarg_t), KM_SLEEP);
 879
 880         dsp->dsa_drr = drr;
 881         dsp->dsa_outfd = outfd;
 882         dsp->dsa_proc = curproc;
 883         dsp->dsa_td = curthread;
 884         dsp->dsa_fp = fp;
 885         dsp->dsa_os = os;
 886         dsp->dsa_off = off;
 887         dsp->dsa_toguid = dsl_dataset_phys(to_ds)->ds_guid;
 888         dsp->dsa_pending_op = PENDING_NONE;
 889         dsp->dsa_featureflags = featureflags;
 890         dsp->dsa_resume_object = resumeobj;
 891         dsp->dsa_resume_offset = resumeoff;
 892
 893         mutex_enter(&to_ds->ds_sendstream_lock);
 894         list_insert_head(&to_ds->ds_sendstreams, dsp);
 895         mutex_exit(&to_ds->ds_sendstream_lock);
 896
 897         dsl_dataset_long_hold(to_ds, FTAG);
 898         dsl_pool_rele(dp, tag);
 899
 900         void *payload = NULL;
 901         size_t payload_len = 0;
 902         if (resumeobj != 0 || resumeoff != 0) {
 903                 dmu_object_info_t to_doi;
 904                 err = dmu_object_info(os, resumeobj, &to_doi);
 905                 if (err != 0)
 906                         goto out;
 907                 SET_BOOKMARK(&to_arg.resume, to_ds->ds_object, resumeobj, 0,
 908                     resumeoff / to_doi.doi_data_block_size);
 909
 910                 nvlist_t *nvl = fnvlist_alloc();
 911                 fnvlist_add_uint64(nvl, "resume_object", resumeobj);
 912                 fnvlist_add_uint64(nvl, "resume_offset", resumeoff);
 913                 payload = fnvlist_pack(nvl, &payload_len);
 914                 drr->drr_payloadlen = payload_len;
 915                 fnvlist_free(nvl);
 916         }
 917
 918         err = dump_record(dsp, payload, payload_len);
 919         fnvlist_pack_free(payload, payload_len);
 920         if (err != 0) {
 921                 err = dsp->dsa_err;
 922                 goto out;
 923         }
 924
 925         err = bqueue_init(&to_arg.q, zfs_send_queue_length,
 926             offsetof(struct send_block_record, ln));
 927         to_arg.error_code = 0;
 928         to_arg.cancel = B_FALSE;
 929         to_arg.ds = to_ds;
 930         to_arg.fromtxg = fromtxg;
 931         to_arg.flags = TRAVERSE_PRE | TRAVERSE_PREFETCH;
 932         (void) thread_create(NULL, 0, send_traverse_thread, &to_arg, 0, &p0,
 933             TS_RUN, minclsyspri);
 934
 935         struct send_block_record *to_data;
 936         to_data = bqueue_dequeue(&to_arg.q);
 937
 938         while (!to_data->eos_marker && err == 0) {
 939                 err = do_dump(dsp, to_data);
 940                 to_data = get_next_record(&to_arg.q, to_data);
 941                 if (issig(JUSTLOOKING) && issig(FORREAL))
 942                         err = EINTR;
 943         }
 944
 945         if (err != 0) {
 946                 to_arg.cancel = B_TRUE;
 947                 while (!to_data->eos_marker) {
 948                         to_data = get_next_record(&to_arg.q, to_data);
 949                 }
 950         }
 951         kmem_free(to_data, sizeof (*to_data));
 952
 953         bqueue_destroy(&to_arg.q);
 954
 955         if (err == 0 && to_arg.error_code != 0)
 956                 err = to_arg.error_code;
 957
 958         if (err != 0)
 959                 goto out;
 960
 961         if (dsp->dsa_pending_op != PENDING_NONE)
 962                 if (dump_record(dsp, NULL, 0) != 0)
 963                         err = SET_ERROR(EINTR);
 964
 965         if (err != 0) {
 966                 if (err == EINTR && dsp->dsa_err != 0)
 967                         err = dsp->dsa_err;
 968                 goto out;
 969         }
 970
 971         bzero(drr, sizeof (dmu_replay_record_t));
 972         drr->drr_type = DRR_END;
 973         drr->drr_u.drr_end.drr_checksum = dsp->dsa_zc;
 974         drr->drr_u.drr_end.drr_toguid = dsp->dsa_toguid;
 975
 976         if (dump_record(dsp, NULL, 0) != 0)
 977                 err = dsp->dsa_err;
 978
 979 out:
 980         mutex_enter(&to_ds->ds_sendstream_lock);
 981         list_remove(&to_ds->ds_sendstreams, dsp);
 982         mutex_exit(&to_ds->ds_sendstream_lock);
 983
 984         VERIFY(err != 0 || (dsp->dsa_sent_begin && dsp->dsa_sent_end));
 985
 986         kmem_free(drr, sizeof (dmu_replay_record_t));
 987         kmem_free(dsp, sizeof (dmu_sendarg_t));
 988
 989         dsl_dataset_long_rele(to_ds, FTAG);
 990
 991         return (err);
 992 }
 993
 994 int
 995 dmu_send_obj(const char *pool, uint64_t tosnap, uint64_t fromsnap,
 996     boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
 997 #ifdef illumos
 998     int outfd, vnode_t *vp, offset_t *off)
 999 #else
1000     int outfd, struct file *fp, offset_t *off)
1001 #endif
1002 {
1003         dsl_pool_t *dp;
1004         dsl_dataset_t *ds;
1005         dsl_dataset_t *fromds = NULL;
1006         int err;
1007
1008         err = dsl_pool_hold(pool, FTAG, &dp);
1009         if (err != 0)
1010                 return (err);
1011
1012         err = dsl_dataset_hold_obj(dp, tosnap, FTAG, &ds);
1013         if (err != 0) {
1014                 dsl_pool_rele(dp, FTAG);
1015                 return (err);
1016         }
1017
1018         if (fromsnap != 0) {
1019                 zfs_bookmark_phys_t zb;
1020                 boolean_t is_clone;
1021
1022                 err = dsl_dataset_hold_obj(dp, fromsnap, FTAG, &fromds);
1023                 if (err != 0) {
1024                         dsl_dataset_rele(ds, FTAG);
1025                         dsl_pool_rele(dp, FTAG);
1026                         return (err);
1027                 }
1028                 if (!dsl_dataset_is_before(ds, fromds, 0))
1029                         err = SET_ERROR(EXDEV);
1030                 zb.zbm_creation_time =
1031                     dsl_dataset_phys(fromds)->ds_creation_time;
1032                 zb.zbm_creation_txg = dsl_dataset_phys(fromds)->ds_creation_txg;
1033                 zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
1034                 is_clone = (fromds->ds_dir != ds->ds_dir);
1035                 dsl_dataset_rele(fromds, FTAG);
1036                 err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
1037                     embedok, large_block_ok, compressok, outfd, 0, 0, fp, off);
1038         } else {
1039                 err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
1040                     embedok, large_block_ok, compressok, outfd, 0, 0, fp, off);
1041         }
1042         dsl_dataset_rele(ds, FTAG);
1043         return (err);
1044 }
1045
1046 int
1047 dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
1048     boolean_t large_block_ok, boolean_t compressok, int outfd,
1049     uint64_t resumeobj, uint64_t resumeoff,
1050 #ifdef illumos
1051     vnode_t *vp, offset_t *off)
1052 #else
1053     struct file *fp, offset_t *off)
1054 #endif
1055 {
1056         dsl_pool_t *dp;
1057         dsl_dataset_t *ds;
1058         int err;
1059         boolean_t owned = B_FALSE;
1060
1061         if (fromsnap != NULL && strpbrk(fromsnap, "@#") == NULL)
1062                 return (SET_ERROR(EINVAL));
1063
1064         err = dsl_pool_hold(tosnap, FTAG, &dp);
1065         if (err != 0)
1066                 return (err);
1067
1068         if (strchr(tosnap, '@') == NULL && spa_writeable(dp->dp_spa)) {
1069                 /*
1070                  * We are sending a filesystem or volume.  Ensure
1071                  * that it doesn't change by owning the dataset.
1072                  */
1073                 err = dsl_dataset_own(dp, tosnap, FTAG, &ds);
1074                 owned = B_TRUE;
1075         } else {
1076                 err = dsl_dataset_hold(dp, tosnap, FTAG, &ds);
1077         }
1078         if (err != 0) {
1079                 dsl_pool_rele(dp, FTAG);
1080                 return (err);
1081         }
1082
1083         if (fromsnap != NULL) {
1084                 zfs_bookmark_phys_t zb;
1085                 boolean_t is_clone = B_FALSE;
1086                 int fsnamelen = strchr(tosnap, '@') - tosnap;
1087
1088                 /*
1089                  * If the fromsnap is in a different filesystem, then
1090                  * mark the send stream as a clone.
1091                  */
1092                 if (strncmp(tosnap, fromsnap, fsnamelen) != 0 ||
1093                     (fromsnap[fsnamelen] != '@' &&
1094                     fromsnap[fsnamelen] != '#')) {
1095                         is_clone = B_TRUE;
1096                 }
1097
1098                 if (strchr(fromsnap, '@')) {
1099                         dsl_dataset_t *fromds;
1100                         err = dsl_dataset_hold(dp, fromsnap, FTAG, &fromds);
1101                         if (err == 0) {
1102                                 if (!dsl_dataset_is_before(ds, fromds, 0))
1103                                         err = SET_ERROR(EXDEV);
1104                                 zb.zbm_creation_time =
1105                                     dsl_dataset_phys(fromds)->ds_creation_time;
1106                                 zb.zbm_creation_txg =
1107                                     dsl_dataset_phys(fromds)->ds_creation_txg;
1108                                 zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
1109                                 is_clone = (ds->ds_dir != fromds->ds_dir);
1110                                 dsl_dataset_rele(fromds, FTAG);
1111                         }
1112                 } else {
1113                         err = dsl_bookmark_lookup(dp, fromsnap, ds, &zb);
1114                 }
1115                 if (err != 0) {
1116                         dsl_dataset_rele(ds, FTAG);
1117                         dsl_pool_rele(dp, FTAG);
1118                         return (err);
1119                 }
1120                 err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
1121                     embedok, large_block_ok, compressok,
1122                     outfd, resumeobj, resumeoff, fp, off);
1123         } else {
1124                 err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
1125                     embedok, large_block_ok, compressok,
1126                     outfd, resumeobj, resumeoff, fp, off);
1127         }
1128         if (owned)
1129                 dsl_dataset_disown(ds, FTAG);
1130         else
1131                 dsl_dataset_rele(ds, FTAG);
1132         return (err);
1133 }
1134
1135 static int
1136 dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
1137     uint64_t compressed, boolean_t stream_compressed, uint64_t *sizep)
1138 {
1139         int err = 0;
1140         uint64_t size;
1141         /*
1142          * Assume that space (both on-disk and in-stream) is dominated by
1143          * data.  We will adjust for indirect blocks and the copies property,
1144          * but ignore per-object space used (eg, dnodes and DRR_OBJECT records).
1145          */
1146         uint64_t recordsize;
1147         uint64_t record_count;
1148         objset_t *os;
1149         VERIFY0(dmu_objset_from_ds(ds, &os));
1150
1151         /* Assume all (uncompressed) blocks are recordsize. */
1152         if (zfs_override_estimate_recordsize != 0) {
1153                 recordsize = zfs_override_estimate_recordsize;
1154         } else if (os->os_phys->os_type == DMU_OST_ZVOL) {
1155                 err = dsl_prop_get_int_ds(ds,
1156                     zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &recordsize);
1157         } else {
1158                 err = dsl_prop_get_int_ds(ds,
1159                     zfs_prop_to_name(ZFS_PROP_RECORDSIZE), &recordsize);
1160         }
1161         if (err != 0)
1162                 return (err);
1163         record_count = uncompressed / recordsize;
1164
1165         /*
1166          * If we're estimating a send size for a compressed stream, use the
1167          * compressed data size to estimate the stream size. Otherwise, use the
1168          * uncompressed data size.
1169          */
1170         size = stream_compressed ? compressed : uncompressed;
1171
1172         /*
1173          * Subtract out approximate space used by indirect blocks.
1174          * Assume most space is used by data blocks (non-indirect, non-dnode).
1175          * Assume no ditto blocks or internal fragmentation.
1176          *
1177          * Therefore, space used by indirect blocks is sizeof(blkptr_t) per
1178          * block.
1179          */
1180         size -= record_count * sizeof (blkptr_t);
1181
1182         /* Add in the space for the record associated with each block. */
1183         size += record_count * sizeof (dmu_replay_record_t);
1184
1185         *sizep = size;
1186
1187         return (0);
1188 }
1189
1190 int
1191 dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds,
1192     boolean_t stream_compressed, uint64_t *sizep)
1193 {
1194         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1195         int err;
1196         uint64_t uncomp, comp;
1197
1198         ASSERT(dsl_pool_config_held(dp));
1199
1200         /* tosnap must be a snapshot */
1201         if (!ds->ds_is_snapshot)
1202                 return (SET_ERROR(EINVAL));
1203
1204         /* fromsnap, if provided, must be a snapshot */
1205         if (fromds != NULL && !fromds->ds_is_snapshot)
1206                 return (SET_ERROR(EINVAL));
1207
1208         /*
1209          * fromsnap must be an earlier snapshot from the same fs as tosnap,
1210          * or the origin's fs.
1211          */
1212         if (fromds != NULL && !dsl_dataset_is_before(ds, fromds, 0))
1213                 return (SET_ERROR(EXDEV));
1214
1215         /* Get compressed and uncompressed size estimates of changed data. */
1216         if (fromds == NULL) {
1217                 uncomp = dsl_dataset_phys(ds)->ds_uncompressed_bytes;
1218                 comp = dsl_dataset_phys(ds)->ds_compressed_bytes;
1219         } else {
1220                 uint64_t used;
1221                 err = dsl_dataset_space_written(fromds, ds,
1222                     &used, &comp, &uncomp);
1223                 if (err != 0)
1224                         return (err);
1225         }
1226
1227         err = dmu_adjust_send_estimate_for_indirects(ds, uncomp, comp,
1228             stream_compressed, sizep);
1229         /*
1230          * Add the size of the BEGIN and END records to the estimate.
1231          */
1232         *sizep += 2 * sizeof (dmu_replay_record_t);
1233         return (err);
1234 }
1235
1236 struct calculate_send_arg {
1237         uint64_t uncompressed;
1238         uint64_t compressed;
1239 };
1240
1241 /*
1242  * Simple callback used to traverse the blocks of a snapshot and sum their
1243  * uncompressed and compressed sizes.
1244  */
1245 /* ARGSUSED */
1246 static int
1247 dmu_calculate_send_traversal(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1248     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
1249 {
1250         struct calculate_send_arg *space = arg;
1251         if (bp != NULL && !BP_IS_HOLE(bp)) {
1252                 space->uncompressed += BP_GET_UCSIZE(bp);
1253                 space->compressed += BP_GET_PSIZE(bp);
1254         }
1255         return (0);
1256 }
1257
1258 /*
1259  * Given a desination snapshot and a TXG, calculate the approximate size of a
1260  * send stream sent from that TXG. from_txg may be zero, indicating that the
1261  * whole snapshot will be sent.
1262  */
1263 int
1264 dmu_send_estimate_from_txg(dsl_dataset_t *ds, uint64_t from_txg,
1265     boolean_t stream_compressed, uint64_t *sizep)
1266 {
1267         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1268         int err;
1269         struct calculate_send_arg size = { 0 };
1270
1271         ASSERT(dsl_pool_config_held(dp));
1272
1273         /* tosnap must be a snapshot */
1274         if (!ds->ds_is_snapshot)
1275                 return (SET_ERROR(EINVAL));
1276
1277         /* verify that from_txg is before the provided snapshot was taken */
1278         if (from_txg >= dsl_dataset_phys(ds)->ds_creation_txg) {
1279                 return (SET_ERROR(EXDEV));
1280         }
1281
1282         /*
1283          * traverse the blocks of the snapshot with birth times after
1284          * from_txg, summing their uncompressed size
1285          */
1286         err = traverse_dataset(ds, from_txg, TRAVERSE_POST,
1287             dmu_calculate_send_traversal, &size);
1288         if (err)
1289                 return (err);
1290
1291         err = dmu_adjust_send_estimate_for_indirects(ds, size.uncompressed,
1292             size.compressed, stream_compressed, sizep);
1293         return (err);
1294 }
1295
1296 typedef struct dmu_recv_begin_arg {
1297         const char *drba_origin;
1298         dmu_recv_cookie_t *drba_cookie;
1299         cred_t *drba_cred;
1300         uint64_t drba_snapobj;
1301 } dmu_recv_begin_arg_t;
1302
1303 static int
1304 recv_begin_check_existing_impl(dmu_recv_begin_arg_t *drba, dsl_dataset_t *ds,
1305     uint64_t fromguid)
1306 {
1307         uint64_t val;
1308         int error;
1309         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1310
1311         /* temporary clone name must not exist */
1312         error = zap_lookup(dp->dp_meta_objset,
1313             dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, recv_clone_name,
1314             8, 1, &val);
1315         if (error != ENOENT)
1316                 return (error == 0 ? EBUSY : error);
1317
1318         /* new snapshot name must not exist */
1319         error = zap_lookup(dp->dp_meta_objset,
1320             dsl_dataset_phys(ds)->ds_snapnames_zapobj,
1321             drba->drba_cookie->drc_tosnap, 8, 1, &val);
1322         if (error != ENOENT)
1323                 return (error == 0 ? EEXIST : error);
1324
1325         /*
1326          * Check snapshot limit before receiving. We'll recheck again at the
1327          * end, but might as well abort before receiving if we're already over
1328          * the limit.
1329          *
1330          * Note that we do not check the file system limit with
1331          * dsl_dir_fscount_check because the temporary %clones don't count
1332          * against that limit.
1333          */
1334         error = dsl_fs_ss_limit_check(ds->ds_dir, 1, ZFS_PROP_SNAPSHOT_LIMIT,
1335             NULL, drba->drba_cred);
1336         if (error != 0)
1337                 return (error);
1338
1339         if (fromguid != 0) {
1340                 dsl_dataset_t *snap;
1341                 uint64_t obj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
1342
1343                 /* Find snapshot in this dir that matches fromguid. */
1344                 while (obj != 0) {
1345                         error = dsl_dataset_hold_obj(dp, obj, FTAG,
1346                             &snap);
1347                         if (error != 0)
1348                                 return (SET_ERROR(ENODEV));
1349                         if (snap->ds_dir != ds->ds_dir) {
1350                                 dsl_dataset_rele(snap, FTAG);
1351                                 return (SET_ERROR(ENODEV));
1352                         }
1353                         if (dsl_dataset_phys(snap)->ds_guid == fromguid)
1354                                 break;
1355                         obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
1356                         dsl_dataset_rele(snap, FTAG);
1357                 }
1358                 if (obj == 0)
1359                         return (SET_ERROR(ENODEV));
1360
1361                 if (drba->drba_cookie->drc_force) {
1362                         drba->drba_snapobj = obj;
1363                 } else {
1364                         /*
1365                          * If we are not forcing, there must be no
1366                          * changes since fromsnap.
1367                          */
1368                         if (dsl_dataset_modified_since_snap(ds, snap)) {
1369                                 dsl_dataset_rele(snap, FTAG);
1370                                 return (SET_ERROR(ETXTBSY));
1371                         }
1372                         drba->drba_snapobj = ds->ds_prev->ds_object;
1373                 }
1374
1375                 dsl_dataset_rele(snap, FTAG);
1376         } else {
1377                 /* if full, then must be forced */
1378                 if (!drba->drba_cookie->drc_force)
1379                         return (SET_ERROR(EEXIST));
1380                 /* start from $ORIGIN@$ORIGIN, if supported */
1381                 drba->drba_snapobj = dp->dp_origin_snap != NULL ?
1382                     dp->dp_origin_snap->ds_object : 0;
1383         }
1384
1385         return (0);
1386
1387 }
1388
1389 static int
1390 dmu_recv_begin_check(void *arg, dmu_tx_t *tx)
1391 {
1392         dmu_recv_begin_arg_t *drba = arg;
1393         dsl_pool_t *dp = dmu_tx_pool(tx);
1394         struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1395         uint64_t fromguid = drrb->drr_fromguid;
1396         int flags = drrb->drr_flags;
1397         int error;
1398         uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
1399         dsl_dataset_t *ds;
1400         const char *tofs = drba->drba_cookie->drc_tofs;
1401
1402         /* already checked */
1403         ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
1404         ASSERT(!(featureflags & DMU_BACKUP_FEATURE_RESUMING));
1405
1406         if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
1407             DMU_COMPOUNDSTREAM ||
1408             drrb->drr_type >= DMU_OST_NUMTYPES ||
1409             ((flags & DRR_FLAG_CLONE) && drba->drba_origin == NULL))
1410                 return (SET_ERROR(EINVAL));
1411
1412         /* Verify pool version supports SA if SA_SPILL feature set */
1413         if ((featureflags & DMU_BACKUP_FEATURE_SA_SPILL) &&
1414             spa_version(dp->dp_spa) < SPA_VERSION_SA)
1415                 return (SET_ERROR(ENOTSUP));
1416
1417         if (drba->drba_cookie->drc_resumable &&
1418             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EXTENSIBLE_DATASET))
1419                 return (SET_ERROR(ENOTSUP));
1420
1421         /*
1422          * The receiving code doesn't know how to translate a WRITE_EMBEDDED
1423          * record to a plain WRITE record, so the pool must have the
1424          * EMBEDDED_DATA feature enabled if the stream has WRITE_EMBEDDED
1425          * records.  Same with WRITE_EMBEDDED records that use LZ4 compression.
1426          */
1427         if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA) &&
1428             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA))
1429                 return (SET_ERROR(ENOTSUP));
1430         if ((featureflags & DMU_BACKUP_FEATURE_LZ4) &&
1431             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
1432                 return (SET_ERROR(ENOTSUP));
1433
1434         /*
1435          * The receiving code doesn't know how to translate large blocks
1436          * to smaller ones, so the pool must have the LARGE_BLOCKS
1437          * feature enabled if the stream has LARGE_BLOCKS.
1438          */
1439         if ((featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
1440             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS))
1441                 return (SET_ERROR(ENOTSUP));
1442
1443         error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1444         if (error == 0) {
1445                 /* target fs already exists; recv into temp clone */
1446
1447                 /* Can't recv a clone into an existing fs */
1448                 if (flags & DRR_FLAG_CLONE || drba->drba_origin) {
1449                         dsl_dataset_rele(ds, FTAG);
1450                         return (SET_ERROR(EINVAL));
1451                 }
1452
1453                 error = recv_begin_check_existing_impl(drba, ds, fromguid);
1454                 dsl_dataset_rele(ds, FTAG);
1455         } else if (error == ENOENT) {
1456                 /* target fs does not exist; must be a full backup or clone */
1457                 char buf[ZFS_MAX_DATASET_NAME_LEN];
1458
1459                 /*
1460                  * If it's a non-clone incremental, we are missing the
1461                  * target fs, so fail the recv.
1462                  */
1463                 if (fromguid != 0 && !(flags & DRR_FLAG_CLONE ||
1464                     drba->drba_origin))
1465                         return (SET_ERROR(ENOENT));
1466
1467                 /*
1468                  * If we're receiving a full send as a clone, and it doesn't
1469                  * contain all the necessary free records and freeobject
1470                  * records, reject it.
1471                  */
1472                 if (fromguid == 0 && drba->drba_origin &&
1473                     !(flags & DRR_FLAG_FREERECORDS))
1474                         return (SET_ERROR(EINVAL));
1475
1476                 /* Open the parent of tofs */
1477                 ASSERT3U(strlen(tofs), <, sizeof (buf));
1478                 (void) strlcpy(buf, tofs, strrchr(tofs, '/') - tofs + 1);
1479                 error = dsl_dataset_hold(dp, buf, FTAG, &ds);
1480                 if (error != 0)
1481                         return (error);
1482
1483                 /*
1484                  * Check filesystem and snapshot limits before receiving. We'll
1485                  * recheck snapshot limits again at the end (we create the
1486                  * filesystems and increment those counts during begin_sync).
1487                  */
1488                 error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
1489                     ZFS_PROP_FILESYSTEM_LIMIT, NULL, drba->drba_cred);
1490                 if (error != 0) {
1491                         dsl_dataset_rele(ds, FTAG);
1492                         return (error);
1493                 }
1494
1495                 error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
1496                     ZFS_PROP_SNAPSHOT_LIMIT, NULL, drba->drba_cred);
1497                 if (error != 0) {
1498                         dsl_dataset_rele(ds, FTAG);
1499                         return (error);
1500                 }
1501
1502                 if (drba->drba_origin != NULL) {
1503                         dsl_dataset_t *origin;
1504                         error = dsl_dataset_hold(dp, drba->drba_origin,
1505                             FTAG, &origin);
1506                         if (error != 0) {
1507                                 dsl_dataset_rele(ds, FTAG);
1508                                 return (error);
1509                         }
1510                         if (!origin->ds_is_snapshot) {
1511                                 dsl_dataset_rele(origin, FTAG);
1512                                 dsl_dataset_rele(ds, FTAG);
1513                                 return (SET_ERROR(EINVAL));
1514                         }
1515                         if (dsl_dataset_phys(origin)->ds_guid != fromguid &&
1516                             fromguid != 0) {
1517                                 dsl_dataset_rele(origin, FTAG);
1518                                 dsl_dataset_rele(ds, FTAG);
1519                                 return (SET_ERROR(ENODEV));
1520                         }
1521                         dsl_dataset_rele(origin, FTAG);
1522                 }
1523                 dsl_dataset_rele(ds, FTAG);
1524                 error = 0;
1525         }
1526         return (error);
1527 }
1528
1529 static void
1530 dmu_recv_begin_sync(void *arg, dmu_tx_t *tx)
1531 {
1532         dmu_recv_begin_arg_t *drba = arg;
1533         dsl_pool_t *dp = dmu_tx_pool(tx);
1534         objset_t *mos = dp->dp_meta_objset;
1535         struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1536         const char *tofs = drba->drba_cookie->drc_tofs;
1537         dsl_dataset_t *ds, *newds;
1538         uint64_t dsobj;
1539         int error;
1540         uint64_t crflags = 0;
1541
1542         if (drrb->drr_flags & DRR_FLAG_CI_DATA)
1543                 crflags |= DS_FLAG_CI_DATASET;
1544
1545         error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1546         if (error == 0) {
1547                 /* create temporary clone */
1548                 dsl_dataset_t *snap = NULL;
1549                 if (drba->drba_snapobj != 0) {
1550                         VERIFY0(dsl_dataset_hold_obj(dp,
1551                             drba->drba_snapobj, FTAG, &snap));
1552                 }
1553                 dsobj = dsl_dataset_create_sync(ds->ds_dir, recv_clone_name,
1554                     snap, crflags, drba->drba_cred, tx);
1555                 if (drba->drba_snapobj != 0)
1556                         dsl_dataset_rele(snap, FTAG);
1557                 dsl_dataset_rele(ds, FTAG);
1558         } else {
1559                 dsl_dir_t *dd;
1560                 const char *tail;
1561                 dsl_dataset_t *origin = NULL;
1562
1563                 VERIFY0(dsl_dir_hold(dp, tofs, FTAG, &dd, &tail));
1564
1565                 if (drba->drba_origin != NULL) {
1566                         VERIFY0(dsl_dataset_hold(dp, drba->drba_origin,
1567                             FTAG, &origin));
1568                 }
1569
1570                 /* Create new dataset. */
1571                 dsobj = dsl_dataset_create_sync(dd,
1572                     strrchr(tofs, '/') + 1,
1573                     origin, crflags, drba->drba_cred, tx);
1574                 if (origin != NULL)
1575                         dsl_dataset_rele(origin, FTAG);
1576                 dsl_dir_rele(dd, FTAG);
1577                 drba->drba_cookie->drc_newfs = B_TRUE;
1578         }
1579         VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &newds));
1580
1581         if (drba->drba_cookie->drc_resumable) {
1582                 dsl_dataset_zapify(newds, tx);
1583                 if (drrb->drr_fromguid != 0) {
1584                         VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_FROMGUID,
1585                             8, 1, &drrb->drr_fromguid, tx));
1586                 }
1587                 VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TOGUID,
1588                     8, 1, &drrb->drr_toguid, tx));
1589                 VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TONAME,
1590                     1, strlen(drrb->drr_toname) + 1, drrb->drr_toname, tx));
1591                 uint64_t one = 1;
1592                 uint64_t zero = 0;
1593                 VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OBJECT,
1594                     8, 1, &one, tx));
1595                 VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OFFSET,
1596                     8, 1, &zero, tx));
1597                 VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_BYTES,
1598                     8, 1, &zero, tx));
1599                 if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1600                     DMU_BACKUP_FEATURE_LARGE_BLOCKS) {
1601                         VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_LARGEBLOCK,
1602                             8, 1, &one, tx));
1603                 }
1604                 if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1605                     DMU_BACKUP_FEATURE_EMBED_DATA) {
1606                         VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_EMBEDOK,
1607                             8, 1, &one, tx));
1608                 }
1609                 if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
1610                     DMU_BACKUP_FEATURE_COMPRESSED) {
1611                         VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_COMPRESSOK,
1612                             8, 1, &one, tx));
1613                 }
1614         }
1615
1616         dmu_buf_will_dirty(newds->ds_dbuf, tx);
1617         dsl_dataset_phys(newds)->ds_flags |= DS_FLAG_INCONSISTENT;
1618
1619         /*
1620          * If we actually created a non-clone, we need to create the
1621          * objset in our new dataset.
1622          */
1623         rrw_enter(&newds->ds_bp_rwlock, RW_READER, FTAG);
1624         if (BP_IS_HOLE(dsl_dataset_get_blkptr(newds))) {
1625                 (void) dmu_objset_create_impl(dp->dp_spa,
1626                     newds, dsl_dataset_get_blkptr(newds), drrb->drr_type, tx);
1627         }
1628         rrw_exit(&newds->ds_bp_rwlock, FTAG);
1629
1630         drba->drba_cookie->drc_ds = newds;
1631
1632         spa_history_log_internal_ds(newds, "receive", tx, "");
1633 }
1634
1635 static int
1636 dmu_recv_resume_begin_check(void *arg, dmu_tx_t *tx)
1637 {
1638         dmu_recv_begin_arg_t *drba = arg;
1639         dsl_pool_t *dp = dmu_tx_pool(tx);
1640         struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
1641         int error;
1642         uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
1643         dsl_dataset_t *ds;
1644         const char *tofs = drba->drba_cookie->drc_tofs;
1645
1646         /* already checked */
1647         ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
1648         ASSERT(featureflags & DMU_BACKUP_FEATURE_RESUMING);
1649
1650         if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
1651             DMU_COMPOUNDSTREAM ||
1652             drrb->drr_type >= DMU_OST_NUMTYPES)
1653                 return (SET_ERROR(EINVAL));
1654
1655         /* Verify pool version supports SA if SA_SPILL feature set */
1656         if ((featureflags & DMU_BACKUP_FEATURE_SA_SPILL) &&
1657             spa_version(dp->dp_spa) < SPA_VERSION_SA)
1658                 return (SET_ERROR(ENOTSUP));
1659
1660         /*
1661          * The receiving code doesn't know how to translate a WRITE_EMBEDDED
1662          * record to a plain WRITE record, so the pool must have the
1663          * EMBEDDED_DATA feature enabled if the stream has WRITE_EMBEDDED
1664          * records.  Same with WRITE_EMBEDDED records that use LZ4 compression.
1665          */
1666         if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA) &&
1667             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA))
1668                 return (SET_ERROR(ENOTSUP));
1669         if ((featureflags & DMU_BACKUP_FEATURE_LZ4) &&
1670             !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
1671                 return (SET_ERROR(ENOTSUP));
1672
1673         /* 6 extra bytes for /%recv */
1674         char recvname[ZFS_MAX_DATASET_NAME_LEN + 6];
1675
1676         (void) snprintf(recvname, sizeof (recvname), "%s/%s",
1677             tofs, recv_clone_name);
1678
1679         if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
1680                 /* %recv does not exist; continue in tofs */
1681                 error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
1682                 if (error != 0)
1683                         return (error);
1684         }
1685
1686         /* check that ds is marked inconsistent */
1687         if (!DS_IS_INCONSISTENT(ds)) {
1688                 dsl_dataset_rele(ds, FTAG);
1689                 return (SET_ERROR(EINVAL));
1690         }
1691
1692         /* check that there is resuming data, and that the toguid matches */
1693         if (!dsl_dataset_is_zapified(ds)) {
1694                 dsl_dataset_rele(ds, FTAG);
1695                 return (SET_ERROR(EINVAL));
1696         }
1697         uint64_t val;
1698         error = zap_lookup(dp->dp_meta_objset, ds->ds_object,
1699             DS_FIELD_RESUME_TOGUID, sizeof (val), 1, &val);
1700         if (error != 0 || drrb->drr_toguid != val) {
1701                 dsl_dataset_rele(ds, FTAG);
1702                 return (SET_ERROR(EINVAL));
1703         }
1704
1705         /*
1706          * Check if the receive is still running.  If so, it will be owned.
1707          * Note that nothing else can own the dataset (e.g. after the receive
1708          * fails) because it will be marked inconsistent.
1709          */
1710         if (dsl_dataset_has_owner(ds)) {
1711                 dsl_dataset_rele(ds, FTAG);
1712                 return (SET_ERROR(EBUSY));
1713         }
1714
1715         /* There should not be any snapshots of this fs yet. */
1716         if (ds->ds_prev != NULL && ds->ds_prev->ds_dir == ds->ds_dir) {
1717                 dsl_dataset_rele(ds, FTAG);
1718                 return (SET_ERROR(EINVAL));
1719         }
1720
1721         /*
1722          * Note: resume point will be checked when we process the first WRITE
1723          * record.
1724          */
1725
1726         /* check that the origin matches */
1727         val = 0;
1728         (void) zap_lookup(dp->dp_meta_objset, ds->ds_object,
1729             DS_FIELD_RESUME_FROMGUID, sizeof (val), 1, &val);
1730         if (drrb->drr_fromguid != val) {
1731                 dsl_dataset_rele(ds, FTAG);
1732                 return (SET_ERROR(EINVAL));
1733         }
1734
1735         dsl_dataset_rele(ds, FTAG);
1736         return (0);
1737 }
1738
1739 static void
1740 dmu_recv_resume_begin_sync(void *arg, dmu_tx_t *tx)
1741 {
1742         dmu_recv_begin_arg_t *drba = arg;
1743         dsl_pool_t *dp = dmu_tx_pool(tx);
1744         const char *tofs = drba->drba_cookie->drc_tofs;
1745         dsl_dataset_t *ds;
1746         uint64_t dsobj;
1747         /* 6 extra bytes for /%recv */
1748         char recvname[ZFS_MAX_DATASET_NAME_LEN + 6];
1749
1750         (void) snprintf(recvname, sizeof (recvname), "%s/%s",
1751             tofs, recv_clone_name);
1752
1753         if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
1754                 /* %recv does not exist; continue in tofs */
1755                 VERIFY0(dsl_dataset_hold(dp, tofs, FTAG, &ds));
1756                 drba->drba_cookie->drc_newfs = B_TRUE;
1757         }
1758
1759         /* clear the inconsistent flag so that we can own it */
1760         ASSERT(DS_IS_INCONSISTENT(ds));
1761         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1762         dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
1763         dsobj = ds->ds_object;
1764         dsl_dataset_rele(ds, FTAG);
1765
1766         VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &ds));
1767
1768         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1769         dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
1770
1771         rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
1772         ASSERT(!BP_IS_HOLE(dsl_dataset_get_blkptr(ds)));
1773         rrw_exit(&ds->ds_bp_rwlock, FTAG);
1774
1775         drba->drba_cookie->drc_ds = ds;
1776
1777         spa_history_log_internal_ds(ds, "resume receive", tx, "");
1778 }
1779
1780 /*
1781  * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
1782  * succeeds; otherwise we will leak the holds on the datasets.
1783  */
1784 int
1785 dmu_recv_begin(char *tofs, char *tosnap, dmu_replay_record_t *drr_begin,
1786     boolean_t force, boolean_t resumable, char *origin, dmu_recv_cookie_t *drc)
1787 {
1788         dmu_recv_begin_arg_t drba = { 0 };
1789
1790         bzero(drc, sizeof (dmu_recv_cookie_t));
1791         drc->drc_drr_begin = drr_begin;
1792         drc->drc_drrb = &drr_begin->drr_u.drr_begin;
1793         drc->drc_tosnap = tosnap;
1794         drc->drc_tofs = tofs;
1795         drc->drc_force = force;
1796         drc->drc_resumable = resumable;
1797         drc->drc_cred = CRED();
1798
1799         if (drc->drc_drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC)) {
1800                 drc->drc_byteswap = B_TRUE;
1801                 (void) fletcher_4_incremental_byteswap(drr_begin,
1802                     sizeof (dmu_replay_record_t), &drc->drc_cksum);
1803                 byteswap_record(drr_begin);
1804         } else if (drc->drc_drrb->drr_magic == DMU_BACKUP_MAGIC) {
1805                 (void) fletcher_4_incremental_native(drr_begin,
1806                     sizeof (dmu_replay_record_t), &drc->drc_cksum);
1807         } else {
1808                 return (SET_ERROR(EINVAL));
1809         }
1810
1811         drba.drba_origin = origin;
1812         drba.drba_cookie = drc;
1813         drba.drba_cred = CRED();
1814
1815         if (DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo) &
1816             DMU_BACKUP_FEATURE_RESUMING) {
1817                 return (dsl_sync_task(tofs,
1818                     dmu_recv_resume_begin_check, dmu_recv_resume_begin_sync,
1819                     &drba, 5, ZFS_SPACE_CHECK_NORMAL));
1820         } else  {
1821                 return (dsl_sync_task(tofs,
1822                     dmu_recv_begin_check, dmu_recv_begin_sync,
1823                     &drba, 5, ZFS_SPACE_CHECK_NORMAL));
1824         }
1825 }
1826
1827 struct receive_record_arg {
1828         dmu_replay_record_t header;
1829         void *payload; /* Pointer to a buffer containing the payload */
1830         /*
1831          * If the record is a write, pointer to the arc_buf_t containing the
1832          * payload.
1833          */
1834         arc_buf_t *write_buf;
1835         int payload_size;
1836         uint64_t bytes_read; /* bytes read from stream when record created */
1837         boolean_t eos_marker; /* Marks the end of the stream */
1838         bqueue_node_t node;
1839 };
1840
1841 struct receive_writer_arg {
1842         objset_t *os;
1843         boolean_t byteswap;
1844         bqueue_t q;
1845
1846         /*
1847          * These three args are used to signal to the main thread that we're
1848          * done.
1849          */
1850         kmutex_t mutex;
1851         kcondvar_t cv;
1852         boolean_t done;
1853
1854         int err;
1855         /* A map from guid to dataset to help handle dedup'd streams. */
1856         avl_tree_t *guid_to_ds_map;
1857         boolean_t resumable;
1858         uint64_t last_object, last_offset;
1859         uint64_t bytes_read; /* bytes read when current record created */
1860 };
1861
1862 struct objlist {
1863         list_t list; /* List of struct receive_objnode. */
1864         /*
1865          * Last object looked up. Used to assert that objects are being looked
1866          * up in ascending order.
1867          */
1868         uint64_t last_lookup;
1869 };
1870
1871 struct receive_objnode {
1872         list_node_t node;
1873         uint64_t object;
1874 };
1875
1876 struct receive_arg {
1877         objset_t *os;
1878         kthread_t *td;
1879         struct file *fp;
1880         uint64_t voff; /* The current offset in the stream */
1881         uint64_t bytes_read;
1882         /*
1883          * A record that has had its payload read in, but hasn't yet been handed
1884          * off to the worker thread.
1885          */
1886         struct receive_record_arg *rrd;
1887         /* A record that has had its header read in, but not its payload. */
1888         struct receive_record_arg *next_rrd;
1889         zio_cksum_t cksum;
1890         zio_cksum_t prev_cksum;
1891         int err;
1892         boolean_t byteswap;
1893         /* Sorted list of objects not to issue prefetches for. */
1894         struct objlist ignore_objlist;
1895 };
1896
1897 typedef struct guid_map_entry {
1898         uint64_t        guid;
1899         dsl_dataset_t   *gme_ds;
1900         avl_node_t      avlnode;
1901 } guid_map_entry_t;
1902
1903 static int
1904 guid_compare(const void *arg1, const void *arg2)
1905 {
1906         const guid_map_entry_t *gmep1 = arg1;
1907         const guid_map_entry_t *gmep2 = arg2;
1908
1909         if (gmep1->guid < gmep2->guid)
1910                 return (-1);
1911         else if (gmep1->guid > gmep2->guid)
1912                 return (1);
1913         return (0);
1914 }
1915
1916 static void
1917 free_guid_map_onexit(void *arg)
1918 {
1919         avl_tree_t *ca = arg;
1920         void *cookie = NULL;
1921         guid_map_entry_t *gmep;
1922
1923         while ((gmep = avl_destroy_nodes(ca, &cookie)) != NULL) {
1924                 dsl_dataset_long_rele(gmep->gme_ds, gmep);
1925                 dsl_dataset_rele(gmep->gme_ds, gmep);
1926                 kmem_free(gmep, sizeof (guid_map_entry_t));
1927         }
1928         avl_destroy(ca);
1929         kmem_free(ca, sizeof (avl_tree_t));
1930 }
1931
1932 static int
1933 restore_bytes(struct receive_arg *ra, void *buf, int len, off_t off, ssize_t *resid)
1934 {
1935         struct uio auio;
1936         struct iovec aiov;
1937         int error;
1938
1939         aiov.iov_base = buf;
1940         aiov.iov_len = len;
1941         auio.uio_iov = &aiov;
1942         auio.uio_iovcnt = 1;
1943         auio.uio_resid = len;
1944         auio.uio_segflg = UIO_SYSSPACE;
1945         auio.uio_rw = UIO_READ;
1946         auio.uio_offset = off;
1947         auio.uio_td = ra->td;
1948 #ifdef _KERNEL
1949         error = fo_read(ra->fp, &auio, ra->td->td_ucred, FOF_OFFSET, ra->td);
1950 #else
1951         fprintf(stderr, "%s: returning EOPNOTSUPP\n", __func__);
1952         error = EOPNOTSUPP;
1953 #endif
1954         *resid = auio.uio_resid;
1955         return (error);
1956 }
1957
1958 static int
1959 receive_read(struct receive_arg *ra, int len, void *buf)
1960 {
1961         int done = 0;
1962
1963         /*
1964          * The code doesn't rely on this (lengths being multiples of 8).  See
1965          * comment in dump_bytes.
1966          */
1967         ASSERT0(len % 8);
1968
1969         while (done < len) {
1970                 ssize_t resid;
1971
1972                 ra->err = restore_bytes(ra, buf + done,
1973                     len - done, ra->voff, &resid);
1974
1975                 if (resid == len - done) {
1976                         /*
1977                          * Note: ECKSUM indicates that the receive
1978                          * was interrupted and can potentially be resumed.
1979                          */
1980                         ra->err = SET_ERROR(ECKSUM);
1981                 }
1982                 ra->voff += len - done - resid;
1983                 done = len - resid;
1984                 if (ra->err != 0)
1985                         return (ra->err);
1986         }
1987
1988         ra->bytes_read += len;
1989
1990         ASSERT3U(done, ==, len);
1991         return (0);
1992 }
1993
1994 static void
1995 byteswap_record(dmu_replay_record_t *drr)
1996 {
1997 #define DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
1998 #define DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
1999         drr->drr_type = BSWAP_32(drr->drr_type);
2000         drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
2001
2002         switch (drr->drr_type) {
2003         case DRR_BEGIN:
2004                 DO64(drr_begin.drr_magic);
2005                 DO64(drr_begin.drr_versioninfo);
2006                 DO64(drr_begin.drr_creation_time);
2007                 DO32(drr_begin.drr_type);
2008                 DO32(drr_begin.drr_flags);
2009                 DO64(drr_begin.drr_toguid);
2010                 DO64(drr_begin.drr_fromguid);
2011                 break;
2012         case DRR_OBJECT:
2013                 DO64(drr_object.drr_object);
2014                 DO32(drr_object.drr_type);
2015                 DO32(drr_object.drr_bonustype);
2016                 DO32(drr_object.drr_blksz);
2017                 DO32(drr_object.drr_bonuslen);
2018                 DO64(drr_object.drr_toguid);
2019                 break;
2020         case DRR_FREEOBJECTS:
2021                 DO64(drr_freeobjects.drr_firstobj);
2022                 DO64(drr_freeobjects.drr_numobjs);
2023                 DO64(drr_freeobjects.drr_toguid);
2024                 break;
2025         case DRR_WRITE:
2026                 DO64(drr_write.drr_object);
2027                 DO32(drr_write.drr_type);
2028                 DO64(drr_write.drr_offset);
2029                 DO64(drr_write.drr_logical_size);
2030                 DO64(drr_write.drr_toguid);
2031                 ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write.drr_key.ddk_cksum);
2032                 DO64(drr_write.drr_key.ddk_prop);
2033                 DO64(drr_write.drr_compressed_size);
2034                 break;
2035         case DRR_WRITE_BYREF:
2036                 DO64(drr_write_byref.drr_object);
2037                 DO64(drr_write_byref.drr_offset);
2038                 DO64(drr_write_byref.drr_length);
2039                 DO64(drr_write_byref.drr_toguid);
2040                 DO64(drr_write_byref.drr_refguid);
2041                 DO64(drr_write_byref.drr_refobject);
2042                 DO64(drr_write_byref.drr_refoffset);
2043                 ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write_byref.
2044                     drr_key.ddk_cksum);
2045                 DO64(drr_write_byref.drr_key.ddk_prop);
2046                 break;
2047         case DRR_WRITE_EMBEDDED:
2048                 DO64(drr_write_embedded.drr_object);
2049                 DO64(drr_write_embedded.drr_offset);
2050                 DO64(drr_write_embedded.drr_length);
2051                 DO64(drr_write_embedded.drr_toguid);
2052                 DO32(drr_write_embedded.drr_lsize);
2053                 DO32(drr_write_embedded.drr_psize);
2054                 break;
2055         case DRR_FREE:
2056                 DO64(drr_free.drr_object);
2057                 DO64(drr_free.drr_offset);
2058                 DO64(drr_free.drr_length);
2059                 DO64(drr_free.drr_toguid);
2060                 break;
2061         case DRR_SPILL:
2062                 DO64(drr_spill.drr_object);
2063                 DO64(drr_spill.drr_length);
2064                 DO64(drr_spill.drr_toguid);
2065                 break;
2066         case DRR_END:
2067                 DO64(drr_end.drr_toguid);
2068                 ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_end.drr_checksum);
2069                 break;
2070         }
2071
2072         if (drr->drr_type != DRR_BEGIN) {
2073                 ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_checksum.drr_checksum);
2074         }
2075
2076 #undef DO64
2077 #undef DO32
2078 }
2079
2080 static inline uint8_t
2081 deduce_nblkptr(dmu_object_type_t bonus_type, uint64_t bonus_size)
2082 {
2083         if (bonus_type == DMU_OT_SA) {
2084                 return (1);
2085         } else {
2086                 return (1 +
2087                     ((DN_MAX_BONUSLEN - bonus_size) >> SPA_BLKPTRSHIFT));
2088         }
2089 }
2090
2091 static void
2092 save_resume_state(struct receive_writer_arg *rwa,
2093     uint64_t object, uint64_t offset, dmu_tx_t *tx)
2094 {
2095         int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
2096
2097         if (!rwa->resumable)
2098                 return;
2099
2100         /*
2101          * We use ds_resume_bytes[] != 0 to indicate that we need to
2102          * update this on disk, so it must not be 0.
2103          */
2104         ASSERT(rwa->bytes_read != 0);
2105
2106         /*
2107          * We only resume from write records, which have a valid
2108          * (non-meta-dnode) object number.
2109          */
2110         ASSERT(object != 0);
2111
2112         /*
2113          * For resuming to work correctly, we must receive records in order,
2114          * sorted by object,offset.  This is checked by the callers, but
2115          * assert it here for good measure.
2116          */
2117         ASSERT3U(object, >=, rwa->os->os_dsl_dataset->ds_resume_object[txgoff]);
2118         ASSERT(object != rwa->os->os_dsl_dataset->ds_resume_object[txgoff] ||
2119             offset >= rwa->os->os_dsl_dataset->ds_resume_offset[txgoff]);
2120         ASSERT3U(rwa->bytes_read, >=,
2121             rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff]);
2122
2123         rwa->os->os_dsl_dataset->ds_resume_object[txgoff] = object;
2124         rwa->os->os_dsl_dataset->ds_resume_offset[txgoff] = offset;
2125         rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff] = rwa->bytes_read;
2126 }
2127
2128 static int
2129 receive_object(struct receive_writer_arg *rwa, struct drr_object *drro,
2130     void *data)
2131 {
2132         dmu_object_info_t doi;
2133         dmu_tx_t *tx;
2134         uint64_t object;
2135         int err;
2136
2137         if (drro->drr_type == DMU_OT_NONE ||
2138             !DMU_OT_IS_VALID(drro->drr_type) ||
2139             !DMU_OT_IS_VALID(drro->drr_bonustype) ||
2140             drro->drr_checksumtype >= ZIO_CHECKSUM_FUNCTIONS ||
2141             drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
2142             P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
2143             drro->drr_blksz < SPA_MINBLOCKSIZE ||
2144             drro->drr_blksz > spa_maxblocksize(dmu_objset_spa(rwa->os)) ||
2145             drro->drr_bonuslen > DN_MAX_BONUSLEN) {
2146                 return (SET_ERROR(EINVAL));
2147         }
2148
2149         err = dmu_object_info(rwa->os, drro->drr_object, &doi);
2150
2151         if (err != 0 && err != ENOENT)
2152                 return (SET_ERROR(EINVAL));
2153         object = err == 0 ? drro->drr_object : DMU_NEW_OBJECT;
2154
2155         /*
2156          * If we are losing blkptrs or changing the block size this must
2157          * be a new file instance.  We must clear out the previous file
2158          * contents before we can change this type of metadata in the dnode.
2159          */
2160         if (err == 0) {
2161                 int nblkptr;
2162
2163                 nblkptr = deduce_nblkptr(drro->drr_bonustype,
2164                     drro->drr_bonuslen);
2165
2166                 if (drro->drr_blksz != doi.doi_data_block_size ||
2167                     nblkptr < doi.doi_nblkptr) {
2168                         err = dmu_free_long_range(rwa->os, drro->drr_object,
2169                             0, DMU_OBJECT_END);
2170                         if (err != 0)
2171                                 return (SET_ERROR(EINVAL));
2172                 }
2173         }
2174
2175         tx = dmu_tx_create(rwa->os);
2176         dmu_tx_hold_bonus(tx, object);
2177         err = dmu_tx_assign(tx, TXG_WAIT);
2178         if (err != 0) {
2179                 dmu_tx_abort(tx);
2180                 return (err);
2181         }
2182
2183         if (object == DMU_NEW_OBJECT) {
2184                 /* currently free, want to be allocated */
2185                 err = dmu_object_claim(rwa->os, drro->drr_object,
2186                     drro->drr_type, drro->drr_blksz,
2187                     drro->drr_bonustype, drro->drr_bonuslen, tx);
2188         } else if (drro->drr_type != doi.doi_type ||
2189             drro->drr_blksz != doi.doi_data_block_size ||
2190             drro->drr_bonustype != doi.doi_bonus_type ||
2191             drro->drr_bonuslen != doi.doi_bonus_size) {
2192                 /* currently allocated, but with different properties */
2193                 err = dmu_object_reclaim(rwa->os, drro->drr_object,
2194                     drro->drr_type, drro->drr_blksz,
2195                     drro->drr_bonustype, drro->drr_bonuslen, tx);
2196         }
2197         if (err != 0) {
2198                 dmu_tx_commit(tx);
2199                 return (SET_ERROR(EINVAL));
2200         }
2201
2202         dmu_object_set_checksum(rwa->os, drro->drr_object,
2203             drro->drr_checksumtype, tx);
2204         dmu_object_set_compress(rwa->os, drro->drr_object,
2205             drro->drr_compress, tx);
2206
2207         if (data != NULL) {
2208                 dmu_buf_t *db;
2209
2210                 VERIFY0(dmu_bonus_hold(rwa->os, drro->drr_object, FTAG, &db));
2211                 dmu_buf_will_dirty(db, tx);
2212
2213                 ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
2214                 bcopy(data, db->db_data, drro->drr_bonuslen);
2215                 if (rwa->byteswap) {
2216                         dmu_object_byteswap_t byteswap =
2217                             DMU_OT_BYTESWAP(drro->drr_bonustype);
2218                         dmu_ot_byteswap[byteswap].ob_func(db->db_data,
2219                             drro->drr_bonuslen);
2220                 }
2221                 dmu_buf_rele(db, FTAG);
2222         }
2223         dmu_tx_commit(tx);
2224
2225         return (0);
2226 }
2227
2228 /* ARGSUSED */
2229 static int
2230 receive_freeobjects(struct receive_writer_arg *rwa,
2231     struct drr_freeobjects *drrfo)
2232 {
2233         uint64_t obj;
2234         int next_err = 0;
2235
2236         if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
2237                 return (SET_ERROR(EINVAL));
2238
2239         for (obj = drrfo->drr_firstobj;
2240             obj < drrfo->drr_firstobj + drrfo->drr_numobjs && next_err == 0;
2241             next_err = dmu_object_next(rwa->os, &obj, FALSE, 0)) {
2242                 int err;
2243
2244                 if (dmu_object_info(rwa->os, obj, NULL) != 0)
2245                         continue;
2246
2247                 err = dmu_free_long_object(rwa->os, obj);
2248                 if (err != 0)
2249                         return (err);
2250         }
2251         if (next_err != ESRCH)
2252                 return (next_err);
2253         return (0);
2254 }
2255
2256 static int
2257 receive_write(struct receive_writer_arg *rwa, struct drr_write *drrw,
2258     arc_buf_t *abuf)
2259 {
2260         dmu_tx_t *tx;
2261         int err;
2262
2263         if (drrw->drr_offset + drrw->drr_logical_size < drrw->drr_offset ||
2264             !DMU_OT_IS_VALID(drrw->drr_type))
2265                 return (SET_ERROR(EINVAL));
2266
2267         /*
2268          * For resuming to work, records must be in increasing order
2269          * by (object, offset).
2270          */
2271         if (drrw->drr_object < rwa->last_object ||
2272             (drrw->drr_object == rwa->last_object &&
2273             drrw->drr_offset < rwa->last_offset)) {
2274                 return (SET_ERROR(EINVAL));
2275         }
2276         rwa->last_object = drrw->drr_object;
2277         rwa->last_offset = drrw->drr_offset;
2278
2279         if (dmu_object_info(rwa->os, drrw->drr_object, NULL) != 0)
2280                 return (SET_ERROR(EINVAL));
2281
2282         tx = dmu_tx_create(rwa->os);
2283
2284         dmu_tx_hold_write(tx, drrw->drr_object,
2285             drrw->drr_offset, drrw->drr_logical_size);
2286         err = dmu_tx_assign(tx, TXG_WAIT);
2287         if (err != 0) {
2288                 dmu_tx_abort(tx);
2289                 return (err);
2290         }
2291         if (rwa->byteswap) {
2292                 dmu_object_byteswap_t byteswap =
2293                     DMU_OT_BYTESWAP(drrw->drr_type);
2294                 dmu_ot_byteswap[byteswap].ob_func(abuf->b_data,
2295                     DRR_WRITE_PAYLOAD_SIZE(drrw));
2296         }
2297
2298         /* use the bonus buf to look up the dnode in dmu_assign_arcbuf */
2299         dmu_buf_t *bonus;
2300         if (dmu_bonus_hold(rwa->os, drrw->drr_object, FTAG, &bonus) != 0)
2301                 return (SET_ERROR(EINVAL));
2302         dmu_assign_arcbuf(bonus, drrw->drr_offset, abuf, tx);
2303
2304         /*
2305          * Note: If the receive fails, we want the resume stream to start
2306          * with the same record that we last successfully received (as opposed
2307          * to the next record), so that we can verify that we are
2308          * resuming from the correct location.
2309          */
2310         save_resume_state(rwa, drrw->drr_object, drrw->drr_offset, tx);
2311         dmu_tx_commit(tx);
2312         dmu_buf_rele(bonus, FTAG);
2313
2314         return (0);
2315 }
2316
2317 /*
2318  * Handle a DRR_WRITE_BYREF record.  This record is used in dedup'ed
2319  * streams to refer to a copy of the data that is already on the
2320  * system because it came in earlier in the stream.  This function
2321  * finds the earlier copy of the data, and uses that copy instead of
2322  * data from the stream to fulfill this write.
2323  */
2324 static int
2325 receive_write_byref(struct receive_writer_arg *rwa,
2326     struct drr_write_byref *drrwbr)
2327 {
2328         dmu_tx_t *tx;
2329         int err;
2330         guid_map_entry_t gmesrch;
2331         guid_map_entry_t *gmep;
2332         avl_index_t where;
2333         objset_t *ref_os = NULL;
2334         dmu_buf_t *dbp;
2335
2336         if (drrwbr->drr_offset + drrwbr->drr_length < drrwbr->drr_offset)
2337                 return (SET_ERROR(EINVAL));
2338
2339         /*
2340          * If the GUID of the referenced dataset is different from the
2341          * GUID of the target dataset, find the referenced dataset.
2342          */
2343         if (drrwbr->drr_toguid != drrwbr->drr_refguid) {
2344                 gmesrch.guid = drrwbr->drr_refguid;
2345                 if ((gmep = avl_find(rwa->guid_to_ds_map, &gmesrch,
2346                     &where)) == NULL) {
2347                         return (SET_ERROR(EINVAL));
2348                 }
2349                 if (dmu_objset_from_ds(gmep->gme_ds, &ref_os))
2350                         return (SET_ERROR(EINVAL));
2351         } else {
2352                 ref_os = rwa->os;
2353         }
2354
2355         err = dmu_buf_hold(ref_os, drrwbr->drr_refobject,
2356             drrwbr->drr_refoffset, FTAG, &dbp, DMU_READ_PREFETCH);
2357         if (err != 0)
2358                 return (err);
2359
2360         tx = dmu_tx_create(rwa->os);
2361
2362         dmu_tx_hold_write(tx, drrwbr->drr_object,
2363             drrwbr->drr_offset, drrwbr->drr_length);
2364         err = dmu_tx_assign(tx, TXG_WAIT);
2365         if (err != 0) {
2366                 dmu_tx_abort(tx);
2367                 return (err);
2368         }
2369         dmu_write(rwa->os, drrwbr->drr_object,
2370             drrwbr->drr_offset, drrwbr->drr_length, dbp->db_data, tx);
2371         dmu_buf_rele(dbp, FTAG);
2372
2373         /* See comment in restore_write. */
2374         save_resume_state(rwa, drrwbr->drr_object, drrwbr->drr_offset, tx);
2375         dmu_tx_commit(tx);
2376         return (0);
2377 }
2378
2379 static int
2380 receive_write_embedded(struct receive_writer_arg *rwa,
2381     struct drr_write_embedded *drrwe, void *data)
2382 {
2383         dmu_tx_t *tx;
2384         int err;
2385
2386         if (drrwe->drr_offset + drrwe->drr_length < drrwe->drr_offset)
2387                 return (EINVAL);
2388
2389         if (drrwe->drr_psize > BPE_PAYLOAD_SIZE)
2390                 return (EINVAL);
2391
2392         if (drrwe->drr_etype >= NUM_BP_EMBEDDED_TYPES)
2393                 return (EINVAL);
2394         if (drrwe->drr_compression >= ZIO_COMPRESS_FUNCTIONS)
2395                 return (EINVAL);
2396
2397         tx = dmu_tx_create(rwa->os);
2398
2399         dmu_tx_hold_write(tx, drrwe->drr_object,
2400             drrwe->drr_offset, drrwe->drr_length);
2401         err = dmu_tx_assign(tx, TXG_WAIT);
2402         if (err != 0) {
2403                 dmu_tx_abort(tx);
2404                 return (err);
2405         }
2406
2407         dmu_write_embedded(rwa->os, drrwe->drr_object,
2408             drrwe->drr_offset, data, drrwe->drr_etype,
2409             drrwe->drr_compression, drrwe->drr_lsize, drrwe->drr_psize,
2410             rwa->byteswap ^ ZFS_HOST_BYTEORDER, tx);
2411
2412         /* See comment in restore_write. */
2413         save_resume_state(rwa, drrwe->drr_object, drrwe->drr_offset, tx);
2414         dmu_tx_commit(tx);
2415         return (0);
2416 }
2417
2418 static int
2419 receive_spill(struct receive_writer_arg *rwa, struct drr_spill *drrs,
2420     void *data)
2421 {
2422         dmu_tx_t *tx;
2423         dmu_buf_t *db, *db_spill;
2424         int err;
2425
2426         if (drrs->drr_length < SPA_MINBLOCKSIZE ||
2427             drrs->drr_length > spa_maxblocksize(dmu_objset_spa(rwa->os)))
2428                 return (SET_ERROR(EINVAL));
2429
2430         if (dmu_object_info(rwa->os, drrs->drr_object, NULL) != 0)
2431                 return (SET_ERROR(EINVAL));
2432
2433         VERIFY0(dmu_bonus_hold(rwa->os, drrs->drr_object, FTAG, &db));
2434         if ((err = dmu_spill_hold_by_bonus(db, FTAG, &db_spill)) != 0) {
2435                 dmu_buf_rele(db, FTAG);
2436                 return (err);
2437         }
2438
2439         tx = dmu_tx_create(rwa->os);
2440
2441         dmu_tx_hold_spill(tx, db->db_object);
2442
2443         err = dmu_tx_assign(tx, TXG_WAIT);
2444         if (err != 0) {
2445                 dmu_buf_rele(db, FTAG);
2446                 dmu_buf_rele(db_spill, FTAG);
2447                 dmu_tx_abort(tx);
2448                 return (err);
2449         }
2450         dmu_buf_will_dirty(db_spill, tx);
2451
2452         if (db_spill->db_size < drrs->drr_length)
2453                 VERIFY(0 == dbuf_spill_set_blksz(db_spill,
2454                     drrs->drr_length, tx));
2455         bcopy(data, db_spill->db_data, drrs->drr_length);
2456
2457         dmu_buf_rele(db, FTAG);
2458         dmu_buf_rele(db_spill, FTAG);
2459
2460         dmu_tx_commit(tx);
2461         return (0);
2462 }
2463
2464 /* ARGSUSED */
2465 static int
2466 receive_free(struct receive_writer_arg *rwa, struct drr_free *drrf)
2467 {
2468         int err;
2469
2470         if (drrf->drr_length != -1ULL &&
2471             drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
2472                 return (SET_ERROR(EINVAL));
2473
2474         if (dmu_object_info(rwa->os, drrf->drr_object, NULL) != 0)
2475                 return (SET_ERROR(EINVAL));
2476
2477         err = dmu_free_long_range(rwa->os, drrf->drr_object,
2478             drrf->drr_offset, drrf->drr_length);
2479
2480         return (err);
2481 }
2482
2483 /* used to destroy the drc_ds on error */
2484 static void
2485 dmu_recv_cleanup_ds(dmu_recv_cookie_t *drc)
2486 {
2487         if (drc->drc_resumable) {
2488                 /* wait for our resume state to be written to disk */
2489                 txg_wait_synced(drc->drc_ds->ds_dir->dd_pool, 0);
2490                 dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
2491         } else {
2492                 char name[ZFS_MAX_DATASET_NAME_LEN];
2493                 dsl_dataset_name(drc->drc_ds, name);
2494                 dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
2495                 (void) dsl_destroy_head(name);
2496         }
2497 }
2498
2499 static void
2500 receive_cksum(struct receive_arg *ra, int len, void *buf)
2501 {
2502         if (ra->byteswap) {
2503                 (void) fletcher_4_incremental_byteswap(buf, len, &ra->cksum);
2504         } else {
2505                 (void) fletcher_4_incremental_native(buf, len, &ra->cksum);
2506         }
2507 }
2508
2509 /*
2510  * Read the payload into a buffer of size len, and update the current record's
2511  * payload field.
2512  * Allocate ra->next_rrd and read the next record's header into
2513  * ra->next_rrd->header.
2514  * Verify checksum of payload and next record.
2515  */
2516 static int
2517 receive_read_payload_and_next_header(struct receive_arg *ra, int len, void *buf)
2518 {
2519         int err;
2520
2521         if (len != 0) {
2522                 ASSERT3U(len, <=, SPA_MAXBLOCKSIZE);
2523                 err = receive_read(ra, len, buf);
2524                 if (err != 0)
2525                         return (err);
2526                 receive_cksum(ra, len, buf);
2527
2528                 /* note: rrd is NULL when reading the begin record's payload */
2529                 if (ra->rrd != NULL) {
2530                         ra->rrd->payload = buf;
2531                         ra->rrd->payload_size = len;
2532                         ra->rrd->bytes_read = ra->bytes_read;
2533                 }
2534         }
2535
2536         ra->prev_cksum = ra->cksum;
2537
2538         ra->next_rrd = kmem_zalloc(sizeof (*ra->next_rrd), KM_SLEEP);
2539         err = receive_read(ra, sizeof (ra->next_rrd->header),
2540             &ra->next_rrd->header);
2541         ra->next_rrd->bytes_read = ra->bytes_read;
2542         if (err != 0) {
2543                 kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2544                 ra->next_rrd = NULL;
2545                 return (err);
2546         }
2547         if (ra->next_rrd->header.drr_type == DRR_BEGIN) {
2548                 kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2549                 ra->next_rrd = NULL;
2550                 return (SET_ERROR(EINVAL));
2551         }
2552
2553         /*
2554          * Note: checksum is of everything up to but not including the
2555          * checksum itself.
2556          */
2557         ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
2558             ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
2559         receive_cksum(ra,
2560             offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
2561             &ra->next_rrd->header);
2562
2563         zio_cksum_t cksum_orig =
2564             ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
2565         zio_cksum_t *cksump =
2566             &ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
2567
2568         if (ra->byteswap)
2569                 byteswap_record(&ra->next_rrd->header);
2570
2571         if ((!ZIO_CHECKSUM_IS_ZERO(cksump)) &&
2572             !ZIO_CHECKSUM_EQUAL(ra->cksum, *cksump)) {
2573                 kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
2574                 ra->next_rrd = NULL;
2575                 return (SET_ERROR(ECKSUM));
2576         }
2577
2578         receive_cksum(ra, sizeof (cksum_orig), &cksum_orig);
2579
2580         return (0);
2581 }
2582
2583 static void
2584 objlist_create(struct objlist *list)
2585 {
2586         list_create(&list->list, sizeof (struct receive_objnode),
2587             offsetof(struct receive_objnode, node));
2588         list->last_lookup = 0;
2589 }
2590
2591 static void
2592 objlist_destroy(struct objlist *list)
2593 {
2594         for (struct receive_objnode *n = list_remove_head(&list->list);
2595             n != NULL; n = list_remove_head(&list->list)) {
2596                 kmem_free(n, sizeof (*n));
2597         }
2598         list_destroy(&list->list);
2599 }
2600
2601 /*
2602  * This function looks through the objlist to see if the specified object number
2603  * is contained in the objlist.  In the process, it will remove all object
2604  * numbers in the list that are smaller than the specified object number.  Thus,
2605  * any lookup of an object number smaller than a previously looked up object
2606  * number will always return false; therefore, all lookups should be done in
2607  * ascending order.
2608  */
2609 static boolean_t
2610 objlist_exists(struct objlist *list, uint64_t object)
2611 {
2612         struct receive_objnode *node = list_head(&list->list);
2613         ASSERT3U(object, >=, list->last_lookup);
2614         list->last_lookup = object;
2615         while (node != NULL && node->object < object) {
2616                 VERIFY3P(node, ==, list_remove_head(&list->list));
2617                 kmem_free(node, sizeof (*node));
2618                 node = list_head(&list->list);
2619         }
2620         return (node != NULL && node->object == object);
2621 }
2622
2623 /*
2624  * The objlist is a list of object numbers stored in ascending order.  However,
2625  * the insertion of new object numbers does not seek out the correct location to
2626  * store a new object number; instead, it appends it to the list for simplicity.
2627  * Thus, any users must take care to only insert new object numbers in ascending
2628  * order.
2629  */
2630 static void
2631 objlist_insert(struct objlist *list, uint64_t object)
2632 {
2633         struct receive_objnode *node = kmem_zalloc(sizeof (*node), KM_SLEEP);
2634         node->object = object;
2635 #ifdef ZFS_DEBUG
2636         struct receive_objnode *last_object = list_tail(&list->list);
2637         uint64_t last_objnum = (last_object != NULL ? last_object->object : 0);
2638         ASSERT3U(node->object, >, last_objnum);
2639 #endif
2640         list_insert_tail(&list->list, node);
2641 }
2642
2643 /*
2644  * Issue the prefetch reads for any necessary indirect blocks.
2645  *
2646  * We use the object ignore list to tell us whether or not to issue prefetches
2647  * for a given object.  We do this for both correctness (in case the blocksize
2648  * of an object has changed) and performance (if the object doesn't exist, don't
2649  * needlessly try to issue prefetches).  We also trim the list as we go through
2650  * the stream to prevent it from growing to an unbounded size.
2651  *
2652  * The object numbers within will always be in sorted order, and any write
2653  * records we see will also be in sorted order, but they're not sorted with
2654  * respect to each other (i.e. we can get several object records before
2655  * receiving each object's write records).  As a result, once we've reached a
2656  * given object number, we can safely remove any reference to lower object
2657  * numbers in the ignore list. In practice, we receive up to 32 object records
2658  * before receiving write records, so the list can have up to 32 nodes in it.
2659  */
2660 /* ARGSUSED */
2661 static void
2662 receive_read_prefetch(struct receive_arg *ra,
2663     uint64_t object, uint64_t offset, uint64_t length)
2664 {
2665         if (!objlist_exists(&ra->ignore_objlist, object)) {
2666                 dmu_prefetch(ra->os, object, 1, offset, length,
2667                     ZIO_PRIORITY_SYNC_READ);
2668         }
2669 }
2670
2671 /*
2672  * Read records off the stream, issuing any necessary prefetches.
2673  */
2674 static int
2675 receive_read_record(struct receive_arg *ra)
2676 {
2677         int err;
2678
2679         switch (ra->rrd->header.drr_type) {
2680         case DRR_OBJECT:
2681         {
2682                 struct drr_object *drro = &ra->rrd->header.drr_u.drr_object;
2683                 uint32_t size = P2ROUNDUP(drro->drr_bonuslen, 8);
2684                 void *buf = kmem_zalloc(size, KM_SLEEP);
2685                 dmu_object_info_t doi;
2686                 err = receive_read_payload_and_next_header(ra, size, buf);
2687                 if (err != 0) {
2688                         kmem_free(buf, size);
2689                         return (err);
2690                 }
2691                 err = dmu_object_info(ra->os, drro->drr_object, &doi);
2692                 /*
2693                  * See receive_read_prefetch for an explanation why we're
2694                  * storing this object in the ignore_obj_list.
2695                  */
2696                 if (err == ENOENT ||
2697                     (err == 0 && doi.doi_data_block_size != drro->drr_blksz)) {
2698                         objlist_insert(&ra->ignore_objlist, drro->drr_object);
2699                         err = 0;
2700                 }
2701                 return (err);
2702         }
2703         case DRR_FREEOBJECTS:
2704         {
2705                 err = receive_read_payload_and_next_header(ra, 0, NULL);
2706                 return (err);
2707         }
2708         case DRR_WRITE:
2709         {
2710                 struct drr_write *drrw = &ra->rrd->header.drr_u.drr_write;
2711                 arc_buf_t *abuf;
2712                 boolean_t is_meta = DMU_OT_IS_METADATA(drrw->drr_type);
2713                 if (DRR_WRITE_COMPRESSED(drrw)) {
2714                         ASSERT3U(drrw->drr_compressed_size, >, 0);
2715                         ASSERT3U(drrw->drr_logical_size, >=,
2716                             drrw->drr_compressed_size);
2717                         ASSERT(!is_meta);
2718                         abuf = arc_loan_compressed_buf(
2719                             dmu_objset_spa(ra->os),
2720                             drrw->drr_compressed_size, drrw->drr_logical_size,
2721                             drrw->drr_compressiontype);
2722                 } else {
2723                         abuf = arc_loan_buf(dmu_objset_spa(ra->os),
2724                             is_meta, drrw->drr_logical_size);
2725                 }
2726
2727                 err = receive_read_payload_and_next_header(ra,
2728                     DRR_WRITE_PAYLOAD_SIZE(drrw), abuf->b_data);
2729                 if (err != 0) {
2730                         dmu_return_arcbuf(abuf);
2731                         return (err);
2732                 }
2733                 ra->rrd->write_buf = abuf;
2734                 receive_read_prefetch(ra, drrw->drr_object, drrw->drr_offset,
2735                     drrw->drr_logical_size);
2736                 return (err);
2737         }
2738         case DRR_WRITE_BYREF:
2739         {
2740                 struct drr_write_byref *drrwb =
2741                     &ra->rrd->header.drr_u.drr_write_byref;
2742                 err = receive_read_payload_and_next_header(ra, 0, NULL);
2743                 receive_read_prefetch(ra, drrwb->drr_object, drrwb->drr_offset,
2744                     drrwb->drr_length);
2745                 return (err);
2746         }
2747         case DRR_WRITE_EMBEDDED:
2748         {
2749                 struct drr_write_embedded *drrwe =
2750                     &ra->rrd->header.drr_u.drr_write_embedded;
2751                 uint32_t size = P2ROUNDUP(drrwe->drr_psize, 8);
2752                 void *buf = kmem_zalloc(size, KM_SLEEP);
2753
2754                 err = receive_read_payload_and_next_header(ra, size, buf);
2755                 if (err != 0) {
2756                         kmem_free(buf, size);
2757                         return (err);
2758                 }
2759
2760                 receive_read_prefetch(ra, drrwe->drr_object, drrwe->drr_offset,
2761                     drrwe->drr_length);
2762                 return (err);
2763         }
2764         case DRR_FREE:
2765         {
2766                 /*
2767                  * It might be beneficial to prefetch indirect blocks here, but
2768                  * we don't really have the data to decide for sure.
2769                  */
2770                 err = receive_read_payload_and_next_header(ra, 0, NULL);
2771                 return (err);
2772         }
2773         case DRR_END:
2774         {
2775                 struct drr_end *drre = &ra->rrd->header.drr_u.drr_end;
2776                 if (!ZIO_CHECKSUM_EQUAL(ra->prev_cksum, drre->drr_checksum))
2777                         return (SET_ERROR(ECKSUM));
2778                 return (0);
2779         }
2780         case DRR_SPILL:
2781         {
2782                 struct drr_spill *drrs = &ra->rrd->header.drr_u.drr_spill;
2783                 void *buf = kmem_zalloc(drrs->drr_length, KM_SLEEP);
2784                 err = receive_read_payload_and_next_header(ra, drrs->drr_length,
2785                     buf);
2786                 if (err != 0)
2787                         kmem_free(buf, drrs->drr_length);
2788                 return (err);
2789         }
2790         default:
2791                 return (SET_ERROR(EINVAL));
2792         }
2793 }
2794
2795 /*
2796  * Commit the records to the pool.
2797  */
2798 static int
2799 receive_process_record(struct receive_writer_arg *rwa,
2800     struct receive_record_arg *rrd)
2801 {
2802         int err;
2803
2804         /* Processing in order, therefore bytes_read should be increasing. */
2805         ASSERT3U(rrd->bytes_read, >=, rwa->bytes_read);
2806         rwa->bytes_read = rrd->bytes_read;
2807
2808         switch (rrd->header.drr_type) {
2809         case DRR_OBJECT:
2810         {
2811                 struct drr_object *drro = &rrd->header.drr_u.drr_object;
2812                 err = receive_object(rwa, drro, rrd->payload);
2813                 kmem_free(rrd->payload, rrd->payload_size);
2814                 rrd->payload = NULL;
2815                 return (err);
2816         }
2817         case DRR_FREEOBJECTS:
2818         {
2819                 struct drr_freeobjects *drrfo =
2820                     &rrd->header.drr_u.drr_freeobjects;
2821                 return (receive_freeobjects(rwa, drrfo));
2822         }
2823         case DRR_WRITE:
2824         {
2825                 struct drr_write *drrw = &rrd->header.drr_u.drr_write;
2826                 err = receive_write(rwa, drrw, rrd->write_buf);
2827                 /* if receive_write() is successful, it consumes the arc_buf */
2828                 if (err != 0)
2829                         dmu_return_arcbuf(rrd->write_buf);
2830                 rrd->write_buf = NULL;
2831                 rrd->payload = NULL;
2832                 return (err);
2833         }
2834         case DRR_WRITE_BYREF:
2835         {
2836                 struct drr_write_byref *drrwbr =
2837                     &rrd->header.drr_u.drr_write_byref;
2838                 return (receive_write_byref(rwa, drrwbr));
2839         }
2840         case DRR_WRITE_EMBEDDED:
2841         {
2842                 struct drr_write_embedded *drrwe =
2843                     &rrd->header.drr_u.drr_write_embedded;
2844                 err = receive_write_embedded(rwa, drrwe, rrd->payload);
2845                 kmem_free(rrd->payload, rrd->payload_size);
2846                 rrd->payload = NULL;
2847                 return (err);
2848         }
2849         case DRR_FREE:
2850         {
2851                 struct drr_free *drrf = &rrd->header.drr_u.drr_free;
2852                 return (receive_free(rwa, drrf));
2853         }
2854         case DRR_SPILL:
2855         {
2856                 struct drr_spill *drrs = &rrd->header.drr_u.drr_spill;
2857                 err = receive_spill(rwa, drrs, rrd->payload);
2858                 kmem_free(rrd->payload, rrd->payload_size);
2859                 rrd->payload = NULL;
2860                 return (err);
2861         }
2862         default:
2863                 return (SET_ERROR(EINVAL));
2864         }
2865 }
2866
2867 /*
2868  * dmu_recv_stream's worker thread; pull records off the queue, and then call
2869  * receive_process_record  When we're done, signal the main thread and exit.
2870  */
2871 static void
2872 receive_writer_thread(void *arg)
2873 {
2874         struct receive_writer_arg *rwa = arg;
2875         struct receive_record_arg *rrd;
2876         for (rrd = bqueue_dequeue(&rwa->q); !rrd->eos_marker;
2877             rrd = bqueue_dequeue(&rwa->q)) {
2878                 /*
2879                  * If there's an error, the main thread will stop putting things
2880                  * on the queue, but we need to clear everything in it before we
2881                  * can exit.
2882                  */
2883                 if (rwa->err == 0) {
2884                         rwa->err = receive_process_record(rwa, rrd);
2885                 } else if (rrd->write_buf != NULL) {
2886                         dmu_return_arcbuf(rrd->write_buf);
2887                         rrd->write_buf = NULL;
2888                         rrd->payload = NULL;
2889                 } else if (rrd->payload != NULL) {
2890                         kmem_free(rrd->payload, rrd->payload_size);
2891                         rrd->payload = NULL;
2892                 }
2893                 kmem_free(rrd, sizeof (*rrd));
2894         }
2895         kmem_free(rrd, sizeof (*rrd));
2896         mutex_enter(&rwa->mutex);
2897         rwa->done = B_TRUE;
2898         cv_signal(&rwa->cv);
2899         mutex_exit(&rwa->mutex);
2900         thread_exit();
2901 }
2902
2903 static int
2904 resume_check(struct receive_arg *ra, nvlist_t *begin_nvl)
2905 {
2906         uint64_t val;
2907         objset_t *mos = dmu_objset_pool(ra->os)->dp_meta_objset;
2908         uint64_t dsobj = dmu_objset_id(ra->os);
2909         uint64_t resume_obj, resume_off;
2910
2911         if (nvlist_lookup_uint64(begin_nvl,
2912             "resume_object", &resume_obj) != 0 ||
2913             nvlist_lookup_uint64(begin_nvl,
2914             "resume_offset", &resume_off) != 0) {
2915                 return (SET_ERROR(EINVAL));
2916         }
2917         VERIFY0(zap_lookup(mos, dsobj,
2918             DS_FIELD_RESUME_OBJECT, sizeof (val), 1, &val));
2919         if (resume_obj != val)
2920                 return (SET_ERROR(EINVAL));
2921         VERIFY0(zap_lookup(mos, dsobj,
2922             DS_FIELD_RESUME_OFFSET, sizeof (val), 1, &val));
2923         if (resume_off != val)
2924                 return (SET_ERROR(EINVAL));
2925
2926         return (0);
2927 }
2928
2929 /*
2930  * Read in the stream's records, one by one, and apply them to the pool.  There
2931  * are two threads involved; the thread that calls this function will spin up a
2932  * worker thread, read the records off the stream one by one, and issue
2933  * prefetches for any necessary indirect blocks.  It will then push the records
2934  * onto an internal blocking queue.  The worker thread will pull the records off
2935  * the queue, and actually write the data into the DMU.  This way, the worker
2936  * thread doesn't have to wait for reads to complete, since everything it needs
2937  * (the indirect blocks) will be prefetched.
2938  *
2939  * NB: callers *must* call dmu_recv_end() if this succeeds.
2940  */
2941 int
2942 dmu_recv_stream(dmu_recv_cookie_t *drc, struct file *fp, offset_t *voffp,
2943     int cleanup_fd, uint64_t *action_handlep)
2944 {
2945         int err = 0;
2946         struct receive_arg ra = { 0 };
2947         struct receive_writer_arg rwa = { 0 };
2948         int featureflags;
2949         nvlist_t *begin_nvl = NULL;
2950
2951         ra.byteswap = drc->drc_byteswap;
2952         ra.cksum = drc->drc_cksum;
2953         ra.td = curthread;
2954         ra.fp = fp;
2955         ra.voff = *voffp;
2956
2957         if (dsl_dataset_is_zapified(drc->drc_ds)) {
2958                 (void) zap_lookup(drc->drc_ds->ds_dir->dd_pool->dp_meta_objset,
2959                     drc->drc_ds->ds_object, DS_FIELD_RESUME_BYTES,
2960                     sizeof (ra.bytes_read), 1, &ra.bytes_read);
2961         }
2962
2963         objlist_create(&ra.ignore_objlist);
2964
2965         /* these were verified in dmu_recv_begin */
2966         ASSERT3U(DMU_GET_STREAM_HDRTYPE(drc->drc_drrb->drr_versioninfo), ==,
2967             DMU_SUBSTREAM);
2968         ASSERT3U(drc->drc_drrb->drr_type, <, DMU_OST_NUMTYPES);
2969
2970         /*
2971          * Open the objset we are modifying.
2972          */
2973         VERIFY0(dmu_objset_from_ds(drc->drc_ds, &ra.os));
2974
2975         ASSERT(dsl_dataset_phys(drc->drc_ds)->ds_flags & DS_FLAG_INCONSISTENT);
2976
2977         featureflags = DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo);
2978
2979         /* if this stream is dedup'ed, set up the avl tree for guid mapping */
2980         if (featureflags & DMU_BACKUP_FEATURE_DEDUP) {
2981                 minor_t minor;
2982
2983                 if (cleanup_fd == -1) {
2984                         ra.err = SET_ERROR(EBADF);
2985                         goto out;
2986                 }
2987                 ra.err = zfs_onexit_fd_hold(cleanup_fd, &minor);
2988                 if (ra.err != 0) {
2989                         cleanup_fd = -1;
2990                         goto out;
2991                 }
2992
2993                 if (*action_handlep == 0) {
2994                         rwa.guid_to_ds_map =
2995                             kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
2996                         avl_create(rwa.guid_to_ds_map, guid_compare,
2997                             sizeof (guid_map_entry_t),
2998                             offsetof(guid_map_entry_t, avlnode));
2999                         err = zfs_onexit_add_cb(minor,
3000                             free_guid_map_onexit, rwa.guid_to_ds_map,
3001                             action_handlep);
3002                         if (ra.err != 0)
3003                                 goto out;
3004                 } else {
3005                         err = zfs_onexit_cb_data(minor, *action_handlep,
3006                             (void **)&rwa.guid_to_ds_map);
3007                         if (ra.err != 0)
3008                                 goto out;
3009                 }
3010
3011                 drc->drc_guid_to_ds_map = rwa.guid_to_ds_map;
3012         }
3013
3014         uint32_t payloadlen = drc->drc_drr_begin->drr_payloadlen;
3015         void *payload = NULL;
3016         if (payloadlen != 0)
3017                 payload = kmem_alloc(payloadlen, KM_SLEEP);
3018
3019         err = receive_read_payload_and_next_header(&ra, payloadlen, payload);
3020         if (err != 0) {
3021                 if (payloadlen != 0)
3022                         kmem_free(payload, payloadlen);
3023                 goto out;
3024         }
3025         if (payloadlen != 0) {
3026                 err = nvlist_unpack(payload, payloadlen, &begin_nvl, KM_SLEEP);
3027                 kmem_free(payload, payloadlen);
3028                 if (err != 0)
3029                         goto out;
3030         }
3031
3032         if (featureflags & DMU_BACKUP_FEATURE_RESUMING) {
3033                 err = resume_check(&ra, begin_nvl);
3034                 if (err != 0)
3035                         goto out;
3036         }
3037
3038         (void) bqueue_init(&rwa.q, zfs_recv_queue_length,
3039             offsetof(struct receive_record_arg, node));
3040         cv_init(&rwa.cv, NULL, CV_DEFAULT, NULL);
3041         mutex_init(&rwa.mutex, NULL, MUTEX_DEFAULT, NULL);
3042         rwa.os = ra.os;
3043         rwa.byteswap = drc->drc_byteswap;
3044         rwa.resumable = drc->drc_resumable;
3045
3046         (void) thread_create(NULL, 0, receive_writer_thread, &rwa, 0, &p0,
3047             TS_RUN, minclsyspri);
3048         /*
3049          * We're reading rwa.err without locks, which is safe since we are the
3050          * only reader, and the worker thread is the only writer.  It's ok if we
3051          * miss a write for an iteration or two of the loop, since the writer
3052          * thread will keep freeing records we send it until we send it an eos
3053          * marker.
3054          *
3055          * We can leave this loop in 3 ways:  First, if rwa.err is
3056          * non-zero.  In that case, the writer thread will free the rrd we just
3057          * pushed.  Second, if  we're interrupted; in that case, either it's the
3058          * first loop and ra.rrd was never allocated, or it's later, and ra.rrd
3059          * has been handed off to the writer thread who will free it.  Finally,
3060          * if receive_read_record fails or we're at the end of the stream, then
3061          * we free ra.rrd and exit.
3062          */
3063         while (rwa.err == 0) {
3064                 if (issig(JUSTLOOKING) && issig(FORREAL)) {
3065                         err = SET_ERROR(EINTR);
3066                         break;
3067                 }
3068
3069                 ASSERT3P(ra.rrd, ==, NULL);
3070                 ra.rrd = ra.next_rrd;
3071                 ra.next_rrd = NULL;
3072                 /* Allocates and loads header into ra.next_rrd */
3073                 err = receive_read_record(&ra);
3074
3075                 if (ra.rrd->header.drr_type == DRR_END || err != 0) {
3076                         kmem_free(ra.rrd, sizeof (*ra.rrd));
3077                         ra.rrd = NULL;
3078                         break;
3079                 }
3080
3081                 bqueue_enqueue(&rwa.q, ra.rrd,
3082                     sizeof (struct receive_record_arg) + ra.rrd->payload_size);
3083                 ra.rrd = NULL;
3084         }
3085         if (ra.next_rrd == NULL)
3086                 ra.next_rrd = kmem_zalloc(sizeof (*ra.next_rrd), KM_SLEEP);
3087         ra.next_rrd->eos_marker = B_TRUE;
3088         bqueue_enqueue(&rwa.q, ra.next_rrd, 1);
3089
3090         mutex_enter(&rwa.mutex);
3091         while (!rwa.done) {
3092                 cv_wait(&rwa.cv, &rwa.mutex);
3093         }
3094         mutex_exit(&rwa.mutex);
3095
3096         cv_destroy(&rwa.cv);
3097         mutex_destroy(&rwa.mutex);
3098         bqueue_destroy(&rwa.q);
3099         if (err == 0)
3100                 err = rwa.err;
3101
3102 out:
3103         nvlist_free(begin_nvl);
3104         if ((featureflags & DMU_BACKUP_FEATURE_DEDUP) && (cleanup_fd != -1))
3105                 zfs_onexit_fd_rele(cleanup_fd);
3106
3107         if (err != 0) {
3108                 /*
3109                  * Clean up references. If receive is not resumable,
3110                  * destroy what we created, so we don't leave it in
3111                  * the inconsistent state.
3112                  */
3113                 dmu_recv_cleanup_ds(drc);
3114         }
3115
3116         *voffp = ra.voff;
3117         objlist_destroy(&ra.ignore_objlist);
3118         return (err);
3119 }
3120
3121 static int
3122 dmu_recv_end_check(void *arg, dmu_tx_t *tx)
3123 {
3124         dmu_recv_cookie_t *drc = arg;
3125         dsl_pool_t *dp = dmu_tx_pool(tx);
3126         int error;
3127
3128         ASSERT3P(drc->drc_ds->ds_owner, ==, dmu_recv_tag);
3129
3130         if (!drc->drc_newfs) {
3131                 dsl_dataset_t *origin_head;
3132
3133                 error = dsl_dataset_hold(dp, drc->drc_tofs, FTAG, &origin_head);
3134                 if (error != 0)
3135                         return (error);
3136                 if (drc->drc_force) {
3137                         /*
3138                          * We will destroy any snapshots in tofs (i.e. before
3139                          * origin_head) that are after the origin (which is
3140                          * the snap before drc_ds, because drc_ds can not
3141                          * have any snaps of its own).
3142                          */
3143                         uint64_t obj;
3144
3145                         obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3146                         while (obj !=
3147                             dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
3148                                 dsl_dataset_t *snap;
3149                                 error = dsl_dataset_hold_obj(dp, obj, FTAG,
3150                                     &snap);
3151                                 if (error != 0)
3152                                         break;
3153                                 if (snap->ds_dir != origin_head->ds_dir)
3154                                         error = SET_ERROR(EINVAL);
3155                                 if (error == 0)  {
3156                                         error = dsl_destroy_snapshot_check_impl(
3157                                             snap, B_FALSE);
3158                                 }
3159                                 obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
3160                                 dsl_dataset_rele(snap, FTAG);
3161                                 if (error != 0)
3162                                         break;
3163                         }
3164                         if (error != 0) {
3165                                 dsl_dataset_rele(origin_head, FTAG);
3166                                 return (error);
3167                         }
3168                 }
3169                 error = dsl_dataset_clone_swap_check_impl(drc->drc_ds,
3170                     origin_head, drc->drc_force, drc->drc_owner, tx);
3171                 if (error != 0) {
3172                         dsl_dataset_rele(origin_head, FTAG);
3173                         return (error);
3174                 }
3175                 error = dsl_dataset_snapshot_check_impl(origin_head,
3176                     drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
3177                 dsl_dataset_rele(origin_head, FTAG);
3178                 if (error != 0)
3179                         return (error);
3180
3181                 error = dsl_destroy_head_check_impl(drc->drc_ds, 1);
3182         } else {
3183                 error = dsl_dataset_snapshot_check_impl(drc->drc_ds,
3184                     drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
3185         }
3186         return (error);
3187 }
3188
3189 static void
3190 dmu_recv_end_sync(void *arg, dmu_tx_t *tx)
3191 {
3192         dmu_recv_cookie_t *drc = arg;
3193         dsl_pool_t *dp = dmu_tx_pool(tx);
3194
3195         spa_history_log_internal_ds(drc->drc_ds, "finish receiving",
3196             tx, "snap=%s", drc->drc_tosnap);
3197
3198         if (!drc->drc_newfs) {
3199                 dsl_dataset_t *origin_head;
3200
3201                 VERIFY0(dsl_dataset_hold(dp, drc->drc_tofs, FTAG,
3202                     &origin_head));
3203
3204                 if (drc->drc_force) {
3205                         /*
3206                          * Destroy any snapshots of drc_tofs (origin_head)
3207                          * after the origin (the snap before drc_ds).
3208                          */
3209                         uint64_t obj;
3210
3211                         obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3212                         while (obj !=
3213                             dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
3214                                 dsl_dataset_t *snap;
3215                                 VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG,
3216                                     &snap));
3217                                 ASSERT3P(snap->ds_dir, ==, origin_head->ds_dir);
3218                                 obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
3219                                 dsl_destroy_snapshot_sync_impl(snap,
3220                                     B_FALSE, tx);
3221                                 dsl_dataset_rele(snap, FTAG);
3222                         }
3223                 }
3224                 VERIFY3P(drc->drc_ds->ds_prev, ==,
3225                     origin_head->ds_prev);
3226
3227                 dsl_dataset_clone_swap_sync_impl(drc->drc_ds,
3228                     origin_head, tx);
3229                 dsl_dataset_snapshot_sync_impl(origin_head,
3230                     drc->drc_tosnap, tx);
3231
3232                 /* set snapshot's creation time and guid */
3233                 dmu_buf_will_dirty(origin_head->ds_prev->ds_dbuf, tx);
3234                 dsl_dataset_phys(origin_head->ds_prev)->ds_creation_time =
3235                     drc->drc_drrb->drr_creation_time;
3236                 dsl_dataset_phys(origin_head->ds_prev)->ds_guid =
3237                     drc->drc_drrb->drr_toguid;
3238                 dsl_dataset_phys(origin_head->ds_prev)->ds_flags &=
3239                     ~DS_FLAG_INCONSISTENT;
3240
3241                 dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
3242                 dsl_dataset_phys(origin_head)->ds_flags &=
3243                     ~DS_FLAG_INCONSISTENT;
3244
3245                 drc->drc_newsnapobj =
3246                     dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
3247
3248                 dsl_dataset_rele(origin_head, FTAG);
3249                 dsl_destroy_head_sync_impl(drc->drc_ds, tx);
3250
3251                 if (drc->drc_owner != NULL)
3252                         VERIFY3P(origin_head->ds_owner, ==, drc->drc_owner);
3253         } else {
3254                 dsl_dataset_t *ds = drc->drc_ds;
3255
3256                 dsl_dataset_snapshot_sync_impl(ds, drc->drc_tosnap, tx);
3257
3258                 /* set snapshot's creation time and guid */
3259                 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
3260                 dsl_dataset_phys(ds->ds_prev)->ds_creation_time =
3261                     drc->drc_drrb->drr_creation_time;
3262                 dsl_dataset_phys(ds->ds_prev)->ds_guid =
3263                     drc->drc_drrb->drr_toguid;
3264                 dsl_dataset_phys(ds->ds_prev)->ds_flags &=
3265                     ~DS_FLAG_INCONSISTENT;
3266
3267                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3268                 dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
3269                 if (dsl_dataset_has_resume_receive_state(ds)) {
3270                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3271                             DS_FIELD_RESUME_FROMGUID, tx);
3272                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3273                             DS_FIELD_RESUME_OBJECT, tx);
3274                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3275                             DS_FIELD_RESUME_OFFSET, tx);
3276                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3277                             DS_FIELD_RESUME_BYTES, tx);
3278                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3279                             DS_FIELD_RESUME_TOGUID, tx);
3280                         (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
3281                             DS_FIELD_RESUME_TONAME, tx);
3282                 }
3283                 drc->drc_newsnapobj =
3284                     dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj;
3285         }
3286         /*
3287          * Release the hold from dmu_recv_begin.  This must be done before
3288          * we return to open context, so that when we free the dataset's dnode,
3289          * we can evict its bonus buffer.
3290          */
3291         dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
3292         drc->drc_ds = NULL;
3293 }
3294
3295 static int
3296 add_ds_to_guidmap(const char *name, avl_tree_t *guid_map, uint64_t snapobj)
3297 {
3298         dsl_pool_t *dp;
3299         dsl_dataset_t *snapds;
3300         guid_map_entry_t *gmep;
3301         int err;
3302
3303         ASSERT(guid_map != NULL);
3304
3305         err = dsl_pool_hold(name, FTAG, &dp);
3306         if (err != 0)
3307                 return (err);
3308         gmep = kmem_alloc(sizeof (*gmep), KM_SLEEP);
3309         err = dsl_dataset_hold_obj(dp, snapobj, gmep, &snapds);
3310         if (err == 0) {
3311                 gmep->guid = dsl_dataset_phys(snapds)->ds_guid;
3312                 gmep->gme_ds = snapds;
3313                 avl_add(guid_map, gmep);
3314                 dsl_dataset_long_hold(snapds, gmep);
3315         } else
3316                 kmem_free(gmep, sizeof (*gmep));
3317
3318         dsl_pool_rele(dp, FTAG);
3319         return (err);
3320 }
3321
3322 static int dmu_recv_end_modified_blocks = 3;
3323
3324 static int
3325 dmu_recv_existing_end(dmu_recv_cookie_t *drc)
3326 {
3327 #ifdef _KERNEL
3328         /*
3329          * We will be destroying the ds; make sure its origin is unmounted if
3330          * necessary.
3331          */
3332         char name[ZFS_MAX_DATASET_NAME_LEN];
3333         dsl_dataset_name(drc->drc_ds, name);
3334         zfs_destroy_unmount_origin(name);
3335 #endif
3336
3337         return (dsl_sync_task(drc->drc_tofs,
3338             dmu_recv_end_check, dmu_recv_end_sync, drc,
3339             dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL));
3340 }
3341
3342 static int
3343 dmu_recv_new_end(dmu_recv_cookie_t *drc)
3344 {
3345         return (dsl_sync_task(drc->drc_tofs,
3346             dmu_recv_end_check, dmu_recv_end_sync, drc,
3347             dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL));
3348 }
3349
3350 int
3351 dmu_recv_end(dmu_recv_cookie_t *drc, void *owner)
3352 {
3353         int error;
3354
3355         drc->drc_owner = owner;
3356
3357         if (drc->drc_newfs)
3358                 error = dmu_recv_new_end(drc);
3359         else
3360                 error = dmu_recv_existing_end(drc);
3361
3362         if (error != 0) {
3363                 dmu_recv_cleanup_ds(drc);
3364         } else if (drc->drc_guid_to_ds_map != NULL) {
3365                 (void) add_ds_to_guidmap(drc->drc_tofs,
3366                     drc->drc_guid_to_ds_map,
3367                     drc->drc_newsnapobj);
3368         }
3369         return (error);
3370 }
3371
3372 /*
3373  * Return TRUE if this objset is currently being received into.
3374  */
3375 boolean_t
3376 dmu_objset_is_receiving(objset_t *os)
3377 {
3378         return (os->os_dsl_dataset != NULL &&
3379             os->os_dsl_dataset->ds_owner == dmu_recv_tag);
3380 }