module/zfs/dsl_dataset.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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/dmu_objset.h>
  27 #include <sys/dsl_dataset.h>
  28 #include <sys/dsl_dir.h>
  29 #include <sys/dsl_prop.h>
  30 #include <sys/dsl_synctask.h>
  31 #include <sys/dmu_traverse.h>
  32 #include <sys/dmu_tx.h>
  33 #include <sys/arc.h>
  34 #include <sys/zio.h>
  35 #include <sys/zap.h>
  36 #include <sys/unique.h>
  37 #include <sys/zfs_context.h>
  38 #include <sys/zfs_ioctl.h>
  39 #include <sys/spa.h>
  40 #include <sys/zfs_znode.h>
  41 #include <sys/sunddi.h>
  42
  43 static char *dsl_reaper = "the grim reaper";
  44
  45 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
  46 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
  47 static dsl_checkfunc_t dsl_dataset_rollback_check;
  48 static dsl_syncfunc_t dsl_dataset_rollback_sync;
  49 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
  50
  51 #define DS_REF_MAX      (1ULL << 62)
  52
  53 #define DSL_DEADLIST_BLOCKSIZE  SPA_MAXBLOCKSIZE
  54
  55 #define DSL_DATASET_IS_DESTROYED(ds)    ((ds)->ds_owner == dsl_reaper)
  56
  57
  58 /*
  59  * Figure out how much of this delta should be propogated to the dsl_dir
  60  * layer.  If there's a refreservation, that space has already been
  61  * partially accounted for in our ancestors.
  62  */
  63 static int64_t
  64 parent_delta(dsl_dataset_t *ds, int64_t delta)
  65 {
  66         uint64_t old_bytes, new_bytes;
  67
  68         if (ds->ds_reserved == 0)
  69                 return (delta);
  70
  71         old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
  72         new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
  73
  74         ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
  75         return (new_bytes - old_bytes);
  76 }
  77
  78 void
  79 dsl_dataset_block_born(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
  80 {
  81         int used = bp_get_dasize(tx->tx_pool->dp_spa, bp);
  82         int compressed = BP_GET_PSIZE(bp);
  83         int uncompressed = BP_GET_UCSIZE(bp);
  84         int64_t delta;
  85
  86         dprintf_bp(bp, "born, ds=%p\n", ds);
  87
  88         ASSERT(dmu_tx_is_syncing(tx));
  89         /* It could have been compressed away to nothing */
  90         if (BP_IS_HOLE(bp))
  91                 return;
  92         ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
  93         ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
  94         if (ds == NULL) {
  95                 /*
  96                  * Account for the meta-objset space in its placeholder
  97                  * dsl_dir.
  98                  */
  99                 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
 100                 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
 101                     used, compressed, uncompressed, tx);
 102                 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
 103                 return;
 104         }
 105         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 106         mutex_enter(&ds->ds_dir->dd_lock);
 107         mutex_enter(&ds->ds_lock);
 108         delta = parent_delta(ds, used);
 109         ds->ds_phys->ds_used_bytes += used;
 110         ds->ds_phys->ds_compressed_bytes += compressed;
 111         ds->ds_phys->ds_uncompressed_bytes += uncompressed;
 112         ds->ds_phys->ds_unique_bytes += used;
 113         mutex_exit(&ds->ds_lock);
 114         dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
 115             compressed, uncompressed, tx);
 116         dsl_dir_transfer_space(ds->ds_dir, used - delta,
 117             DD_USED_REFRSRV, DD_USED_HEAD, tx);
 118         mutex_exit(&ds->ds_dir->dd_lock);
 119 }
 120
 121 int
 122 dsl_dataset_block_kill(dsl_dataset_t *ds, blkptr_t *bp, zio_t *pio,
 123     dmu_tx_t *tx)
 124 {
 125         int used = bp_get_dasize(tx->tx_pool->dp_spa, bp);
 126         int compressed = BP_GET_PSIZE(bp);
 127         int uncompressed = BP_GET_UCSIZE(bp);
 128
 129         ASSERT(pio != NULL);
 130         ASSERT(dmu_tx_is_syncing(tx));
 131         /* No block pointer => nothing to free */
 132         if (BP_IS_HOLE(bp))
 133                 return (0);
 134
 135         ASSERT(used > 0);
 136         if (ds == NULL) {
 137                 int err;
 138                 /*
 139                  * Account for the meta-objset space in its placeholder
 140                  * dataset.
 141                  */
 142                 err = dsl_free(pio, tx->tx_pool,
 143                     tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT);
 144                 ASSERT(err == 0);
 145
 146                 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
 147                     -used, -compressed, -uncompressed, tx);
 148                 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
 149                 return (used);
 150         }
 151         ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
 152
 153         ASSERT(!dsl_dataset_is_snapshot(ds));
 154         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 155
 156         if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
 157                 int err;
 158                 int64_t delta;
 159
 160                 dprintf_bp(bp, "freeing: %s", "");
 161                 err = dsl_free(pio, tx->tx_pool,
 162                     tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT);
 163                 ASSERT(err == 0);
 164
 165                 mutex_enter(&ds->ds_dir->dd_lock);
 166                 mutex_enter(&ds->ds_lock);
 167                 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
 168                     !DS_UNIQUE_IS_ACCURATE(ds));
 169                 delta = parent_delta(ds, -used);
 170                 ds->ds_phys->ds_unique_bytes -= used;
 171                 mutex_exit(&ds->ds_lock);
 172                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
 173                     delta, -compressed, -uncompressed, tx);
 174                 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
 175                     DD_USED_REFRSRV, DD_USED_HEAD, tx);
 176                 mutex_exit(&ds->ds_dir->dd_lock);
 177         } else {
 178                 dprintf_bp(bp, "putting on dead list: %s", "");
 179                 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, bp, tx));
 180                 ASSERT3U(ds->ds_prev->ds_object, ==,
 181                     ds->ds_phys->ds_prev_snap_obj);
 182                 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
 183                 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
 184                 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
 185                     ds->ds_object && bp->blk_birth >
 186                     ds->ds_prev->ds_phys->ds_prev_snap_txg) {
 187                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
 188                         mutex_enter(&ds->ds_prev->ds_lock);
 189                         ds->ds_prev->ds_phys->ds_unique_bytes += used;
 190                         mutex_exit(&ds->ds_prev->ds_lock);
 191                 }
 192                 if (bp->blk_birth > ds->ds_origin_txg) {
 193                         dsl_dir_transfer_space(ds->ds_dir, used,
 194                             DD_USED_HEAD, DD_USED_SNAP, tx);
 195                 }
 196         }
 197         mutex_enter(&ds->ds_lock);
 198         ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
 199         ds->ds_phys->ds_used_bytes -= used;
 200         ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
 201         ds->ds_phys->ds_compressed_bytes -= compressed;
 202         ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
 203         ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
 204         mutex_exit(&ds->ds_lock);
 205
 206         return (used);
 207 }
 208
 209 uint64_t
 210 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
 211 {
 212         uint64_t trysnap = 0;
 213
 214         if (ds == NULL)
 215                 return (0);
 216         /*
 217          * The snapshot creation could fail, but that would cause an
 218          * incorrect FALSE return, which would only result in an
 219          * overestimation of the amount of space that an operation would
 220          * consume, which is OK.
 221          *
 222          * There's also a small window where we could miss a pending
 223          * snapshot, because we could set the sync task in the quiescing
 224          * phase.  So this should only be used as a guess.
 225          */
 226         if (ds->ds_trysnap_txg >
 227             spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
 228                 trysnap = ds->ds_trysnap_txg;
 229         return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
 230 }
 231
 232 int
 233 dsl_dataset_block_freeable(dsl_dataset_t *ds, uint64_t blk_birth)
 234 {
 235         return (blk_birth > dsl_dataset_prev_snap_txg(ds));
 236 }
 237
 238 /* ARGSUSED */
 239 static void
 240 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
 241 {
 242         dsl_dataset_t *ds = dsv;
 243
 244         ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
 245
 246         dprintf_ds(ds, "evicting %s\n", "");
 247
 248         unique_remove(ds->ds_fsid_guid);
 249
 250         if (ds->ds_user_ptr != NULL)
 251                 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
 252
 253         if (ds->ds_prev) {
 254                 dsl_dataset_drop_ref(ds->ds_prev, ds);
 255                 ds->ds_prev = NULL;
 256         }
 257
 258         bplist_close(&ds->ds_deadlist);
 259         if (ds->ds_dir)
 260                 dsl_dir_close(ds->ds_dir, ds);
 261
 262         ASSERT(!list_link_active(&ds->ds_synced_link));
 263
 264         mutex_destroy(&ds->ds_lock);
 265         mutex_destroy(&ds->ds_opening_lock);
 266         mutex_destroy(&ds->ds_deadlist.bpl_lock);
 267         rw_destroy(&ds->ds_rwlock);
 268         cv_destroy(&ds->ds_exclusive_cv);
 269
 270         kmem_free(ds, sizeof (dsl_dataset_t));
 271 }
 272
 273 static int
 274 dsl_dataset_get_snapname(dsl_dataset_t *ds)
 275 {
 276         dsl_dataset_phys_t *headphys;
 277         int err;
 278         dmu_buf_t *headdbuf;
 279         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 280         objset_t *mos = dp->dp_meta_objset;
 281
 282         if (ds->ds_snapname[0])
 283                 return (0);
 284         if (ds->ds_phys->ds_next_snap_obj == 0)
 285                 return (0);
 286
 287         err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
 288             FTAG, &headdbuf);
 289         if (err)
 290                 return (err);
 291         headphys = headdbuf->db_data;
 292         err = zap_value_search(dp->dp_meta_objset,
 293             headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
 294         dmu_buf_rele(headdbuf, FTAG);
 295         return (err);
 296 }
 297
 298 static int
 299 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
 300 {
 301         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 302         uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
 303         matchtype_t mt;
 304         int err;
 305
 306         if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
 307                 mt = MT_FIRST;
 308         else
 309                 mt = MT_EXACT;
 310
 311         err = zap_lookup_norm(mos, snapobj, name, 8, 1,
 312             value, mt, NULL, 0, NULL);
 313         if (err == ENOTSUP && mt == MT_FIRST)
 314                 err = zap_lookup(mos, snapobj, name, 8, 1, value);
 315         return (err);
 316 }
 317
 318 static int
 319 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
 320 {
 321         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 322         uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
 323         matchtype_t mt;
 324         int err;
 325
 326         if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
 327                 mt = MT_FIRST;
 328         else
 329                 mt = MT_EXACT;
 330
 331         err = zap_remove_norm(mos, snapobj, name, mt, tx);
 332         if (err == ENOTSUP && mt == MT_FIRST)
 333                 err = zap_remove(mos, snapobj, name, tx);
 334         return (err);
 335 }
 336
 337 static int
 338 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 339     dsl_dataset_t **dsp)
 340 {
 341         objset_t *mos = dp->dp_meta_objset;
 342         dmu_buf_t *dbuf;
 343         dsl_dataset_t *ds;
 344         int err;
 345
 346         ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
 347             dsl_pool_sync_context(dp));
 348
 349         err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
 350         if (err)
 351                 return (err);
 352         ds = dmu_buf_get_user(dbuf);
 353         if (ds == NULL) {
 354                 dsl_dataset_t *winner;
 355
 356                 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
 357                 ds->ds_dbuf = dbuf;
 358                 ds->ds_object = dsobj;
 359                 ds->ds_phys = dbuf->db_data;
 360
 361                 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
 362                 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
 363                 mutex_init(&ds->ds_deadlist.bpl_lock, NULL, MUTEX_DEFAULT,
 364                     NULL);
 365                 rw_init(&ds->ds_rwlock, 0, 0, 0);
 366                 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
 367
 368                 err = bplist_open(&ds->ds_deadlist,
 369                     mos, ds->ds_phys->ds_deadlist_obj);
 370                 if (err == 0) {
 371                         err = dsl_dir_open_obj(dp,
 372                             ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
 373                 }
 374                 if (err) {
 375                         /*
 376                          * we don't really need to close the blist if we
 377                          * just opened it.
 378                          */
 379                         mutex_destroy(&ds->ds_lock);
 380                         mutex_destroy(&ds->ds_opening_lock);
 381                         mutex_destroy(&ds->ds_deadlist.bpl_lock);
 382                         rw_destroy(&ds->ds_rwlock);
 383                         cv_destroy(&ds->ds_exclusive_cv);
 384                         kmem_free(ds, sizeof (dsl_dataset_t));
 385                         dmu_buf_rele(dbuf, tag);
 386                         return (err);
 387                 }
 388
 389                 if (!dsl_dataset_is_snapshot(ds)) {
 390                         ds->ds_snapname[0] = '\0';
 391                         if (ds->ds_phys->ds_prev_snap_obj) {
 392                                 err = dsl_dataset_get_ref(dp,
 393                                     ds->ds_phys->ds_prev_snap_obj,
 394                                     ds, &ds->ds_prev);
 395                         }
 396
 397                         if (err == 0 && dsl_dir_is_clone(ds->ds_dir)) {
 398                                 dsl_dataset_t *origin;
 399
 400                                 err = dsl_dataset_hold_obj(dp,
 401                                     ds->ds_dir->dd_phys->dd_origin_obj,
 402                                     FTAG, &origin);
 403                                 if (err == 0) {
 404                                         ds->ds_origin_txg =
 405                                             origin->ds_phys->ds_creation_txg;
 406                                         dsl_dataset_rele(origin, FTAG);
 407                                 }
 408                         }
 409                 } else if (zfs_flags & ZFS_DEBUG_SNAPNAMES) {
 410                         err = dsl_dataset_get_snapname(ds);
 411                 }
 412
 413                 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
 414                         /*
 415                          * In sync context, we're called with either no lock
 416                          * or with the write lock.  If we're not syncing,
 417                          * we're always called with the read lock held.
 418                          */
 419                         boolean_t need_lock =
 420                             !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
 421                             dsl_pool_sync_context(dp);
 422
 423                         if (need_lock)
 424                                 rw_enter(&dp->dp_config_rwlock, RW_READER);
 425
 426                         err = dsl_prop_get_ds(ds,
 427                             "refreservation", sizeof (uint64_t), 1,
 428                             &ds->ds_reserved, NULL);
 429                         if (err == 0) {
 430                                 err = dsl_prop_get_ds(ds,
 431                                     "refquota", sizeof (uint64_t), 1,
 432                                     &ds->ds_quota, NULL);
 433                         }
 434
 435                         if (need_lock)
 436                                 rw_exit(&dp->dp_config_rwlock);
 437                 } else {
 438                         ds->ds_reserved = ds->ds_quota = 0;
 439                 }
 440
 441                 if (err == 0) {
 442                         winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
 443                             dsl_dataset_evict);
 444                 }
 445                 if (err || winner) {
 446                         bplist_close(&ds->ds_deadlist);
 447                         if (ds->ds_prev)
 448                                 dsl_dataset_drop_ref(ds->ds_prev, ds);
 449                         dsl_dir_close(ds->ds_dir, ds);
 450                         mutex_destroy(&ds->ds_lock);
 451                         mutex_destroy(&ds->ds_opening_lock);
 452                         mutex_destroy(&ds->ds_deadlist.bpl_lock);
 453                         rw_destroy(&ds->ds_rwlock);
 454                         cv_destroy(&ds->ds_exclusive_cv);
 455                         kmem_free(ds, sizeof (dsl_dataset_t));
 456                         if (err) {
 457                                 dmu_buf_rele(dbuf, tag);
 458                                 return (err);
 459                         }
 460                         ds = winner;
 461                 } else {
 462                         ds->ds_fsid_guid =
 463                             unique_insert(ds->ds_phys->ds_fsid_guid);
 464                 }
 465         }
 466         ASSERT3P(ds->ds_dbuf, ==, dbuf);
 467         ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
 468         ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
 469             spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
 470             dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
 471         mutex_enter(&ds->ds_lock);
 472         if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
 473                 mutex_exit(&ds->ds_lock);
 474                 dmu_buf_rele(ds->ds_dbuf, tag);
 475                 return (ENOENT);
 476         }
 477         mutex_exit(&ds->ds_lock);
 478         *dsp = ds;
 479         return (0);
 480 }
 481
 482 static int
 483 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
 484 {
 485         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 486
 487         /*
 488          * In syncing context we don't want the rwlock lock: there
 489          * may be an existing writer waiting for sync phase to
 490          * finish.  We don't need to worry about such writers, since
 491          * sync phase is single-threaded, so the writer can't be
 492          * doing anything while we are active.
 493          */
 494         if (dsl_pool_sync_context(dp)) {
 495                 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
 496                 return (0);
 497         }
 498
 499         /*
 500          * Normal users will hold the ds_rwlock as a READER until they
 501          * are finished (i.e., call dsl_dataset_rele()).  "Owners" will
 502          * drop their READER lock after they set the ds_owner field.
 503          *
 504          * If the dataset is being destroyed, the destroy thread will
 505          * obtain a WRITER lock for exclusive access after it's done its
 506          * open-context work and then change the ds_owner to
 507          * dsl_reaper once destruction is assured.  So threads
 508          * may block here temporarily, until the "destructability" of
 509          * the dataset is determined.
 510          */
 511         ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
 512         mutex_enter(&ds->ds_lock);
 513         while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
 514                 rw_exit(&dp->dp_config_rwlock);
 515                 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
 516                 if (DSL_DATASET_IS_DESTROYED(ds)) {
 517                         mutex_exit(&ds->ds_lock);
 518                         dsl_dataset_drop_ref(ds, tag);
 519                         rw_enter(&dp->dp_config_rwlock, RW_READER);
 520                         return (ENOENT);
 521                 }
 522                 rw_enter(&dp->dp_config_rwlock, RW_READER);
 523         }
 524         mutex_exit(&ds->ds_lock);
 525         return (0);
 526 }
 527
 528 int
 529 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 530     dsl_dataset_t **dsp)
 531 {
 532         int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
 533
 534         if (err)
 535                 return (err);
 536         return (dsl_dataset_hold_ref(*dsp, tag));
 537 }
 538
 539 int
 540 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, int flags, void *owner,
 541     dsl_dataset_t **dsp)
 542 {
 543         int err = dsl_dataset_hold_obj(dp, dsobj, owner, dsp);
 544
 545         ASSERT(DS_MODE_TYPE(flags) != DS_MODE_USER);
 546
 547         if (err)
 548                 return (err);
 549         if (!dsl_dataset_tryown(*dsp, DS_MODE_IS_INCONSISTENT(flags), owner)) {
 550                 dsl_dataset_rele(*dsp, owner);
 551                 return (EBUSY);
 552         }
 553         return (0);
 554 }
 555
 556 int
 557 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
 558 {
 559         dsl_dir_t *dd;
 560         dsl_pool_t *dp;
 561         const char *snapname;
 562         uint64_t obj;
 563         int err = 0;
 564
 565         err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
 566         if (err)
 567                 return (err);
 568
 569         dp = dd->dd_pool;
 570         obj = dd->dd_phys->dd_head_dataset_obj;
 571         rw_enter(&dp->dp_config_rwlock, RW_READER);
 572         if (obj)
 573                 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
 574         else
 575                 err = ENOENT;
 576         if (err)
 577                 goto out;
 578
 579         err = dsl_dataset_hold_ref(*dsp, tag);
 580
 581         /* we may be looking for a snapshot */
 582         if (err == 0 && snapname != NULL) {
 583                 dsl_dataset_t *ds = NULL;
 584
 585                 if (*snapname++ != '@') {
 586                         dsl_dataset_rele(*dsp, tag);
 587                         err = ENOENT;
 588                         goto out;
 589                 }
 590
 591                 dprintf("looking for snapshot '%s'\n", snapname);
 592                 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
 593                 if (err == 0)
 594                         err = dsl_dataset_get_ref(dp, obj, tag, &ds);
 595                 dsl_dataset_rele(*dsp, tag);
 596
 597                 ASSERT3U((err == 0), ==, (ds != NULL));
 598
 599                 if (ds) {
 600                         mutex_enter(&ds->ds_lock);
 601                         if (ds->ds_snapname[0] == 0)
 602                                 (void) strlcpy(ds->ds_snapname, snapname,
 603                                     sizeof (ds->ds_snapname));
 604                         mutex_exit(&ds->ds_lock);
 605                         err = dsl_dataset_hold_ref(ds, tag);
 606                         *dsp = err ? NULL : ds;
 607                 }
 608         }
 609 out:
 610         rw_exit(&dp->dp_config_rwlock);
 611         dsl_dir_close(dd, FTAG);
 612         return (err);
 613 }
 614
 615 int
 616 dsl_dataset_own(const char *name, int flags, void *owner, dsl_dataset_t **dsp)
 617 {
 618         int err = dsl_dataset_hold(name, owner, dsp);
 619         if (err)
 620                 return (err);
 621         if ((*dsp)->ds_phys->ds_num_children > 0 &&
 622             !DS_MODE_IS_READONLY(flags)) {
 623                 dsl_dataset_rele(*dsp, owner);
 624                 return (EROFS);
 625         }
 626         if (!dsl_dataset_tryown(*dsp, DS_MODE_IS_INCONSISTENT(flags), owner)) {
 627                 dsl_dataset_rele(*dsp, owner);
 628                 return (EBUSY);
 629         }
 630         return (0);
 631 }
 632
 633 void
 634 dsl_dataset_name(dsl_dataset_t *ds, char *name)
 635 {
 636         if (ds == NULL) {
 637                 (void) strcpy(name, "mos");
 638         } else {
 639                 dsl_dir_name(ds->ds_dir, name);
 640                 VERIFY(0 == dsl_dataset_get_snapname(ds));
 641                 if (ds->ds_snapname[0]) {
 642                         (void) strcat(name, "@");
 643                         /*
 644                          * We use a "recursive" mutex so that we
 645                          * can call dprintf_ds() with ds_lock held.
 646                          */
 647                         if (!MUTEX_HELD(&ds->ds_lock)) {
 648                                 mutex_enter(&ds->ds_lock);
 649                                 (void) strcat(name, ds->ds_snapname);
 650                                 mutex_exit(&ds->ds_lock);
 651                         } else {
 652                                 (void) strcat(name, ds->ds_snapname);
 653                         }
 654                 }
 655         }
 656 }
 657
 658 static int
 659 dsl_dataset_namelen(dsl_dataset_t *ds)
 660 {
 661         int result;
 662
 663         if (ds == NULL) {
 664                 result = 3;     /* "mos" */
 665         } else {
 666                 result = dsl_dir_namelen(ds->ds_dir);
 667                 VERIFY(0 == dsl_dataset_get_snapname(ds));
 668                 if (ds->ds_snapname[0]) {
 669                         ++result;       /* adding one for the @-sign */
 670                         if (!MUTEX_HELD(&ds->ds_lock)) {
 671                                 mutex_enter(&ds->ds_lock);
 672                                 result += strlen(ds->ds_snapname);
 673                                 mutex_exit(&ds->ds_lock);
 674                         } else {
 675                                 result += strlen(ds->ds_snapname);
 676                         }
 677                 }
 678         }
 679
 680         return (result);
 681 }
 682
 683 void
 684 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
 685 {
 686         dmu_buf_rele(ds->ds_dbuf, tag);
 687 }
 688
 689 void
 690 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
 691 {
 692         if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
 693                 rw_exit(&ds->ds_rwlock);
 694         }
 695         dsl_dataset_drop_ref(ds, tag);
 696 }
 697
 698 void
 699 dsl_dataset_disown(dsl_dataset_t *ds, void *owner)
 700 {
 701         ASSERT((ds->ds_owner == owner && ds->ds_dbuf) ||
 702             (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
 703
 704         mutex_enter(&ds->ds_lock);
 705         ds->ds_owner = NULL;
 706         if (RW_WRITE_HELD(&ds->ds_rwlock)) {
 707                 rw_exit(&ds->ds_rwlock);
 708                 cv_broadcast(&ds->ds_exclusive_cv);
 709         }
 710         mutex_exit(&ds->ds_lock);
 711         if (ds->ds_dbuf)
 712                 dsl_dataset_drop_ref(ds, owner);
 713         else
 714                 dsl_dataset_evict(ds->ds_dbuf, ds);
 715 }
 716
 717 boolean_t
 718 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *owner)
 719 {
 720         boolean_t gotit = FALSE;
 721
 722         mutex_enter(&ds->ds_lock);
 723         if (ds->ds_owner == NULL &&
 724             (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
 725                 ds->ds_owner = owner;
 726                 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
 727                         rw_exit(&ds->ds_rwlock);
 728                 gotit = TRUE;
 729         }
 730         mutex_exit(&ds->ds_lock);
 731         return (gotit);
 732 }
 733
 734 void
 735 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
 736 {
 737         ASSERT3P(owner, ==, ds->ds_owner);
 738         if (!RW_WRITE_HELD(&ds->ds_rwlock))
 739                 rw_enter(&ds->ds_rwlock, RW_WRITER);
 740 }
 741
 742 uint64_t
 743 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
 744     uint64_t flags, dmu_tx_t *tx)
 745 {
 746         dsl_pool_t *dp = dd->dd_pool;
 747         dmu_buf_t *dbuf;
 748         dsl_dataset_phys_t *dsphys;
 749         uint64_t dsobj;
 750         objset_t *mos = dp->dp_meta_objset;
 751
 752         if (origin == NULL)
 753                 origin = dp->dp_origin_snap;
 754
 755         ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
 756         ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
 757         ASSERT(dmu_tx_is_syncing(tx));
 758         ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
 759
 760         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
 761             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
 762         VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
 763         dmu_buf_will_dirty(dbuf, tx);
 764         dsphys = dbuf->db_data;
 765         bzero(dsphys, sizeof (dsl_dataset_phys_t));
 766         dsphys->ds_dir_obj = dd->dd_object;
 767         dsphys->ds_flags = flags;
 768         dsphys->ds_fsid_guid = unique_create();
 769         (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
 770             sizeof (dsphys->ds_guid));
 771         dsphys->ds_snapnames_zapobj =
 772             zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
 773             DMU_OT_NONE, 0, tx);
 774         dsphys->ds_creation_time = gethrestime_sec();
 775         dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
 776         dsphys->ds_deadlist_obj =
 777             bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
 778
 779         if (origin) {
 780                 dsphys->ds_prev_snap_obj = origin->ds_object;
 781                 dsphys->ds_prev_snap_txg =
 782                     origin->ds_phys->ds_creation_txg;
 783                 dsphys->ds_used_bytes =
 784                     origin->ds_phys->ds_used_bytes;
 785                 dsphys->ds_compressed_bytes =
 786                     origin->ds_phys->ds_compressed_bytes;
 787                 dsphys->ds_uncompressed_bytes =
 788                     origin->ds_phys->ds_uncompressed_bytes;
 789                 dsphys->ds_bp = origin->ds_phys->ds_bp;
 790                 dsphys->ds_flags |= origin->ds_phys->ds_flags;
 791
 792                 dmu_buf_will_dirty(origin->ds_dbuf, tx);
 793                 origin->ds_phys->ds_num_children++;
 794
 795                 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
 796                         if (origin->ds_phys->ds_next_clones_obj == 0) {
 797                                 origin->ds_phys->ds_next_clones_obj =
 798                                     zap_create(mos,
 799                                     DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
 800                         }
 801                         VERIFY(0 == zap_add_int(mos,
 802                             origin->ds_phys->ds_next_clones_obj,
 803                             dsobj, tx));
 804                 }
 805
 806                 dmu_buf_will_dirty(dd->dd_dbuf, tx);
 807                 dd->dd_phys->dd_origin_obj = origin->ds_object;
 808         }
 809
 810         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
 811                 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
 812
 813         dmu_buf_rele(dbuf, FTAG);
 814
 815         dmu_buf_will_dirty(dd->dd_dbuf, tx);
 816         dd->dd_phys->dd_head_dataset_obj = dsobj;
 817
 818         return (dsobj);
 819 }
 820
 821 uint64_t
 822 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
 823     dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
 824 {
 825         dsl_pool_t *dp = pdd->dd_pool;
 826         uint64_t dsobj, ddobj;
 827         dsl_dir_t *dd;
 828
 829         ASSERT(lastname[0] != '@');
 830
 831         ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
 832         VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
 833
 834         dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
 835
 836         dsl_deleg_set_create_perms(dd, tx, cr);
 837
 838         dsl_dir_close(dd, FTAG);
 839
 840         return (dsobj);
 841 }
 842
 843 struct destroyarg {
 844         dsl_sync_task_group_t *dstg;
 845         char *snapname;
 846         char *failed;
 847 };
 848
 849 static int
 850 dsl_snapshot_destroy_one(char *name, void *arg)
 851 {
 852         struct destroyarg *da = arg;
 853         dsl_dataset_t *ds;
 854         char *cp;
 855         int err;
 856
 857         (void) strcat(name, "@");
 858         (void) strcat(name, da->snapname);
 859         err = dsl_dataset_own(name, DS_MODE_READONLY | DS_MODE_INCONSISTENT,
 860             da->dstg, &ds);
 861         cp = strchr(name, '@');
 862         *cp = '\0';
 863         if (err == 0) {
 864                 dsl_dataset_make_exclusive(ds, da->dstg);
 865                 if (ds->ds_user_ptr) {
 866                         ds->ds_user_evict_func(ds, ds->ds_user_ptr);
 867                         ds->ds_user_ptr = NULL;
 868                 }
 869                 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
 870                     dsl_dataset_destroy_sync, ds, da->dstg, 0);
 871         } else if (err == ENOENT) {
 872                 err = 0;
 873         } else {
 874                 (void) strcpy(da->failed, name);
 875         }
 876         return (err);
 877 }
 878
 879 /*
 880  * Destroy 'snapname' in all descendants of 'fsname'.
 881  */
 882 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
 883 int
 884 dsl_snapshots_destroy(char *fsname, char *snapname)
 885 {
 886         int err;
 887         struct destroyarg da;
 888         dsl_sync_task_t *dst;
 889         spa_t *spa;
 890
 891         err = spa_open(fsname, &spa, FTAG);
 892         if (err)
 893                 return (err);
 894         da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
 895         da.snapname = snapname;
 896         da.failed = fsname;
 897
 898         err = dmu_objset_find(fsname,
 899             dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
 900
 901         if (err == 0)
 902                 err = dsl_sync_task_group_wait(da.dstg);
 903
 904         for (dst = list_head(&da.dstg->dstg_tasks); dst;
 905             dst = list_next(&da.dstg->dstg_tasks, dst)) {
 906                 dsl_dataset_t *ds = dst->dst_arg1;
 907                 /*
 908                  * Return the file system name that triggered the error
 909                  */
 910                 if (dst->dst_err) {
 911                         dsl_dataset_name(ds, fsname);
 912                         *strchr(fsname, '@') = '\0';
 913                 }
 914                 dsl_dataset_disown(ds, da.dstg);
 915         }
 916
 917         dsl_sync_task_group_destroy(da.dstg);
 918         spa_close(spa, FTAG);
 919         return (err);
 920 }
 921
 922 /*
 923  * ds must be opened as OWNER.  On return (whether successful or not),
 924  * ds will be closed and caller can no longer dereference it.
 925  */
 926 int
 927 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag)
 928 {
 929         int err;
 930         dsl_sync_task_group_t *dstg;
 931         objset_t *os;
 932         dsl_dir_t *dd;
 933         uint64_t obj;
 934
 935         if (dsl_dataset_is_snapshot(ds)) {
 936                 /* Destroying a snapshot is simpler */
 937                 dsl_dataset_make_exclusive(ds, tag);
 938
 939                 if (ds->ds_user_ptr) {
 940                         ds->ds_user_evict_func(ds, ds->ds_user_ptr);
 941                         ds->ds_user_ptr = NULL;
 942                 }
 943                 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
 944                     dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
 945                     ds, tag, 0);
 946                 goto out;
 947         }
 948
 949         dd = ds->ds_dir;
 950
 951         /*
 952          * Check for errors and mark this ds as inconsistent, in
 953          * case we crash while freeing the objects.
 954          */
 955         err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
 956             dsl_dataset_destroy_begin_sync, ds, NULL, 0);
 957         if (err)
 958                 goto out;
 959
 960         err = dmu_objset_open_ds(ds, DMU_OST_ANY, &os);
 961         if (err)
 962                 goto out;
 963
 964         /*
 965          * remove the objects in open context, so that we won't
 966          * have too much to do in syncing context.
 967          */
 968         for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
 969             ds->ds_phys->ds_prev_snap_txg)) {
 970                 /*
 971                  * Ignore errors, if there is not enough disk space
 972                  * we will deal with it in dsl_dataset_destroy_sync().
 973                  */
 974                 (void) dmu_free_object(os, obj);
 975         }
 976
 977         dmu_objset_close(os);
 978         if (err != ESRCH)
 979                 goto out;
 980
 981         rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
 982         err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
 983         rw_exit(&dd->dd_pool->dp_config_rwlock);
 984
 985         if (err)
 986                 goto out;
 987
 988         if (ds->ds_user_ptr) {
 989                 /*
 990                  * We need to sync out all in-flight IO before we try
 991                  * to evict (the dataset evict func is trying to clear
 992                  * the cached entries for this dataset in the ARC).
 993                  */
 994                 txg_wait_synced(dd->dd_pool, 0);
 995         }
 996
 997         /*
 998          * Blow away the dsl_dir + head dataset.
 999          */
1000         dsl_dataset_make_exclusive(ds, tag);
1001         if (ds->ds_user_ptr) {
1002                 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
1003                 ds->ds_user_ptr = NULL;
1004         }
1005         dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1006         dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1007             dsl_dataset_destroy_sync, ds, tag, 0);
1008         dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1009             dsl_dir_destroy_sync, dd, FTAG, 0);
1010         err = dsl_sync_task_group_wait(dstg);
1011         dsl_sync_task_group_destroy(dstg);
1012         /* if it is successful, dsl_dir_destroy_sync will close the dd */
1013         if (err)
1014                 dsl_dir_close(dd, FTAG);
1015 out:
1016         dsl_dataset_disown(ds, tag);
1017         return (err);
1018 }
1019
1020 int
1021 dsl_dataset_rollback(dsl_dataset_t *ds, dmu_objset_type_t ost)
1022 {
1023         int err;
1024
1025         ASSERT(ds->ds_owner);
1026
1027         dsl_dataset_make_exclusive(ds, ds->ds_owner);
1028         err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1029             dsl_dataset_rollback_check, dsl_dataset_rollback_sync,
1030             ds, &ost, 0);
1031         /* drop exclusive access */
1032         mutex_enter(&ds->ds_lock);
1033         rw_exit(&ds->ds_rwlock);
1034         cv_broadcast(&ds->ds_exclusive_cv);
1035         mutex_exit(&ds->ds_lock);
1036         return (err);
1037 }
1038
1039 void *
1040 dsl_dataset_set_user_ptr(dsl_dataset_t *ds,
1041     void *p, dsl_dataset_evict_func_t func)
1042 {
1043         void *old;
1044
1045         mutex_enter(&ds->ds_lock);
1046         old = ds->ds_user_ptr;
1047         if (old == NULL) {
1048                 ds->ds_user_ptr = p;
1049                 ds->ds_user_evict_func = func;
1050         }
1051         mutex_exit(&ds->ds_lock);
1052         return (old);
1053 }
1054
1055 void *
1056 dsl_dataset_get_user_ptr(dsl_dataset_t *ds)
1057 {
1058         return (ds->ds_user_ptr);
1059 }
1060
1061
1062 blkptr_t *
1063 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1064 {
1065         return (&ds->ds_phys->ds_bp);
1066 }
1067
1068 void
1069 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1070 {
1071         ASSERT(dmu_tx_is_syncing(tx));
1072         /* If it's the meta-objset, set dp_meta_rootbp */
1073         if (ds == NULL) {
1074                 tx->tx_pool->dp_meta_rootbp = *bp;
1075         } else {
1076                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1077                 ds->ds_phys->ds_bp = *bp;
1078         }
1079 }
1080
1081 spa_t *
1082 dsl_dataset_get_spa(dsl_dataset_t *ds)
1083 {
1084         return (ds->ds_dir->dd_pool->dp_spa);
1085 }
1086
1087 void
1088 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1089 {
1090         dsl_pool_t *dp;
1091
1092         if (ds == NULL) /* this is the meta-objset */
1093                 return;
1094
1095         ASSERT(ds->ds_user_ptr != NULL);
1096
1097         if (ds->ds_phys->ds_next_snap_obj != 0)
1098                 panic("dirtying snapshot!");
1099
1100         dp = ds->ds_dir->dd_pool;
1101
1102         if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1103                 /* up the hold count until we can be written out */
1104                 dmu_buf_add_ref(ds->ds_dbuf, ds);
1105         }
1106 }
1107
1108 /*
1109  * The unique space in the head dataset can be calculated by subtracting
1110  * the space used in the most recent snapshot, that is still being used
1111  * in this file system, from the space currently in use.  To figure out
1112  * the space in the most recent snapshot still in use, we need to take
1113  * the total space used in the snapshot and subtract out the space that
1114  * has been freed up since the snapshot was taken.
1115  */
1116 static void
1117 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1118 {
1119         uint64_t mrs_used;
1120         uint64_t dlused, dlcomp, dluncomp;
1121
1122         ASSERT(ds->ds_object == ds->ds_dir->dd_phys->dd_head_dataset_obj);
1123
1124         if (ds->ds_phys->ds_prev_snap_obj != 0)
1125                 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1126         else
1127                 mrs_used = 0;
1128
1129         VERIFY(0 == bplist_space(&ds->ds_deadlist, &dlused, &dlcomp,
1130             &dluncomp));
1131
1132         ASSERT3U(dlused, <=, mrs_used);
1133         ds->ds_phys->ds_unique_bytes =
1134             ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1135
1136         if (!DS_UNIQUE_IS_ACCURATE(ds) &&
1137             spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1138             SPA_VERSION_UNIQUE_ACCURATE)
1139                 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1140 }
1141
1142 static uint64_t
1143 dsl_dataset_unique(dsl_dataset_t *ds)
1144 {
1145         if (!DS_UNIQUE_IS_ACCURATE(ds) && !dsl_dataset_is_snapshot(ds))
1146                 dsl_dataset_recalc_head_uniq(ds);
1147
1148         return (ds->ds_phys->ds_unique_bytes);
1149 }
1150
1151 struct killarg {
1152         dsl_dataset_t *ds;
1153         zio_t *zio;
1154         dmu_tx_t *tx;
1155 };
1156
1157 /* ARGSUSED */
1158 static int
1159 kill_blkptr(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb,
1160     const dnode_phys_t *dnp, void *arg)
1161 {
1162         struct killarg *ka = arg;
1163
1164         if (bp == NULL)
1165                 return (0);
1166
1167         ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1168         (void) dsl_dataset_block_kill(ka->ds, bp, ka->zio, ka->tx);
1169
1170         return (0);
1171 }
1172
1173 /* ARGSUSED */
1174 static int
1175 dsl_dataset_rollback_check(void *arg1, void *arg2, dmu_tx_t *tx)
1176 {
1177         dsl_dataset_t *ds = arg1;
1178         dmu_objset_type_t *ost = arg2;
1179
1180         /*
1181          * We can only roll back to emptyness if it is a ZPL objset.
1182          */
1183         if (*ost != DMU_OST_ZFS && ds->ds_phys->ds_prev_snap_txg == 0)
1184                 return (EINVAL);
1185
1186         /*
1187          * This must not be a snapshot.
1188          */
1189         if (ds->ds_phys->ds_next_snap_obj != 0)
1190                 return (EINVAL);
1191
1192         /*
1193          * If we made changes this txg, traverse_dataset won't find
1194          * them.  Try again.
1195          */
1196         if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1197                 return (EAGAIN);
1198
1199         return (0);
1200 }
1201
1202 /* ARGSUSED */
1203 static void
1204 dsl_dataset_rollback_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1205 {
1206         dsl_dataset_t *ds = arg1;
1207         dmu_objset_type_t *ost = arg2;
1208         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1209
1210         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1211
1212         /*
1213          * Before the roll back destroy the zil.
1214          */
1215         if (ds->ds_user_ptr != NULL) {
1216                 zil_rollback_destroy(
1217                     ((objset_impl_t *)ds->ds_user_ptr)->os_zil, tx);
1218
1219                 /*
1220                  * We need to make sure that the objset_impl_t is reopened after
1221                  * we do the rollback, otherwise it will have the wrong
1222                  * objset_phys_t.  Normally this would happen when this
1223                  * dataset-open is closed, thus causing the
1224                  * dataset to be immediately evicted.  But when doing "zfs recv
1225                  * -F", we reopen the objset before that, so that there is no
1226                  * window where the dataset is closed and inconsistent.
1227                  */
1228                 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
1229                 ds->ds_user_ptr = NULL;
1230         }
1231
1232         /* Transfer space that was freed since last snap back to the head. */
1233         {
1234                 uint64_t used;
1235
1236                 VERIFY(0 == bplist_space_birthrange(&ds->ds_deadlist,
1237                     ds->ds_origin_txg, UINT64_MAX, &used));
1238                 dsl_dir_transfer_space(ds->ds_dir, used,
1239                     DD_USED_SNAP, DD_USED_HEAD, tx);
1240         }
1241
1242         /* Zero out the deadlist. */
1243         bplist_close(&ds->ds_deadlist);
1244         bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx);
1245         ds->ds_phys->ds_deadlist_obj =
1246             bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
1247         VERIFY(0 == bplist_open(&ds->ds_deadlist, mos,
1248             ds->ds_phys->ds_deadlist_obj));
1249
1250         {
1251                 /* Free blkptrs that we gave birth to */
1252                 zio_t *zio;
1253                 struct killarg ka;
1254
1255                 zio = zio_root(tx->tx_pool->dp_spa, NULL, NULL,
1256                     ZIO_FLAG_MUSTSUCCEED);
1257                 ka.ds = ds;
1258                 ka.zio = zio;
1259                 ka.tx = tx;
1260                 (void) traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1261                     TRAVERSE_POST, kill_blkptr, &ka);
1262                 (void) zio_wait(zio);
1263         }
1264
1265         ASSERT(!(ds->ds_phys->ds_flags & DS_FLAG_UNIQUE_ACCURATE) ||
1266             ds->ds_phys->ds_unique_bytes == 0);
1267
1268         if (ds->ds_prev && ds->ds_prev != ds->ds_dir->dd_pool->dp_origin_snap) {
1269                 /* Change our contents to that of the prev snapshot */
1270
1271                 ASSERT3U(ds->ds_prev->ds_object, ==,
1272                     ds->ds_phys->ds_prev_snap_obj);
1273                 ASSERT3U(ds->ds_phys->ds_used_bytes, <=,
1274                     ds->ds_prev->ds_phys->ds_used_bytes);
1275
1276                 ds->ds_phys->ds_bp = ds->ds_prev->ds_phys->ds_bp;
1277                 ds->ds_phys->ds_used_bytes =
1278                     ds->ds_prev->ds_phys->ds_used_bytes;
1279                 ds->ds_phys->ds_compressed_bytes =
1280                     ds->ds_prev->ds_phys->ds_compressed_bytes;
1281                 ds->ds_phys->ds_uncompressed_bytes =
1282                     ds->ds_prev->ds_phys->ds_uncompressed_bytes;
1283                 ds->ds_phys->ds_flags = ds->ds_prev->ds_phys->ds_flags;
1284
1285                 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1286                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1287                         ds->ds_prev->ds_phys->ds_unique_bytes = 0;
1288                 }
1289         } else {
1290                 objset_impl_t *osi;
1291
1292                 ASSERT3U(ds->ds_phys->ds_used_bytes, ==, 0);
1293                 ASSERT3U(ds->ds_phys->ds_compressed_bytes, ==, 0);
1294                 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, ==, 0);
1295
1296                 bzero(&ds->ds_phys->ds_bp, sizeof (blkptr_t));
1297                 ds->ds_phys->ds_flags = 0;
1298                 ds->ds_phys->ds_unique_bytes = 0;
1299                 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1300                     SPA_VERSION_UNIQUE_ACCURATE)
1301                         ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1302
1303                 osi = dmu_objset_create_impl(ds->ds_dir->dd_pool->dp_spa, ds,
1304                     &ds->ds_phys->ds_bp, *ost, tx);
1305 #ifdef _KERNEL
1306                 zfs_create_fs(&osi->os, kcred, NULL, tx);
1307 #endif
1308         }
1309
1310         spa_history_internal_log(LOG_DS_ROLLBACK, ds->ds_dir->dd_pool->dp_spa,
1311             tx, cr, "dataset = %llu", ds->ds_object);
1312 }
1313
1314 /* ARGSUSED */
1315 static int
1316 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1317 {
1318         dsl_dataset_t *ds = arg1;
1319         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1320         uint64_t count;
1321         int err;
1322
1323         /*
1324          * Can't delete a head dataset if there are snapshots of it.
1325          * (Except if the only snapshots are from the branch we cloned
1326          * from.)
1327          */
1328         if (ds->ds_prev != NULL &&
1329             ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1330                 return (EINVAL);
1331
1332         /*
1333          * This is really a dsl_dir thing, but check it here so that
1334          * we'll be less likely to leave this dataset inconsistent &
1335          * nearly destroyed.
1336          */
1337         err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1338         if (err)
1339                 return (err);
1340         if (count != 0)
1341                 return (EEXIST);
1342
1343         return (0);
1344 }
1345
1346 /* ARGSUSED */
1347 static void
1348 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1349 {
1350         dsl_dataset_t *ds = arg1;
1351         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1352
1353         /* Mark it as inconsistent on-disk, in case we crash */
1354         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1355         ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1356
1357         spa_history_internal_log(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1358             cr, "dataset = %llu", ds->ds_object);
1359 }
1360
1361 /* ARGSUSED */
1362 int
1363 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1364 {
1365         dsl_dataset_t *ds = arg1;
1366
1367         /* we have an owner hold, so noone else can destroy us */
1368         ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1369
1370         /* Can't delete a branch point. */
1371         if (ds->ds_phys->ds_num_children > 1)
1372                 return (EEXIST);
1373
1374         /*
1375          * Can't delete a head dataset if there are snapshots of it.
1376          * (Except if the only snapshots are from the branch we cloned
1377          * from.)
1378          */
1379         if (ds->ds_prev != NULL &&
1380             ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1381                 return (EINVAL);
1382
1383         /*
1384          * If we made changes this txg, traverse_dsl_dataset won't find
1385          * them.  Try again.
1386          */
1387         if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1388                 return (EAGAIN);
1389
1390         /* XXX we should do some i/o error checking... */
1391         return (0);
1392 }
1393
1394 struct refsarg {
1395         kmutex_t lock;
1396         boolean_t gone;
1397         kcondvar_t cv;
1398 };
1399
1400 /* ARGSUSED */
1401 static void
1402 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1403 {
1404         struct refsarg *arg = argv;
1405
1406         mutex_enter(&arg->lock);
1407         arg->gone = TRUE;
1408         cv_signal(&arg->cv);
1409         mutex_exit(&arg->lock);
1410 }
1411
1412 static void
1413 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1414 {
1415         struct refsarg arg;
1416
1417         mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1418         cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1419         arg.gone = FALSE;
1420         (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1421             dsl_dataset_refs_gone);
1422         dmu_buf_rele(ds->ds_dbuf, tag);
1423         mutex_enter(&arg.lock);
1424         while (!arg.gone)
1425                 cv_wait(&arg.cv, &arg.lock);
1426         ASSERT(arg.gone);
1427         mutex_exit(&arg.lock);
1428         ds->ds_dbuf = NULL;
1429         ds->ds_phys = NULL;
1430         mutex_destroy(&arg.lock);
1431         cv_destroy(&arg.cv);
1432 }
1433
1434 void
1435 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx)
1436 {
1437         dsl_dataset_t *ds = arg1;
1438         zio_t *zio;
1439         int err;
1440         int after_branch_point = FALSE;
1441         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1442         objset_t *mos = dp->dp_meta_objset;
1443         dsl_dataset_t *ds_prev = NULL;
1444         uint64_t obj;
1445
1446         ASSERT(ds->ds_owner);
1447         ASSERT3U(ds->ds_phys->ds_num_children, <=, 1);
1448         ASSERT(ds->ds_prev == NULL ||
1449             ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1450         ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1451
1452         /* signal any waiters that this dataset is going away */
1453         mutex_enter(&ds->ds_lock);
1454         ds->ds_owner = dsl_reaper;
1455         cv_broadcast(&ds->ds_exclusive_cv);
1456         mutex_exit(&ds->ds_lock);
1457
1458         /* Remove our reservation */
1459         if (ds->ds_reserved != 0) {
1460                 uint64_t val = 0;
1461                 dsl_dataset_set_reservation_sync(ds, &val, cr, tx);
1462                 ASSERT3U(ds->ds_reserved, ==, 0);
1463         }
1464
1465         ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1466
1467         dsl_pool_ds_destroyed(ds, tx);
1468
1469         obj = ds->ds_object;
1470
1471         if (ds->ds_phys->ds_prev_snap_obj != 0) {
1472                 if (ds->ds_prev) {
1473                         ds_prev = ds->ds_prev;
1474                 } else {
1475                         VERIFY(0 == dsl_dataset_hold_obj(dp,
1476                             ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1477                 }
1478                 after_branch_point =
1479                     (ds_prev->ds_phys->ds_next_snap_obj != obj);
1480
1481                 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1482                 if (after_branch_point &&
1483                     ds_prev->ds_phys->ds_next_clones_obj != 0) {
1484                         VERIFY(0 == zap_remove_int(mos,
1485                             ds_prev->ds_phys->ds_next_clones_obj, obj, tx));
1486                         if (ds->ds_phys->ds_next_snap_obj != 0) {
1487                                 VERIFY(0 == zap_add_int(mos,
1488                                     ds_prev->ds_phys->ds_next_clones_obj,
1489                                     ds->ds_phys->ds_next_snap_obj, tx));
1490                         }
1491                 }
1492                 if (after_branch_point &&
1493                     ds->ds_phys->ds_next_snap_obj == 0) {
1494                         /* This clone is toast. */
1495                         ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1496                         ds_prev->ds_phys->ds_num_children--;
1497                 } else if (!after_branch_point) {
1498                         ds_prev->ds_phys->ds_next_snap_obj =
1499                             ds->ds_phys->ds_next_snap_obj;
1500                 }
1501         }
1502
1503         zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1504
1505         if (ds->ds_phys->ds_next_snap_obj != 0) {
1506                 blkptr_t bp;
1507                 dsl_dataset_t *ds_next;
1508                 uint64_t itor = 0;
1509                 uint64_t old_unique;
1510                 int64_t used = 0, compressed = 0, uncompressed = 0;
1511
1512                 VERIFY(0 == dsl_dataset_hold_obj(dp,
1513                     ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1514                 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1515
1516                 old_unique = dsl_dataset_unique(ds_next);
1517
1518                 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1519                 ds_next->ds_phys->ds_prev_snap_obj =
1520                     ds->ds_phys->ds_prev_snap_obj;
1521                 ds_next->ds_phys->ds_prev_snap_txg =
1522                     ds->ds_phys->ds_prev_snap_txg;
1523                 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1524                     ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1525
1526                 /*
1527                  * Transfer to our deadlist (which will become next's
1528                  * new deadlist) any entries from next's current
1529                  * deadlist which were born before prev, and free the
1530                  * other entries.
1531                  *
1532                  * XXX we're doing this long task with the config lock held
1533                  */
1534                 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) {
1535                         if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) {
1536                                 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist,
1537                                     &bp, tx));
1538                                 if (ds_prev && !after_branch_point &&
1539                                     bp.blk_birth >
1540                                     ds_prev->ds_phys->ds_prev_snap_txg) {
1541                                         ds_prev->ds_phys->ds_unique_bytes +=
1542                                             bp_get_dasize(dp->dp_spa, &bp);
1543                                 }
1544                         } else {
1545                                 used += bp_get_dasize(dp->dp_spa, &bp);
1546                                 compressed += BP_GET_PSIZE(&bp);
1547                                 uncompressed += BP_GET_UCSIZE(&bp);
1548                                 /* XXX check return value? */
1549                                 (void) dsl_free(zio, dp, tx->tx_txg,
1550                                     &bp, NULL, NULL, ARC_NOWAIT);
1551                         }
1552                 }
1553
1554                 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes);
1555
1556                 /* change snapused */
1557                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1558                     -used, -compressed, -uncompressed, tx);
1559
1560                 /* free next's deadlist */
1561                 bplist_close(&ds_next->ds_deadlist);
1562                 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx);
1563
1564                 /* set next's deadlist to our deadlist */
1565                 bplist_close(&ds->ds_deadlist);
1566                 ds_next->ds_phys->ds_deadlist_obj =
1567                     ds->ds_phys->ds_deadlist_obj;
1568                 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos,
1569                     ds_next->ds_phys->ds_deadlist_obj));
1570                 ds->ds_phys->ds_deadlist_obj = 0;
1571
1572                 if (ds_next->ds_phys->ds_next_snap_obj != 0) {
1573                         /*
1574                          * Update next's unique to include blocks which
1575                          * were previously shared by only this snapshot
1576                          * and it.  Those blocks will be born after the
1577                          * prev snap and before this snap, and will have
1578                          * died after the next snap and before the one
1579                          * after that (ie. be on the snap after next's
1580                          * deadlist).
1581                          *
1582                          * XXX we're doing this long task with the
1583                          * config lock held
1584                          */
1585                         dsl_dataset_t *ds_after_next;
1586                         uint64_t space;
1587
1588                         VERIFY(0 == dsl_dataset_hold_obj(dp,
1589                             ds_next->ds_phys->ds_next_snap_obj,
1590                             FTAG, &ds_after_next));
1591
1592                         VERIFY(0 ==
1593                             bplist_space_birthrange(&ds_after_next->ds_deadlist,
1594                             ds->ds_phys->ds_prev_snap_txg,
1595                             ds->ds_phys->ds_creation_txg, &space));
1596                         ds_next->ds_phys->ds_unique_bytes += space;
1597
1598                         dsl_dataset_rele(ds_after_next, FTAG);
1599                         ASSERT3P(ds_next->ds_prev, ==, NULL);
1600                 } else {
1601                         ASSERT3P(ds_next->ds_prev, ==, ds);
1602                         dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1603                         ds_next->ds_prev = NULL;
1604                         if (ds_prev) {
1605                                 VERIFY(0 == dsl_dataset_get_ref(dp,
1606                                     ds->ds_phys->ds_prev_snap_obj,
1607                                     ds_next, &ds_next->ds_prev));
1608                         }
1609
1610                         dsl_dataset_recalc_head_uniq(ds_next);
1611
1612                         /*
1613                          * Reduce the amount of our unconsmed refreservation
1614                          * being charged to our parent by the amount of
1615                          * new unique data we have gained.
1616                          */
1617                         if (old_unique < ds_next->ds_reserved) {
1618                                 int64_t mrsdelta;
1619                                 uint64_t new_unique =
1620                                     ds_next->ds_phys->ds_unique_bytes;
1621
1622                                 ASSERT(old_unique <= new_unique);
1623                                 mrsdelta = MIN(new_unique - old_unique,
1624                                     ds_next->ds_reserved - old_unique);
1625                                 dsl_dir_diduse_space(ds->ds_dir,
1626                                     DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1627                         }
1628                 }
1629                 dsl_dataset_rele(ds_next, FTAG);
1630         } else {
1631                 /*
1632                  * There's no next snapshot, so this is a head dataset.
1633                  * Destroy the deadlist.  Unless it's a clone, the
1634                  * deadlist should be empty.  (If it's a clone, it's
1635                  * safe to ignore the deadlist contents.)
1636                  */
1637                 struct killarg ka;
1638
1639                 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist));
1640                 bplist_close(&ds->ds_deadlist);
1641                 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx);
1642                 ds->ds_phys->ds_deadlist_obj = 0;
1643
1644                 /*
1645                  * Free everything that we point to (that's born after
1646                  * the previous snapshot, if we are a clone)
1647                  *
1648                  * NB: this should be very quick, because we already
1649                  * freed all the objects in open context.
1650                  */
1651                 ka.ds = ds;
1652                 ka.zio = zio;
1653                 ka.tx = tx;
1654                 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1655                     TRAVERSE_POST, kill_blkptr, &ka);
1656                 ASSERT3U(err, ==, 0);
1657                 ASSERT(spa_version(dp->dp_spa) < SPA_VERSION_UNIQUE_ACCURATE ||
1658                     ds->ds_phys->ds_unique_bytes == 0);
1659         }
1660
1661         err = zio_wait(zio);
1662         ASSERT3U(err, ==, 0);
1663
1664         if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1665                 /* Erase the link in the dir */
1666                 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1667                 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1668                 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1669                 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1670                 ASSERT(err == 0);
1671         } else {
1672                 /* remove from snapshot namespace */
1673                 dsl_dataset_t *ds_head;
1674                 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1675                 VERIFY(0 == dsl_dataset_hold_obj(dp,
1676                     ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1677                 VERIFY(0 == dsl_dataset_get_snapname(ds));
1678 #ifdef ZFS_DEBUG
1679                 {
1680                         uint64_t val;
1681
1682                         err = dsl_dataset_snap_lookup(ds_head,
1683                             ds->ds_snapname, &val);
1684                         ASSERT3U(err, ==, 0);
1685                         ASSERT3U(val, ==, obj);
1686                 }
1687 #endif
1688                 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1689                 ASSERT(err == 0);
1690                 dsl_dataset_rele(ds_head, FTAG);
1691         }
1692
1693         if (ds_prev && ds->ds_prev != ds_prev)
1694                 dsl_dataset_rele(ds_prev, FTAG);
1695
1696         spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1697         spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx,
1698             cr, "dataset = %llu", ds->ds_object);
1699
1700         if (ds->ds_phys->ds_next_clones_obj != 0) {
1701                 uint64_t count;
1702                 ASSERT(0 == zap_count(mos,
1703                     ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1704                 VERIFY(0 == dmu_object_free(mos,
1705                     ds->ds_phys->ds_next_clones_obj, tx));
1706         }
1707         if (ds->ds_phys->ds_props_obj != 0)
1708                 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1709         dsl_dir_close(ds->ds_dir, ds);
1710         ds->ds_dir = NULL;
1711         dsl_dataset_drain_refs(ds, tag);
1712         VERIFY(0 == dmu_object_free(mos, obj, tx));
1713 }
1714
1715 static int
1716 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1717 {
1718         uint64_t asize;
1719
1720         if (!dmu_tx_is_syncing(tx))
1721                 return (0);
1722
1723         /*
1724          * If there's an fs-only reservation, any blocks that might become
1725          * owned by the snapshot dataset must be accommodated by space
1726          * outside of the reservation.
1727          */
1728         asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved);
1729         if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE))
1730                 return (ENOSPC);
1731
1732         /*
1733          * Propogate any reserved space for this snapshot to other
1734          * snapshot checks in this sync group.
1735          */
1736         if (asize > 0)
1737                 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1738
1739         return (0);
1740 }
1741
1742 /* ARGSUSED */
1743 int
1744 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1745 {
1746         dsl_dataset_t *ds = arg1;
1747         const char *snapname = arg2;
1748         int err;
1749         uint64_t value;
1750
1751         /*
1752          * We don't allow multiple snapshots of the same txg.  If there
1753          * is already one, try again.
1754          */
1755         if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1756                 return (EAGAIN);
1757
1758         /*
1759          * Check for conflicting name snapshot name.
1760          */
1761         err = dsl_dataset_snap_lookup(ds, snapname, &value);
1762         if (err == 0)
1763                 return (EEXIST);
1764         if (err != ENOENT)
1765                 return (err);
1766
1767         /*
1768          * Check that the dataset's name is not too long.  Name consists
1769          * of the dataset's length + 1 for the @-sign + snapshot name's length
1770          */
1771         if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
1772                 return (ENAMETOOLONG);
1773
1774         err = dsl_dataset_snapshot_reserve_space(ds, tx);
1775         if (err)
1776                 return (err);
1777
1778         ds->ds_trysnap_txg = tx->tx_txg;
1779         return (0);
1780 }
1781
1782 void
1783 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1784 {
1785         dsl_dataset_t *ds = arg1;
1786         const char *snapname = arg2;
1787         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1788         dmu_buf_t *dbuf;
1789         dsl_dataset_phys_t *dsphys;
1790         uint64_t dsobj, crtxg;
1791         objset_t *mos = dp->dp_meta_objset;
1792         int err;
1793
1794         ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1795
1796         /*
1797          * The origin's ds_creation_txg has to be < TXG_INITIAL
1798          */
1799         if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1800                 crtxg = 1;
1801         else
1802                 crtxg = tx->tx_txg;
1803
1804         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1805             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1806         VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1807         dmu_buf_will_dirty(dbuf, tx);
1808         dsphys = dbuf->db_data;
1809         bzero(dsphys, sizeof (dsl_dataset_phys_t));
1810         dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1811         dsphys->ds_fsid_guid = unique_create();
1812         (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1813             sizeof (dsphys->ds_guid));
1814         dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
1815         dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
1816         dsphys->ds_next_snap_obj = ds->ds_object;
1817         dsphys->ds_num_children = 1;
1818         dsphys->ds_creation_time = gethrestime_sec();
1819         dsphys->ds_creation_txg = crtxg;
1820         dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
1821         dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
1822         dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
1823         dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
1824         dsphys->ds_flags = ds->ds_phys->ds_flags;
1825         dsphys->ds_bp = ds->ds_phys->ds_bp;
1826         dmu_buf_rele(dbuf, FTAG);
1827
1828         ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
1829         if (ds->ds_prev) {
1830                 uint64_t next_clones_obj =
1831                     ds->ds_prev->ds_phys->ds_next_clones_obj;
1832                 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
1833                     ds->ds_object ||
1834                     ds->ds_prev->ds_phys->ds_num_children > 1);
1835                 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1836                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1837                         ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1838                             ds->ds_prev->ds_phys->ds_creation_txg);
1839                         ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
1840                 } else if (next_clones_obj != 0) {
1841                         VERIFY3U(0, ==, zap_remove_int(mos,
1842                             next_clones_obj, dsphys->ds_next_snap_obj, tx));
1843                         VERIFY3U(0, ==, zap_add_int(mos,
1844                             next_clones_obj, dsobj, tx));
1845                 }
1846         }
1847
1848         /*
1849          * If we have a reference-reservation on this dataset, we will
1850          * need to increase the amount of refreservation being charged
1851          * since our unique space is going to zero.
1852          */
1853         if (ds->ds_reserved) {
1854                 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved);
1855                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1856                     add, 0, 0, tx);
1857         }
1858
1859         bplist_close(&ds->ds_deadlist);
1860         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1861         ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
1862         ds->ds_phys->ds_prev_snap_obj = dsobj;
1863         ds->ds_phys->ds_prev_snap_txg = crtxg;
1864         ds->ds_phys->ds_unique_bytes = 0;
1865         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1866                 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1867         ds->ds_phys->ds_deadlist_obj =
1868             bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
1869         VERIFY(0 == bplist_open(&ds->ds_deadlist, mos,
1870             ds->ds_phys->ds_deadlist_obj));
1871
1872         dprintf("snap '%s' -> obj %llu\n", snapname, dsobj);
1873         err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
1874             snapname, 8, 1, &dsobj, tx);
1875         ASSERT(err == 0);
1876
1877         if (ds->ds_prev)
1878                 dsl_dataset_drop_ref(ds->ds_prev, ds);
1879         VERIFY(0 == dsl_dataset_get_ref(dp,
1880             ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
1881
1882         dsl_pool_ds_snapshotted(ds, tx);
1883
1884         spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr,
1885             "dataset = %llu", dsobj);
1886 }
1887
1888 void
1889 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1890 {
1891         ASSERT(dmu_tx_is_syncing(tx));
1892         ASSERT(ds->ds_user_ptr != NULL);
1893         ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
1894
1895         /*
1896          * in case we had to change ds_fsid_guid when we opened it,
1897          * sync it out now.
1898          */
1899         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1900         ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
1901
1902         dsl_dir_dirty(ds->ds_dir, tx);
1903         dmu_objset_sync(ds->ds_user_ptr, zio, tx);
1904 }
1905
1906 void
1907 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1908 {
1909         uint64_t refd, avail, uobjs, aobjs;
1910
1911         dsl_dir_stats(ds->ds_dir, nv);
1912
1913         dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1914         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1915         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1916
1917         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1918             ds->ds_phys->ds_creation_time);
1919         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1920             ds->ds_phys->ds_creation_txg);
1921         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1922             ds->ds_quota);
1923         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1924             ds->ds_reserved);
1925         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1926             ds->ds_phys->ds_guid);
1927
1928         if (ds->ds_phys->ds_next_snap_obj) {
1929                 /*
1930                  * This is a snapshot; override the dd's space used with
1931                  * our unique space and compression ratio.
1932                  */
1933                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1934                     ds->ds_phys->ds_unique_bytes);
1935                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
1936                     ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
1937                     (ds->ds_phys->ds_uncompressed_bytes * 100 /
1938                     ds->ds_phys->ds_compressed_bytes));
1939         }
1940 }
1941
1942 void
1943 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
1944 {
1945         stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
1946         stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
1947         stat->dds_guid = ds->ds_phys->ds_guid;
1948         if (ds->ds_phys->ds_next_snap_obj) {
1949                 stat->dds_is_snapshot = B_TRUE;
1950                 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
1951         } else {
1952                 stat->dds_is_snapshot = B_FALSE;
1953                 stat->dds_num_clones = 0;
1954         }
1955
1956         /* clone origin is really a dsl_dir thing... */
1957         rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
1958         if (dsl_dir_is_clone(ds->ds_dir)) {
1959                 dsl_dataset_t *ods;
1960
1961                 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
1962                     ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
1963                 dsl_dataset_name(ods, stat->dds_origin);
1964                 dsl_dataset_drop_ref(ods, FTAG);
1965         } else {
1966                 stat->dds_origin[0] = '\0';
1967         }
1968         rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
1969 }
1970
1971 uint64_t
1972 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
1973 {
1974         return (ds->ds_fsid_guid);
1975 }
1976
1977 void
1978 dsl_dataset_space(dsl_dataset_t *ds,
1979     uint64_t *refdbytesp, uint64_t *availbytesp,
1980     uint64_t *usedobjsp, uint64_t *availobjsp)
1981 {
1982         *refdbytesp = ds->ds_phys->ds_used_bytes;
1983         *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
1984         if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
1985                 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
1986         if (ds->ds_quota != 0) {
1987                 /*
1988                  * Adjust available bytes according to refquota
1989                  */
1990                 if (*refdbytesp < ds->ds_quota)
1991                         *availbytesp = MIN(*availbytesp,
1992                             ds->ds_quota - *refdbytesp);
1993                 else
1994                         *availbytesp = 0;
1995         }
1996         *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
1997         *availobjsp = DN_MAX_OBJECT - *usedobjsp;
1998 }
1999
2000 boolean_t
2001 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2002 {
2003         dsl_pool_t *dp = ds->ds_dir->dd_pool;
2004
2005         ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2006             dsl_pool_sync_context(dp));
2007         if (ds->ds_prev == NULL)
2008                 return (B_FALSE);
2009         if (ds->ds_phys->ds_bp.blk_birth >
2010             ds->ds_prev->ds_phys->ds_creation_txg)
2011                 return (B_TRUE);
2012         return (B_FALSE);
2013 }
2014
2015 /* ARGSUSED */
2016 static int
2017 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2018 {
2019         dsl_dataset_t *ds = arg1;
2020         char *newsnapname = arg2;
2021         dsl_dir_t *dd = ds->ds_dir;
2022         dsl_dataset_t *hds;
2023         uint64_t val;
2024         int err;
2025
2026         err = dsl_dataset_hold_obj(dd->dd_pool,
2027             dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2028         if (err)
2029                 return (err);
2030
2031         /* new name better not be in use */
2032         err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2033         dsl_dataset_rele(hds, FTAG);
2034
2035         if (err == 0)
2036                 err = EEXIST;
2037         else if (err == ENOENT)
2038                 err = 0;
2039
2040         /* dataset name + 1 for the "@" + the new snapshot name must fit */
2041         if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2042                 err = ENAMETOOLONG;
2043
2044         return (err);
2045 }
2046
2047 static void
2048 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2,
2049     cred_t *cr, dmu_tx_t *tx)
2050 {
2051         dsl_dataset_t *ds = arg1;
2052         const char *newsnapname = arg2;
2053         dsl_dir_t *dd = ds->ds_dir;
2054         objset_t *mos = dd->dd_pool->dp_meta_objset;
2055         dsl_dataset_t *hds;
2056         int err;
2057
2058         ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2059
2060         VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2061             dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2062
2063         VERIFY(0 == dsl_dataset_get_snapname(ds));
2064         err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2065         ASSERT3U(err, ==, 0);
2066         mutex_enter(&ds->ds_lock);
2067         (void) strcpy(ds->ds_snapname, newsnapname);
2068         mutex_exit(&ds->ds_lock);
2069         err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2070             ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2071         ASSERT3U(err, ==, 0);
2072
2073         spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2074             cr, "dataset = %llu", ds->ds_object);
2075         dsl_dataset_rele(hds, FTAG);
2076 }
2077
2078 struct renamesnaparg {
2079         dsl_sync_task_group_t *dstg;
2080         char failed[MAXPATHLEN];
2081         char *oldsnap;
2082         char *newsnap;
2083 };
2084
2085 static int
2086 dsl_snapshot_rename_one(char *name, void *arg)
2087 {
2088         struct renamesnaparg *ra = arg;
2089         dsl_dataset_t *ds = NULL;
2090         char *cp;
2091         int err;
2092
2093         cp = name + strlen(name);
2094         *cp = '@';
2095         (void) strcpy(cp + 1, ra->oldsnap);
2096
2097         /*
2098          * For recursive snapshot renames the parent won't be changing
2099          * so we just pass name for both the to/from argument.
2100          */
2101         err = zfs_secpolicy_rename_perms(name, name, CRED());
2102         if (err == ENOENT) {
2103                 return (0);
2104         } else if (err) {
2105                 (void) strcpy(ra->failed, name);
2106                 return (err);
2107         }
2108
2109 #ifdef _KERNEL
2110         /*
2111          * For all filesystems undergoing rename, we'll need to unmount it.
2112          */
2113         (void) zfs_unmount_snap(name, NULL);
2114 #endif
2115         err = dsl_dataset_hold(name, ra->dstg, &ds);
2116         *cp = '\0';
2117         if (err == ENOENT) {
2118                 return (0);
2119         } else if (err) {
2120                 (void) strcpy(ra->failed, name);
2121                 return (err);
2122         }
2123
2124         dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2125             dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2126
2127         return (0);
2128 }
2129
2130 static int
2131 dsl_recursive_rename(char *oldname, const char *newname)
2132 {
2133         int err;
2134         struct renamesnaparg *ra;
2135         dsl_sync_task_t *dst;
2136         spa_t *spa;
2137         char *cp, *fsname = spa_strdup(oldname);
2138         int len = strlen(oldname);
2139
2140         /* truncate the snapshot name to get the fsname */
2141         cp = strchr(fsname, '@');
2142         *cp = '\0';
2143
2144         err = spa_open(fsname, &spa, FTAG);
2145         if (err) {
2146                 kmem_free(fsname, len + 1);
2147                 return (err);
2148         }
2149         ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2150         ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2151
2152         ra->oldsnap = strchr(oldname, '@') + 1;
2153         ra->newsnap = strchr(newname, '@') + 1;
2154         *ra->failed = '\0';
2155
2156         err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2157             DS_FIND_CHILDREN);
2158         kmem_free(fsname, len + 1);
2159
2160         if (err == 0) {
2161                 err = dsl_sync_task_group_wait(ra->dstg);
2162         }
2163
2164         for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2165             dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2166                 dsl_dataset_t *ds = dst->dst_arg1;
2167                 if (dst->dst_err) {
2168                         dsl_dir_name(ds->ds_dir, ra->failed);
2169                         (void) strcat(ra->failed, "@");
2170                         (void) strcat(ra->failed, ra->newsnap);
2171                 }
2172                 dsl_dataset_rele(ds, ra->dstg);
2173         }
2174
2175         if (err)
2176                 (void) strcpy(oldname, ra->failed);
2177
2178         dsl_sync_task_group_destroy(ra->dstg);
2179         kmem_free(ra, sizeof (struct renamesnaparg));
2180         spa_close(spa, FTAG);
2181         return (err);
2182 }
2183
2184 static int
2185 dsl_valid_rename(char *oldname, void *arg)
2186 {
2187         int delta = *(int *)arg;
2188
2189         if (strlen(oldname) + delta >= MAXNAMELEN)
2190                 return (ENAMETOOLONG);
2191
2192         return (0);
2193 }
2194
2195 #pragma weak dmu_objset_rename = dsl_dataset_rename
2196 int
2197 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2198 {
2199         dsl_dir_t *dd;
2200         dsl_dataset_t *ds;
2201         const char *tail;
2202         int err;
2203
2204         err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2205         if (err)
2206                 return (err);
2207         /*
2208          * If there are more than 2 references there may be holds
2209          * hanging around that haven't been cleared out yet.
2210          */
2211         if (dmu_buf_refcount(dd->dd_dbuf) > 2)
2212                 txg_wait_synced(dd->dd_pool, 0);
2213         if (tail == NULL) {
2214                 int delta = strlen(newname) - strlen(oldname);
2215
2216                 /* if we're growing, validate child name lengths */
2217                 if (delta > 0)
2218                         err = dmu_objset_find(oldname, dsl_valid_rename,
2219                             &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2220
2221                 if (!err)
2222                         err = dsl_dir_rename(dd, newname);
2223                 dsl_dir_close(dd, FTAG);
2224                 return (err);
2225         }
2226         if (tail[0] != '@') {
2227                 /* the name ended in a nonexistant component */
2228                 dsl_dir_close(dd, FTAG);
2229                 return (ENOENT);
2230         }
2231
2232         dsl_dir_close(dd, FTAG);
2233
2234         /* new name must be snapshot in same filesystem */
2235         tail = strchr(newname, '@');
2236         if (tail == NULL)
2237                 return (EINVAL);
2238         tail++;
2239         if (strncmp(oldname, newname, tail - newname) != 0)
2240                 return (EXDEV);
2241
2242         if (recursive) {
2243                 err = dsl_recursive_rename(oldname, newname);
2244         } else {
2245                 err = dsl_dataset_hold(oldname, FTAG, &ds);
2246                 if (err)
2247                         return (err);
2248
2249                 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2250                     dsl_dataset_snapshot_rename_check,
2251                     dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2252
2253                 dsl_dataset_rele(ds, FTAG);
2254         }
2255
2256         return (err);
2257 }
2258
2259 struct promotenode {
2260         list_node_t link;
2261         dsl_dataset_t *ds;
2262 };
2263
2264 struct promotearg {
2265         list_t shared_snaps, origin_snaps, clone_snaps;
2266         dsl_dataset_t *origin_origin, *origin_head;
2267         uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2268 };
2269
2270 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2271
2272 /* ARGSUSED */
2273 static int
2274 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2275 {
2276         dsl_dataset_t *hds = arg1;
2277         struct promotearg *pa = arg2;
2278         struct promotenode *snap = list_head(&pa->shared_snaps);
2279         dsl_dataset_t *origin_ds = snap->ds;
2280         int err;
2281
2282         /* Check that it is a real clone */
2283         if (!dsl_dir_is_clone(hds->ds_dir))
2284                 return (EINVAL);
2285
2286         /* Since this is so expensive, don't do the preliminary check */
2287         if (!dmu_tx_is_syncing(tx))
2288                 return (0);
2289
2290         if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2291                 return (EXDEV);
2292
2293         /* compute origin's new unique space */
2294         snap = list_tail(&pa->clone_snaps);
2295         ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2296         err = bplist_space_birthrange(&snap->ds->ds_deadlist,
2297             origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique);
2298         if (err)
2299                 return (err);
2300
2301         /*
2302          * Walk the snapshots that we are moving
2303          *
2304          * Compute space to transfer.  Consider the incremental changes
2305          * to used for each snapshot:
2306          * (my used) = (prev's used) + (blocks born) - (blocks killed)
2307          * So each snapshot gave birth to:
2308          * (blocks born) = (my used) - (prev's used) + (blocks killed)
2309          * So a sequence would look like:
2310          * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2311          * Which simplifies to:
2312          * uN + kN + kN-1 + ... + k1 + k0
2313          * Note however, if we stop before we reach the ORIGIN we get:
2314          * uN + kN + kN-1 + ... + kM - uM-1
2315          */
2316         pa->used = origin_ds->ds_phys->ds_used_bytes;
2317         pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2318         pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2319         for (snap = list_head(&pa->shared_snaps); snap;
2320             snap = list_next(&pa->shared_snaps, snap)) {
2321                 uint64_t val, dlused, dlcomp, dluncomp;
2322                 dsl_dataset_t *ds = snap->ds;
2323
2324                 /* Check that the snapshot name does not conflict */
2325                 VERIFY(0 == dsl_dataset_get_snapname(ds));
2326                 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2327                 if (err == 0)
2328                         return (EEXIST);
2329                 if (err != ENOENT)
2330                         return (err);
2331
2332                 /* The very first snapshot does not have a deadlist */
2333                 if (ds->ds_phys->ds_prev_snap_obj == 0)
2334                         continue;
2335
2336                 if (err = bplist_space(&ds->ds_deadlist,
2337                     &dlused, &dlcomp, &dluncomp))
2338                         return (err);
2339                 pa->used += dlused;
2340                 pa->comp += dlcomp;
2341                 pa->uncomp += dluncomp;
2342         }
2343
2344         /*
2345          * If we are a clone of a clone then we never reached ORIGIN,
2346          * so we need to subtract out the clone origin's used space.
2347          */
2348         if (pa->origin_origin) {
2349                 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2350                 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2351                 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2352         }
2353
2354         /* Check that there is enough space here */
2355         err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2356             pa->used);
2357         if (err)
2358                 return (err);
2359
2360         /*
2361          * Compute the amounts of space that will be used by snapshots
2362          * after the promotion (for both origin and clone).  For each,
2363          * it is the amount of space that will be on all of their
2364          * deadlists (that was not born before their new origin).
2365          */
2366         if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2367                 uint64_t space;
2368
2369                 /*
2370                  * Note, typically this will not be a clone of a clone,
2371                  * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so
2372                  * these snaplist_space() -> bplist_space_birthrange()
2373                  * calls will be fast because they do not have to
2374                  * iterate over all bps.
2375                  */
2376                 snap = list_head(&pa->origin_snaps);
2377                 err = snaplist_space(&pa->shared_snaps,
2378                     snap->ds->ds_origin_txg, &pa->cloneusedsnap);
2379                 if (err)
2380                         return (err);
2381
2382                 err = snaplist_space(&pa->clone_snaps,
2383                     snap->ds->ds_origin_txg, &space);
2384                 if (err)
2385                         return (err);
2386                 pa->cloneusedsnap += space;
2387         }
2388         if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2389                 err = snaplist_space(&pa->origin_snaps,
2390                     origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2391                 if (err)
2392                         return (err);
2393         }
2394
2395         return (0);
2396 }
2397
2398 static void
2399 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
2400 {
2401         dsl_dataset_t *hds = arg1;
2402         struct promotearg *pa = arg2;
2403         struct promotenode *snap = list_head(&pa->shared_snaps);
2404         dsl_dataset_t *origin_ds = snap->ds;
2405         dsl_dataset_t *origin_head;
2406         dsl_dir_t *dd = hds->ds_dir;
2407         dsl_pool_t *dp = hds->ds_dir->dd_pool;
2408         dsl_dir_t *odd = NULL;
2409         uint64_t oldnext_obj;
2410         int64_t delta;
2411
2412         ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2413
2414         snap = list_head(&pa->origin_snaps);
2415         origin_head = snap->ds;
2416
2417         /*
2418          * We need to explicitly open odd, since origin_ds's dd will be
2419          * changing.
2420          */
2421         VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2422             NULL, FTAG, &odd));
2423
2424         /* change origin's next snap */
2425         dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2426         oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2427         snap = list_tail(&pa->clone_snaps);
2428         ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2429         origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2430
2431         /* change the origin's next clone */
2432         if (origin_ds->ds_phys->ds_next_clones_obj) {
2433                 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2434                     origin_ds->ds_phys->ds_next_clones_obj,
2435                     origin_ds->ds_phys->ds_next_snap_obj, tx));
2436                 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2437                     origin_ds->ds_phys->ds_next_clones_obj,
2438                     oldnext_obj, tx));
2439         }
2440
2441         /* change origin */
2442         dmu_buf_will_dirty(dd->dd_dbuf, tx);
2443         ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2444         dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2445         hds->ds_origin_txg = origin_head->ds_origin_txg;
2446         dmu_buf_will_dirty(odd->dd_dbuf, tx);
2447         odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2448         origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg;
2449
2450         /* move snapshots to this dir */
2451         for (snap = list_head(&pa->shared_snaps); snap;
2452             snap = list_next(&pa->shared_snaps, snap)) {
2453                 dsl_dataset_t *ds = snap->ds;
2454
2455                 /* unregister props as dsl_dir is changing */
2456                 if (ds->ds_user_ptr) {
2457                         ds->ds_user_evict_func(ds, ds->ds_user_ptr);
2458                         ds->ds_user_ptr = NULL;
2459                 }
2460                 /* move snap name entry */
2461                 VERIFY(0 == dsl_dataset_get_snapname(ds));
2462                 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2463                     ds->ds_snapname, tx));
2464                 VERIFY(0 == zap_add(dp->dp_meta_objset,
2465                     hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2466                     8, 1, &ds->ds_object, tx));
2467                 /* change containing dsl_dir */
2468                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2469                 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2470                 ds->ds_phys->ds_dir_obj = dd->dd_object;
2471                 ASSERT3P(ds->ds_dir, ==, odd);
2472                 dsl_dir_close(ds->ds_dir, ds);
2473                 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2474                     NULL, ds, &ds->ds_dir));
2475
2476                 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2477         }
2478
2479         /*
2480          * Change space accounting.
2481          * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2482          * both be valid, or both be 0 (resulting in delta == 0).  This
2483          * is true for each of {clone,origin} independently.
2484          */
2485
2486         delta = pa->cloneusedsnap -
2487             dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2488         ASSERT3S(delta, >=, 0);
2489         ASSERT3U(pa->used, >=, delta);
2490         dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2491         dsl_dir_diduse_space(dd, DD_USED_HEAD,
2492             pa->used - delta, pa->comp, pa->uncomp, tx);
2493
2494         delta = pa->originusedsnap -
2495             odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2496         ASSERT3S(delta, <=, 0);
2497         ASSERT3U(pa->used, >=, -delta);
2498         dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2499         dsl_dir_diduse_space(odd, DD_USED_HEAD,
2500             -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2501
2502         origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2503
2504         /* log history record */
2505         spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2506             cr, "dataset = %llu", hds->ds_object);
2507
2508         dsl_dir_close(odd, FTAG);
2509 }
2510
2511 static char *snaplist_tag = "snaplist";
2512 /*
2513  * Make a list of dsl_dataset_t's for the snapshots between first_obj
2514  * (exclusive) and last_obj (inclusive).  The list will be in reverse
2515  * order (last_obj will be the list_head()).  If first_obj == 0, do all
2516  * snapshots back to this dataset's origin.
2517  */
2518 static int
2519 snaplist_make(dsl_pool_t *dp, boolean_t own,
2520     uint64_t first_obj, uint64_t last_obj, list_t *l)
2521 {
2522         uint64_t obj = last_obj;
2523
2524         ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2525
2526         list_create(l, sizeof (struct promotenode),
2527             offsetof(struct promotenode, link));
2528
2529         while (obj != first_obj) {
2530                 dsl_dataset_t *ds;
2531                 struct promotenode *snap;
2532                 int err;
2533
2534                 if (own) {
2535                         err = dsl_dataset_own_obj(dp, obj,
2536                             0, snaplist_tag, &ds);
2537                         if (err == 0)
2538                                 dsl_dataset_make_exclusive(ds, snaplist_tag);
2539                 } else {
2540                         err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2541                 }
2542                 if (err == ENOENT) {
2543                         /* lost race with snapshot destroy */
2544                         struct promotenode *last = list_tail(l);
2545                         ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2546                         obj = last->ds->ds_phys->ds_prev_snap_obj;
2547                         continue;
2548                 } else if (err) {
2549                         return (err);
2550                 }
2551
2552                 if (first_obj == 0)
2553                         first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2554
2555                 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2556                 snap->ds = ds;
2557                 list_insert_tail(l, snap);
2558                 obj = ds->ds_phys->ds_prev_snap_obj;
2559         }
2560
2561         return (0);
2562 }
2563
2564 static int
2565 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2566 {
2567         struct promotenode *snap;
2568
2569         *spacep = 0;
2570         for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2571                 uint64_t used;
2572                 int err = bplist_space_birthrange(&snap->ds->ds_deadlist,
2573                     mintxg, UINT64_MAX, &used);
2574                 if (err)
2575                         return (err);
2576                 *spacep += used;
2577         }
2578         return (0);
2579 }
2580
2581 static void
2582 snaplist_destroy(list_t *l, boolean_t own)
2583 {
2584         struct promotenode *snap;
2585
2586         if (!list_link_active(&l->list_head))
2587                 return;
2588
2589         while ((snap = list_tail(l)) != NULL) {
2590                 list_remove(l, snap);
2591                 if (own)
2592                         dsl_dataset_disown(snap->ds, snaplist_tag);
2593                 else
2594                         dsl_dataset_rele(snap->ds, snaplist_tag);
2595                 kmem_free(snap, sizeof (struct promotenode));
2596         }
2597         list_destroy(l);
2598 }
2599
2600 /*
2601  * Promote a clone.  Nomenclature note:
2602  * "clone" or "cds": the original clone which is being promoted
2603  * "origin" or "ods": the snapshot which is originally clone's origin
2604  * "origin head" or "ohds": the dataset which is the head
2605  * (filesystem/volume) for the origin
2606  * "origin origin": the origin of the origin's filesystem (typically
2607  * NULL, indicating that the clone is not a clone of a clone).
2608  */
2609 int
2610 dsl_dataset_promote(const char *name)
2611 {
2612         dsl_dataset_t *ds;
2613         dsl_dir_t *dd;
2614         dsl_pool_t *dp;
2615         dmu_object_info_t doi;
2616         struct promotearg pa = { 0 };
2617         struct promotenode *snap;
2618         int err;
2619
2620         err = dsl_dataset_hold(name, FTAG, &ds);
2621         if (err)
2622                 return (err);
2623         dd = ds->ds_dir;
2624         dp = dd->dd_pool;
2625
2626         err = dmu_object_info(dp->dp_meta_objset,
2627             ds->ds_phys->ds_snapnames_zapobj, &doi);
2628         if (err) {
2629                 dsl_dataset_rele(ds, FTAG);
2630                 return (err);
2631         }
2632
2633         if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
2634                 dsl_dataset_rele(ds, FTAG);
2635                 return (EINVAL);
2636         }
2637
2638         /*
2639          * We are going to inherit all the snapshots taken before our
2640          * origin (i.e., our new origin will be our parent's origin).
2641          * Take ownership of them so that we can rename them into our
2642          * namespace.
2643          */
2644         rw_enter(&dp->dp_config_rwlock, RW_READER);
2645
2646         err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
2647             &pa.shared_snaps);
2648         if (err != 0)
2649                 goto out;
2650
2651         err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
2652         if (err != 0)
2653                 goto out;
2654
2655         snap = list_head(&pa.shared_snaps);
2656         ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2657         err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
2658             snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
2659         if (err != 0)
2660                 goto out;
2661
2662         if (dsl_dir_is_clone(snap->ds->ds_dir)) {
2663                 err = dsl_dataset_own_obj(dp,
2664                     snap->ds->ds_dir->dd_phys->dd_origin_obj,
2665                     0, FTAG, &pa.origin_origin);
2666                 if (err != 0)
2667                         goto out;
2668         }
2669
2670 out:
2671         rw_exit(&dp->dp_config_rwlock);
2672
2673         /*
2674          * Add in 128x the snapnames zapobj size, since we will be moving
2675          * a bunch of snapnames to the promoted ds, and dirtying their
2676          * bonus buffers.
2677          */
2678         if (err == 0) {
2679                 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
2680                     dsl_dataset_promote_sync, ds, &pa,
2681                     2 + 2 * doi.doi_physical_blks);
2682         }
2683
2684         snaplist_destroy(&pa.shared_snaps, B_TRUE);
2685         snaplist_destroy(&pa.clone_snaps, B_FALSE);
2686         snaplist_destroy(&pa.origin_snaps, B_FALSE);
2687         if (pa.origin_origin)
2688                 dsl_dataset_disown(pa.origin_origin, FTAG);
2689         dsl_dataset_rele(ds, FTAG);
2690         return (err);
2691 }
2692
2693 struct cloneswaparg {
2694         dsl_dataset_t *cds; /* clone dataset */
2695         dsl_dataset_t *ohds; /* origin's head dataset */
2696         boolean_t force;
2697         int64_t unused_refres_delta; /* change in unconsumed refreservation */
2698 };
2699
2700 /* ARGSUSED */
2701 static int
2702 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
2703 {
2704         struct cloneswaparg *csa = arg1;
2705
2706         /* they should both be heads */
2707         if (dsl_dataset_is_snapshot(csa->cds) ||
2708             dsl_dataset_is_snapshot(csa->ohds))
2709                 return (EINVAL);
2710
2711         /* the branch point should be just before them */
2712         if (csa->cds->ds_prev != csa->ohds->ds_prev)
2713                 return (EINVAL);
2714
2715         /* cds should be the clone */
2716         if (csa->cds->ds_prev->ds_phys->ds_next_snap_obj !=
2717             csa->ohds->ds_object)
2718                 return (EINVAL);
2719
2720         /* the clone should be a child of the origin */
2721         if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
2722                 return (EINVAL);
2723
2724         /* ohds shouldn't be modified unless 'force' */
2725         if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
2726                 return (ETXTBSY);
2727
2728         /* adjust amount of any unconsumed refreservation */
2729         csa->unused_refres_delta =
2730             (int64_t)MIN(csa->ohds->ds_reserved,
2731             csa->ohds->ds_phys->ds_unique_bytes) -
2732             (int64_t)MIN(csa->ohds->ds_reserved,
2733             csa->cds->ds_phys->ds_unique_bytes);
2734
2735         if (csa->unused_refres_delta > 0 &&
2736             csa->unused_refres_delta >
2737             dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
2738                 return (ENOSPC);
2739
2740         return (0);
2741 }
2742
2743 /* ARGSUSED */
2744 static void
2745 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
2746 {
2747         struct cloneswaparg *csa = arg1;
2748         dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
2749
2750         ASSERT(csa->cds->ds_reserved == 0);
2751         ASSERT(csa->cds->ds_quota == csa->ohds->ds_quota);
2752
2753         dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
2754         dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
2755         dmu_buf_will_dirty(csa->cds->ds_prev->ds_dbuf, tx);
2756
2757         if (csa->cds->ds_user_ptr != NULL) {
2758                 csa->cds->ds_user_evict_func(csa->cds, csa->cds->ds_user_ptr);
2759                 csa->cds->ds_user_ptr = NULL;
2760         }
2761
2762         if (csa->ohds->ds_user_ptr != NULL) {
2763                 csa->ohds->ds_user_evict_func(csa->ohds,
2764                     csa->ohds->ds_user_ptr);
2765                 csa->ohds->ds_user_ptr = NULL;
2766         }
2767
2768         /* reset origin's unique bytes */
2769         VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist,
2770             csa->cds->ds_prev->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2771             &csa->cds->ds_prev->ds_phys->ds_unique_bytes));
2772
2773         /* swap blkptrs */
2774         {
2775                 blkptr_t tmp;
2776                 tmp = csa->ohds->ds_phys->ds_bp;
2777                 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
2778                 csa->cds->ds_phys->ds_bp = tmp;
2779         }
2780
2781         /* set dd_*_bytes */
2782         {
2783                 int64_t dused, dcomp, duncomp;
2784                 uint64_t cdl_used, cdl_comp, cdl_uncomp;
2785                 uint64_t odl_used, odl_comp, odl_uncomp;
2786
2787                 ASSERT3U(csa->cds->ds_dir->dd_phys->
2788                     dd_used_breakdown[DD_USED_SNAP], ==, 0);
2789
2790                 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used,
2791                     &cdl_comp, &cdl_uncomp));
2792                 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used,
2793                     &odl_comp, &odl_uncomp));
2794
2795                 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
2796                     (csa->ohds->ds_phys->ds_used_bytes + odl_used);
2797                 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
2798                     (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
2799                 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
2800                     cdl_uncomp -
2801                     (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
2802
2803                 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
2804                     dused, dcomp, duncomp, tx);
2805                 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
2806                     -dused, -dcomp, -duncomp, tx);
2807
2808                 /*
2809                  * The difference in the space used by snapshots is the
2810                  * difference in snapshot space due to the head's
2811                  * deadlist (since that's the only thing that's
2812                  * changing that affects the snapused).
2813                  */
2814                 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist,
2815                     csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used));
2816                 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist,
2817                     csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used));
2818                 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
2819                     DD_USED_HEAD, DD_USED_SNAP, tx);
2820         }
2821
2822 #define SWITCH64(x, y) \
2823         { \
2824                 uint64_t __tmp = (x); \
2825                 (x) = (y); \
2826                 (y) = __tmp; \
2827         }
2828
2829         /* swap ds_*_bytes */
2830         SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
2831             csa->cds->ds_phys->ds_used_bytes);
2832         SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
2833             csa->cds->ds_phys->ds_compressed_bytes);
2834         SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
2835             csa->cds->ds_phys->ds_uncompressed_bytes);
2836         SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
2837             csa->cds->ds_phys->ds_unique_bytes);
2838
2839         /* apply any parent delta for change in unconsumed refreservation */
2840         dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
2841             csa->unused_refres_delta, 0, 0, tx);
2842
2843         /* swap deadlists */
2844         bplist_close(&csa->cds->ds_deadlist);
2845         bplist_close(&csa->ohds->ds_deadlist);
2846         SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
2847             csa->cds->ds_phys->ds_deadlist_obj);
2848         VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
2849             csa->cds->ds_phys->ds_deadlist_obj));
2850         VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
2851             csa->ohds->ds_phys->ds_deadlist_obj));
2852
2853         dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx);
2854 }
2855
2856 /*
2857  * Swap 'clone' with its origin head file system.  Used at the end
2858  * of "online recv" to swizzle the file system to the new version.
2859  */
2860 int
2861 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
2862     boolean_t force)
2863 {
2864         struct cloneswaparg csa;
2865         int error;
2866
2867         ASSERT(clone->ds_owner);
2868         ASSERT(origin_head->ds_owner);
2869 retry:
2870         /* Need exclusive access for the swap */
2871         rw_enter(&clone->ds_rwlock, RW_WRITER);
2872         if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
2873                 rw_exit(&clone->ds_rwlock);
2874                 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
2875                 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
2876                         rw_exit(&origin_head->ds_rwlock);
2877                         goto retry;
2878                 }
2879         }
2880         csa.cds = clone;
2881         csa.ohds = origin_head;
2882         csa.force = force;
2883         error = dsl_sync_task_do(clone->ds_dir->dd_pool,
2884             dsl_dataset_clone_swap_check,
2885             dsl_dataset_clone_swap_sync, &csa, NULL, 9);
2886         return (error);
2887 }
2888
2889 /*
2890  * Given a pool name and a dataset object number in that pool,
2891  * return the name of that dataset.
2892  */
2893 int
2894 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
2895 {
2896         spa_t *spa;
2897         dsl_pool_t *dp;
2898         dsl_dataset_t *ds;
2899         int error;
2900
2901         if ((error = spa_open(pname, &spa, FTAG)) != 0)
2902                 return (error);
2903         dp = spa_get_dsl(spa);
2904         rw_enter(&dp->dp_config_rwlock, RW_READER);
2905         if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
2906                 dsl_dataset_name(ds, buf);
2907                 dsl_dataset_rele(ds, FTAG);
2908         }
2909         rw_exit(&dp->dp_config_rwlock);
2910         spa_close(spa, FTAG);
2911
2912         return (error);
2913 }
2914
2915 int
2916 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
2917     uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
2918 {
2919         int error = 0;
2920
2921         ASSERT3S(asize, >, 0);
2922
2923         /*
2924          * *ref_rsrv is the portion of asize that will come from any
2925          * unconsumed refreservation space.
2926          */
2927         *ref_rsrv = 0;
2928
2929         mutex_enter(&ds->ds_lock);
2930         /*
2931          * Make a space adjustment for reserved bytes.
2932          */
2933         if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
2934                 ASSERT3U(*used, >=,
2935                     ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2936                 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2937                 *ref_rsrv =
2938                     asize - MIN(asize, parent_delta(ds, asize + inflight));
2939         }
2940
2941         if (!check_quota || ds->ds_quota == 0) {
2942                 mutex_exit(&ds->ds_lock);
2943                 return (0);
2944         }
2945         /*
2946          * If they are requesting more space, and our current estimate
2947          * is over quota, they get to try again unless the actual
2948          * on-disk is over quota and there are no pending changes (which
2949          * may free up space for us).
2950          */
2951         if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
2952                 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
2953                         error = ERESTART;
2954                 else
2955                         error = EDQUOT;
2956         }
2957         mutex_exit(&ds->ds_lock);
2958
2959         return (error);
2960 }
2961
2962 /* ARGSUSED */
2963 static int
2964 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
2965 {
2966         dsl_dataset_t *ds = arg1;
2967         uint64_t *quotap = arg2;
2968         uint64_t new_quota = *quotap;
2969
2970         if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
2971                 return (ENOTSUP);
2972
2973         if (new_quota == 0)
2974                 return (0);
2975
2976         if (new_quota < ds->ds_phys->ds_used_bytes ||
2977             new_quota < ds->ds_reserved)
2978                 return (ENOSPC);
2979
2980         return (0);
2981 }
2982
2983 /* ARGSUSED */
2984 void
2985 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
2986 {
2987         dsl_dataset_t *ds = arg1;
2988         uint64_t *quotap = arg2;
2989         uint64_t new_quota = *quotap;
2990
2991         dmu_buf_will_dirty(ds->ds_dbuf, tx);
2992
2993         ds->ds_quota = new_quota;
2994
2995         dsl_prop_set_uint64_sync(ds->ds_dir, "refquota", new_quota, cr, tx);
2996
2997         spa_history_internal_log(LOG_DS_REFQUOTA, ds->ds_dir->dd_pool->dp_spa,
2998             tx, cr, "%lld dataset = %llu ",
2999             (longlong_t)new_quota, ds->ds_object);
3000 }
3001
3002 int
3003 dsl_dataset_set_quota(const char *dsname, uint64_t quota)
3004 {
3005         dsl_dataset_t *ds;
3006         int err;
3007
3008         err = dsl_dataset_hold(dsname, FTAG, &ds);
3009         if (err)
3010                 return (err);
3011
3012         if (quota != ds->ds_quota) {
3013                 /*
3014                  * If someone removes a file, then tries to set the quota, we
3015                  * want to make sure the file freeing takes effect.
3016                  */
3017                 txg_wait_open(ds->ds_dir->dd_pool, 0);
3018
3019                 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3020                     dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3021                     ds, &quota, 0);
3022         }
3023         dsl_dataset_rele(ds, FTAG);
3024         return (err);
3025 }
3026
3027 static int
3028 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3029 {
3030         dsl_dataset_t *ds = arg1;
3031         uint64_t *reservationp = arg2;
3032         uint64_t new_reservation = *reservationp;
3033         uint64_t unique;
3034
3035         if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3036             SPA_VERSION_REFRESERVATION)
3037                 return (ENOTSUP);
3038
3039         if (dsl_dataset_is_snapshot(ds))
3040                 return (EINVAL);
3041
3042         /*
3043          * If we are doing the preliminary check in open context, the
3044          * space estimates may be inaccurate.
3045          */
3046         if (!dmu_tx_is_syncing(tx))
3047                 return (0);
3048
3049         mutex_enter(&ds->ds_lock);
3050         unique = dsl_dataset_unique(ds);
3051         mutex_exit(&ds->ds_lock);
3052
3053         if (MAX(unique, new_reservation) > MAX(unique, ds->ds_reserved)) {
3054                 uint64_t delta = MAX(unique, new_reservation) -
3055                     MAX(unique, ds->ds_reserved);
3056
3057                 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3058                         return (ENOSPC);
3059                 if (ds->ds_quota > 0 &&
3060                     new_reservation > ds->ds_quota)
3061                         return (ENOSPC);
3062         }
3063
3064         return (0);
3065 }
3066
3067 /* ARGSUSED */
3068 static void
3069 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr,
3070     dmu_tx_t *tx)
3071 {
3072         dsl_dataset_t *ds = arg1;
3073         uint64_t *reservationp = arg2;
3074         uint64_t new_reservation = *reservationp;
3075         uint64_t unique;
3076         int64_t delta;
3077
3078         dmu_buf_will_dirty(ds->ds_dbuf, tx);
3079
3080         mutex_enter(&ds->ds_dir->dd_lock);
3081         mutex_enter(&ds->ds_lock);
3082         unique = dsl_dataset_unique(ds);
3083         delta = MAX(0, (int64_t)(new_reservation - unique)) -
3084             MAX(0, (int64_t)(ds->ds_reserved - unique));
3085         ds->ds_reserved = new_reservation;
3086         mutex_exit(&ds->ds_lock);
3087
3088         dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3089         mutex_exit(&ds->ds_dir->dd_lock);
3090         dsl_prop_set_uint64_sync(ds->ds_dir, "refreservation",
3091             new_reservation, cr, tx);
3092
3093         spa_history_internal_log(LOG_DS_REFRESERV,
3094             ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu",
3095             (longlong_t)new_reservation, ds->ds_object);
3096 }
3097
3098 int
3099 dsl_dataset_set_reservation(const char *dsname, uint64_t reservation)
3100 {
3101         dsl_dataset_t *ds;
3102         int err;
3103
3104         err = dsl_dataset_hold(dsname, FTAG, &ds);
3105         if (err)
3106                 return (err);
3107
3108         err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3109             dsl_dataset_set_reservation_check,
3110             dsl_dataset_set_reservation_sync, ds, &reservation, 0);
3111         dsl_dataset_rele(ds, FTAG);
3112         return (err);
3113 }