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