sys/cddl/contrib/opensolaris/uts/common/fs/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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Portions Copyright (c) 2011 Martin Matuska <mm@FreeBSD.org>
  24  * Copyright (c) 2013, 2014 by Delphix. All rights reserved.
  25  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
  26  * Copyright (c) 2014 RackTop Systems.
  27  */
  28
  29 #include <sys/dmu_objset.h>
  30 #include <sys/dsl_dataset.h>
  31 #include <sys/dsl_dir.h>
  32 #include <sys/dsl_prop.h>
  33 #include <sys/dsl_synctask.h>
  34 #include <sys/dmu_traverse.h>
  35 #include <sys/dmu_impl.h>
  36 #include <sys/dmu_tx.h>
  37 #include <sys/arc.h>
  38 #include <sys/zio.h>
  39 #include <sys/zap.h>
  40 #include <sys/zfeature.h>
  41 #include <sys/unique.h>
  42 #include <sys/zfs_context.h>
  43 #include <sys/zfs_ioctl.h>
  44 #include <sys/spa.h>
  45 #include <sys/zfs_znode.h>
  46 #include <sys/zfs_onexit.h>
  47 #include <sys/zvol.h>
  48 #include <sys/dsl_scan.h>
  49 #include <sys/dsl_deadlist.h>
  50 #include <sys/dsl_destroy.h>
  51 #include <sys/dsl_userhold.h>
  52 #include <sys/dsl_bookmark.h>
  53
  54 #define SWITCH64(x, y) \
  55         { \
  56                 uint64_t __tmp = (x); \
  57                 (x) = (y); \
  58                 (y) = __tmp; \
  59         }
  60
  61 #define DS_REF_MAX      (1ULL << 62)
  62
  63 #define DSL_DEADLIST_BLOCKSIZE  SPA_MAXBLOCKSIZE
  64
  65 /*
  66  * Figure out how much of this delta should be propogated to the dsl_dir
  67  * layer.  If there's a refreservation, that space has already been
  68  * partially accounted for in our ancestors.
  69  */
  70 static int64_t
  71 parent_delta(dsl_dataset_t *ds, int64_t delta)
  72 {
  73         uint64_t old_bytes, new_bytes;
  74
  75         if (ds->ds_reserved == 0)
  76                 return (delta);
  77
  78         old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
  79         new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
  80
  81         ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
  82         return (new_bytes - old_bytes);
  83 }
  84
  85 void
  86 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
  87 {
  88         int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
  89         int compressed = BP_GET_PSIZE(bp);
  90         int uncompressed = BP_GET_UCSIZE(bp);
  91         int64_t delta;
  92
  93         dprintf_bp(bp, "ds=%p", ds);
  94
  95         ASSERT(dmu_tx_is_syncing(tx));
  96         /* It could have been compressed away to nothing */
  97         if (BP_IS_HOLE(bp))
  98                 return;
  99         ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
 100         ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
 101         if (ds == NULL) {
 102                 dsl_pool_mos_diduse_space(tx->tx_pool,
 103                     used, compressed, uncompressed);
 104                 return;
 105         }
 106
 107         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 108         mutex_enter(&ds->ds_lock);
 109         delta = parent_delta(ds, used);
 110         ds->ds_phys->ds_referenced_bytes += used;
 111         ds->ds_phys->ds_compressed_bytes += compressed;
 112         ds->ds_phys->ds_uncompressed_bytes += uncompressed;
 113         ds->ds_phys->ds_unique_bytes += used;
 114         mutex_exit(&ds->ds_lock);
 115         dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
 116             compressed, uncompressed, tx);
 117         dsl_dir_transfer_space(ds->ds_dir, used - delta,
 118             DD_USED_REFRSRV, DD_USED_HEAD, tx);
 119 }
 120
 121 int
 122 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
 123     boolean_t async)
 124 {
 125         int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
 126         int compressed = BP_GET_PSIZE(bp);
 127         int uncompressed = BP_GET_UCSIZE(bp);
 128
 129         if (BP_IS_HOLE(bp))
 130                 return (0);
 131
 132         ASSERT(dmu_tx_is_syncing(tx));
 133         ASSERT(bp->blk_birth <= tx->tx_txg);
 134
 135         if (ds == NULL) {
 136                 dsl_free(tx->tx_pool, tx->tx_txg, bp);
 137                 dsl_pool_mos_diduse_space(tx->tx_pool,
 138                     -used, -compressed, -uncompressed);
 139                 return (used);
 140         }
 141         ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
 142
 143         ASSERT(!dsl_dataset_is_snapshot(ds));
 144         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 145
 146         if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
 147                 int64_t delta;
 148
 149                 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
 150                 dsl_free(tx->tx_pool, tx->tx_txg, bp);
 151
 152                 mutex_enter(&ds->ds_lock);
 153                 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
 154                     !DS_UNIQUE_IS_ACCURATE(ds));
 155                 delta = parent_delta(ds, -used);
 156                 ds->ds_phys->ds_unique_bytes -= used;
 157                 mutex_exit(&ds->ds_lock);
 158                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
 159                     delta, -compressed, -uncompressed, tx);
 160                 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
 161                     DD_USED_REFRSRV, DD_USED_HEAD, tx);
 162         } else {
 163                 dprintf_bp(bp, "putting on dead list: %s", "");
 164                 if (async) {
 165                         /*
 166                          * We are here as part of zio's write done callback,
 167                          * which means we're a zio interrupt thread.  We can't
 168                          * call dsl_deadlist_insert() now because it may block
 169                          * waiting for I/O.  Instead, put bp on the deferred
 170                          * queue and let dsl_pool_sync() finish the job.
 171                          */
 172                         bplist_append(&ds->ds_pending_deadlist, bp);
 173                 } else {
 174                         dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
 175                 }
 176                 ASSERT3U(ds->ds_prev->ds_object, ==,
 177                     ds->ds_phys->ds_prev_snap_obj);
 178                 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
 179                 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
 180                 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
 181                     ds->ds_object && bp->blk_birth >
 182                     ds->ds_prev->ds_phys->ds_prev_snap_txg) {
 183                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
 184                         mutex_enter(&ds->ds_prev->ds_lock);
 185                         ds->ds_prev->ds_phys->ds_unique_bytes += used;
 186                         mutex_exit(&ds->ds_prev->ds_lock);
 187                 }
 188                 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
 189                         dsl_dir_transfer_space(ds->ds_dir, used,
 190                             DD_USED_HEAD, DD_USED_SNAP, tx);
 191                 }
 192         }
 193         mutex_enter(&ds->ds_lock);
 194         ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used);
 195         ds->ds_phys->ds_referenced_bytes -= used;
 196         ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
 197         ds->ds_phys->ds_compressed_bytes -= compressed;
 198         ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
 199         ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
 200         mutex_exit(&ds->ds_lock);
 201
 202         return (used);
 203 }
 204
 205 uint64_t
 206 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
 207 {
 208         uint64_t trysnap = 0;
 209
 210         if (ds == NULL)
 211                 return (0);
 212         /*
 213          * The snapshot creation could fail, but that would cause an
 214          * incorrect FALSE return, which would only result in an
 215          * overestimation of the amount of space that an operation would
 216          * consume, which is OK.
 217          *
 218          * There's also a small window where we could miss a pending
 219          * snapshot, because we could set the sync task in the quiescing
 220          * phase.  So this should only be used as a guess.
 221          */
 222         if (ds->ds_trysnap_txg >
 223             spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
 224                 trysnap = ds->ds_trysnap_txg;
 225         return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
 226 }
 227
 228 boolean_t
 229 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
 230     uint64_t blk_birth)
 231 {
 232         if (blk_birth <= dsl_dataset_prev_snap_txg(ds) ||
 233             (bp != NULL && BP_IS_HOLE(bp)))
 234                 return (B_FALSE);
 235
 236         ddt_prefetch(dsl_dataset_get_spa(ds), bp);
 237
 238         return (B_TRUE);
 239 }
 240
 241 /* ARGSUSED */
 242 static void
 243 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
 244 {
 245         dsl_dataset_t *ds = dsv;
 246
 247         ASSERT(ds->ds_owner == NULL);
 248
 249         unique_remove(ds->ds_fsid_guid);
 250
 251         if (ds->ds_objset != NULL)
 252                 dmu_objset_evict(ds->ds_objset);
 253
 254         if (ds->ds_prev) {
 255                 dsl_dataset_rele(ds->ds_prev, ds);
 256                 ds->ds_prev = NULL;
 257         }
 258
 259         bplist_destroy(&ds->ds_pending_deadlist);
 260         if (ds->ds_phys->ds_deadlist_obj != 0)
 261                 dsl_deadlist_close(&ds->ds_deadlist);
 262         if (ds->ds_dir)
 263                 dsl_dir_rele(ds->ds_dir, ds);
 264
 265         ASSERT(!list_link_active(&ds->ds_synced_link));
 266
 267         if (mutex_owned(&ds->ds_lock))
 268                 mutex_exit(&ds->ds_lock);
 269         mutex_destroy(&ds->ds_lock);
 270         if (mutex_owned(&ds->ds_opening_lock))
 271                 mutex_exit(&ds->ds_opening_lock);
 272         mutex_destroy(&ds->ds_opening_lock);
 273         mutex_destroy(&ds->ds_sendstream_lock);
 274         refcount_destroy(&ds->ds_longholds);
 275
 276         kmem_free(ds, sizeof (dsl_dataset_t));
 277 }
 278
 279 int
 280 dsl_dataset_get_snapname(dsl_dataset_t *ds)
 281 {
 282         dsl_dataset_phys_t *headphys;
 283         int err;
 284         dmu_buf_t *headdbuf;
 285         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 286         objset_t *mos = dp->dp_meta_objset;
 287
 288         if (ds->ds_snapname[0])
 289                 return (0);
 290         if (ds->ds_phys->ds_next_snap_obj == 0)
 291                 return (0);
 292
 293         err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
 294             FTAG, &headdbuf);
 295         if (err != 0)
 296                 return (err);
 297         headphys = headdbuf->db_data;
 298         err = zap_value_search(dp->dp_meta_objset,
 299             headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
 300         dmu_buf_rele(headdbuf, FTAG);
 301         return (err);
 302 }
 303
 304 int
 305 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
 306 {
 307         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 308         uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
 309         matchtype_t mt;
 310         int err;
 311
 312         if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
 313                 mt = MT_FIRST;
 314         else
 315                 mt = MT_EXACT;
 316
 317         err = zap_lookup_norm(mos, snapobj, name, 8, 1,
 318             value, mt, NULL, 0, NULL);
 319         if (err == ENOTSUP && mt == MT_FIRST)
 320                 err = zap_lookup(mos, snapobj, name, 8, 1, value);
 321         return (err);
 322 }
 323
 324 int
 325 dsl_dataset_snap_remove(dsl_dataset_t *ds, const char *name, dmu_tx_t *tx,
 326     boolean_t adj_cnt)
 327 {
 328         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 329         uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
 330         matchtype_t mt;
 331         int err;
 332
 333         dsl_dir_snap_cmtime_update(ds->ds_dir);
 334
 335         if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
 336                 mt = MT_FIRST;
 337         else
 338                 mt = MT_EXACT;
 339
 340         err = zap_remove_norm(mos, snapobj, name, mt, tx);
 341         if (err == ENOTSUP && mt == MT_FIRST)
 342                 err = zap_remove(mos, snapobj, name, tx);
 343
 344         if (err == 0 && adj_cnt)
 345                 dsl_fs_ss_count_adjust(ds->ds_dir, -1,
 346                     DD_FIELD_SNAPSHOT_COUNT, tx);
 347
 348         return (err);
 349 }
 350
 351 int
 352 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 353     dsl_dataset_t **dsp)
 354 {
 355         objset_t *mos = dp->dp_meta_objset;
 356         dmu_buf_t *dbuf;
 357         dsl_dataset_t *ds;
 358         int err;
 359         dmu_object_info_t doi;
 360
 361         ASSERT(dsl_pool_config_held(dp));
 362
 363         err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
 364         if (err != 0)
 365                 return (err);
 366
 367         /* Make sure dsobj has the correct object type. */
 368         dmu_object_info_from_db(dbuf, &doi);
 369         if (doi.doi_bonus_type != DMU_OT_DSL_DATASET) {
 370                 dmu_buf_rele(dbuf, tag);
 371                 return (SET_ERROR(EINVAL));
 372         }
 373
 374         ds = dmu_buf_get_user(dbuf);
 375         if (ds == NULL) {
 376                 dsl_dataset_t *winner = NULL;
 377
 378                 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
 379                 ds->ds_dbuf = dbuf;
 380                 ds->ds_object = dsobj;
 381                 ds->ds_phys = dbuf->db_data;
 382
 383                 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
 384                 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
 385                 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
 386                 refcount_create(&ds->ds_longholds);
 387
 388                 bplist_create(&ds->ds_pending_deadlist);
 389                 dsl_deadlist_open(&ds->ds_deadlist,
 390                     mos, ds->ds_phys->ds_deadlist_obj);
 391
 392                 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
 393                     offsetof(dmu_sendarg_t, dsa_link));
 394
 395                 if (err == 0) {
 396                         err = dsl_dir_hold_obj(dp,
 397                             ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
 398                 }
 399                 if (err != 0) {
 400                         mutex_destroy(&ds->ds_lock);
 401                         mutex_destroy(&ds->ds_opening_lock);
 402                         mutex_destroy(&ds->ds_sendstream_lock);
 403                         refcount_destroy(&ds->ds_longholds);
 404                         bplist_destroy(&ds->ds_pending_deadlist);
 405                         dsl_deadlist_close(&ds->ds_deadlist);
 406                         kmem_free(ds, sizeof (dsl_dataset_t));
 407                         dmu_buf_rele(dbuf, tag);
 408                         return (err);
 409                 }
 410
 411                 if (!dsl_dataset_is_snapshot(ds)) {
 412                         ds->ds_snapname[0] = '\0';
 413                         if (ds->ds_phys->ds_prev_snap_obj != 0) {
 414                                 err = dsl_dataset_hold_obj(dp,
 415                                     ds->ds_phys->ds_prev_snap_obj,
 416                                     ds, &ds->ds_prev);
 417                         }
 418                         if (doi.doi_type == DMU_OTN_ZAP_METADATA) {
 419                                 int zaperr = zap_lookup(mos, ds->ds_object,
 420                                     DS_FIELD_BOOKMARK_NAMES,
 421                                     sizeof (ds->ds_bookmarks), 1,
 422                                     &ds->ds_bookmarks);
 423                                 if (zaperr != ENOENT)
 424                                         VERIFY0(zaperr);
 425                         }
 426                 } else {
 427                         if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
 428                                 err = dsl_dataset_get_snapname(ds);
 429                         if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
 430                                 err = zap_count(
 431                                     ds->ds_dir->dd_pool->dp_meta_objset,
 432                                     ds->ds_phys->ds_userrefs_obj,
 433                                     &ds->ds_userrefs);
 434                         }
 435                 }
 436
 437                 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
 438                         err = dsl_prop_get_int_ds(ds,
 439                             zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
 440                             &ds->ds_reserved);
 441                         if (err == 0) {
 442                                 err = dsl_prop_get_int_ds(ds,
 443                                     zfs_prop_to_name(ZFS_PROP_REFQUOTA),
 444                                     &ds->ds_quota);
 445                         }
 446                 } else {
 447                         ds->ds_reserved = ds->ds_quota = 0;
 448                 }
 449
 450                 if (err != 0 || (winner = dmu_buf_set_user_ie(dbuf, ds,
 451                     &ds->ds_phys, dsl_dataset_evict)) != NULL) {
 452                         bplist_destroy(&ds->ds_pending_deadlist);
 453                         dsl_deadlist_close(&ds->ds_deadlist);
 454                         if (ds->ds_prev)
 455                                 dsl_dataset_rele(ds->ds_prev, ds);
 456                         dsl_dir_rele(ds->ds_dir, ds);
 457                         mutex_destroy(&ds->ds_lock);
 458                         mutex_destroy(&ds->ds_opening_lock);
 459                         mutex_destroy(&ds->ds_sendstream_lock);
 460                         refcount_destroy(&ds->ds_longholds);
 461                         kmem_free(ds, sizeof (dsl_dataset_t));
 462                         if (err != 0) {
 463                                 dmu_buf_rele(dbuf, tag);
 464                                 return (err);
 465                         }
 466                         ds = winner;
 467                 } else {
 468                         ds->ds_fsid_guid =
 469                             unique_insert(ds->ds_phys->ds_fsid_guid);
 470                 }
 471         }
 472         ASSERT3P(ds->ds_dbuf, ==, dbuf);
 473         ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
 474         ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
 475             spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
 476             dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
 477         *dsp = ds;
 478         return (0);
 479 }
 480
 481 int
 482 dsl_dataset_hold(dsl_pool_t *dp, const char *name,
 483     void *tag, dsl_dataset_t **dsp)
 484 {
 485         dsl_dir_t *dd;
 486         const char *snapname;
 487         uint64_t obj;
 488         int err = 0;
 489
 490         err = dsl_dir_hold(dp, name, FTAG, &dd, &snapname);
 491         if (err != 0)
 492                 return (err);
 493
 494         ASSERT(dsl_pool_config_held(dp));
 495         obj = dd->dd_phys->dd_head_dataset_obj;
 496         if (obj != 0)
 497                 err = dsl_dataset_hold_obj(dp, obj, tag, dsp);
 498         else
 499                 err = SET_ERROR(ENOENT);
 500
 501         /* we may be looking for a snapshot */
 502         if (err == 0 && snapname != NULL) {
 503                 dsl_dataset_t *ds;
 504
 505                 if (*snapname++ != '@') {
 506                         dsl_dataset_rele(*dsp, tag);
 507                         dsl_dir_rele(dd, FTAG);
 508                         return (SET_ERROR(ENOENT));
 509                 }
 510
 511                 dprintf("looking for snapshot '%s'\n", snapname);
 512                 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
 513                 if (err == 0)
 514                         err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
 515                 dsl_dataset_rele(*dsp, tag);
 516
 517                 if (err == 0) {
 518                         mutex_enter(&ds->ds_lock);
 519                         if (ds->ds_snapname[0] == 0)
 520                                 (void) strlcpy(ds->ds_snapname, snapname,
 521                                     sizeof (ds->ds_snapname));
 522                         mutex_exit(&ds->ds_lock);
 523                         *dsp = ds;
 524                 }
 525         }
 526
 527         dsl_dir_rele(dd, FTAG);
 528         return (err);
 529 }
 530
 531 int
 532 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj,
 533     void *tag, dsl_dataset_t **dsp)
 534 {
 535         int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
 536         if (err != 0)
 537                 return (err);
 538         if (!dsl_dataset_tryown(*dsp, tag)) {
 539                 dsl_dataset_rele(*dsp, tag);
 540                 *dsp = NULL;
 541                 return (SET_ERROR(EBUSY));
 542         }
 543         return (0);
 544 }
 545
 546 int
 547 dsl_dataset_own(dsl_pool_t *dp, const char *name,
 548     void *tag, dsl_dataset_t **dsp)
 549 {
 550         int err = dsl_dataset_hold(dp, name, tag, dsp);
 551         if (err != 0)
 552                 return (err);
 553         if (!dsl_dataset_tryown(*dsp, tag)) {
 554                 dsl_dataset_rele(*dsp, tag);
 555                 return (SET_ERROR(EBUSY));
 556         }
 557         return (0);
 558 }
 559
 560 /*
 561  * See the comment above dsl_pool_hold() for details.  In summary, a long
 562  * hold is used to prevent destruction of a dataset while the pool hold
 563  * is dropped, allowing other concurrent operations (e.g. spa_sync()).
 564  *
 565  * The dataset and pool must be held when this function is called.  After it
 566  * is called, the pool hold may be released while the dataset is still held
 567  * and accessed.
 568  */
 569 void
 570 dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag)
 571 {
 572         ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
 573         (void) refcount_add(&ds->ds_longholds, tag);
 574 }
 575
 576 void
 577 dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag)
 578 {
 579         (void) refcount_remove(&ds->ds_longholds, tag);
 580 }
 581
 582 /* Return B_TRUE if there are any long holds on this dataset. */
 583 boolean_t
 584 dsl_dataset_long_held(dsl_dataset_t *ds)
 585 {
 586         return (!refcount_is_zero(&ds->ds_longholds));
 587 }
 588
 589 void
 590 dsl_dataset_name(dsl_dataset_t *ds, char *name)
 591 {
 592         if (ds == NULL) {
 593                 (void) strcpy(name, "mos");
 594         } else {
 595                 dsl_dir_name(ds->ds_dir, name);
 596                 VERIFY0(dsl_dataset_get_snapname(ds));
 597                 if (ds->ds_snapname[0]) {
 598                         (void) strcat(name, "@");
 599                         /*
 600                          * We use a "recursive" mutex so that we
 601                          * can call dprintf_ds() with ds_lock held.
 602                          */
 603                         if (!MUTEX_HELD(&ds->ds_lock)) {
 604                                 mutex_enter(&ds->ds_lock);
 605                                 (void) strcat(name, ds->ds_snapname);
 606                                 mutex_exit(&ds->ds_lock);
 607                         } else {
 608                                 (void) strcat(name, ds->ds_snapname);
 609                         }
 610                 }
 611         }
 612 }
 613
 614 void
 615 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
 616 {
 617         dmu_buf_rele(ds->ds_dbuf, tag);
 618 }
 619
 620 void
 621 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
 622 {
 623         ASSERT(ds->ds_owner == tag && ds->ds_dbuf != NULL);
 624
 625         mutex_enter(&ds->ds_lock);
 626         ds->ds_owner = NULL;
 627         mutex_exit(&ds->ds_lock);
 628         dsl_dataset_long_rele(ds, tag);
 629         if (ds->ds_dbuf != NULL)
 630                 dsl_dataset_rele(ds, tag);
 631         else
 632                 dsl_dataset_evict(NULL, ds);
 633 }
 634
 635 boolean_t
 636 dsl_dataset_tryown(dsl_dataset_t *ds, void *tag)
 637 {
 638         boolean_t gotit = FALSE;
 639
 640         mutex_enter(&ds->ds_lock);
 641         if (ds->ds_owner == NULL && !DS_IS_INCONSISTENT(ds)) {
 642                 ds->ds_owner = tag;
 643                 dsl_dataset_long_hold(ds, tag);
 644                 gotit = TRUE;
 645         }
 646         mutex_exit(&ds->ds_lock);
 647         return (gotit);
 648 }
 649
 650 uint64_t
 651 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
 652     uint64_t flags, dmu_tx_t *tx)
 653 {
 654         dsl_pool_t *dp = dd->dd_pool;
 655         dmu_buf_t *dbuf;
 656         dsl_dataset_phys_t *dsphys;
 657         uint64_t dsobj;
 658         objset_t *mos = dp->dp_meta_objset;
 659
 660         if (origin == NULL)
 661                 origin = dp->dp_origin_snap;
 662
 663         ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
 664         ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
 665         ASSERT(dmu_tx_is_syncing(tx));
 666         ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
 667
 668         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
 669             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
 670         VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
 671         dmu_buf_will_dirty(dbuf, tx);
 672         dsphys = dbuf->db_data;
 673         bzero(dsphys, sizeof (dsl_dataset_phys_t));
 674         dsphys->ds_dir_obj = dd->dd_object;
 675         dsphys->ds_flags = flags;
 676         dsphys->ds_fsid_guid = unique_create();
 677         do {
 678                 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
 679                     sizeof (dsphys->ds_guid));
 680         } while (dsphys->ds_guid == 0);
 681         dsphys->ds_snapnames_zapobj =
 682             zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
 683             DMU_OT_NONE, 0, tx);
 684         dsphys->ds_creation_time = gethrestime_sec();
 685         dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
 686
 687         if (origin == NULL) {
 688                 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
 689         } else {
 690                 dsl_dataset_t *ohds; /* head of the origin snapshot */
 691
 692                 dsphys->ds_prev_snap_obj = origin->ds_object;
 693                 dsphys->ds_prev_snap_txg =
 694                     origin->ds_phys->ds_creation_txg;
 695                 dsphys->ds_referenced_bytes =
 696                     origin->ds_phys->ds_referenced_bytes;
 697                 dsphys->ds_compressed_bytes =
 698                     origin->ds_phys->ds_compressed_bytes;
 699                 dsphys->ds_uncompressed_bytes =
 700                     origin->ds_phys->ds_uncompressed_bytes;
 701                 dsphys->ds_bp = origin->ds_phys->ds_bp;
 702                 dsphys->ds_flags |= origin->ds_phys->ds_flags;
 703
 704                 dmu_buf_will_dirty(origin->ds_dbuf, tx);
 705                 origin->ds_phys->ds_num_children++;
 706
 707                 VERIFY0(dsl_dataset_hold_obj(dp,
 708                     origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
 709                 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
 710                     dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
 711                 dsl_dataset_rele(ohds, FTAG);
 712
 713                 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
 714                         if (origin->ds_phys->ds_next_clones_obj == 0) {
 715                                 origin->ds_phys->ds_next_clones_obj =
 716                                     zap_create(mos,
 717                                     DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
 718                         }
 719                         VERIFY0(zap_add_int(mos,
 720                             origin->ds_phys->ds_next_clones_obj, dsobj, tx));
 721                 }
 722
 723                 dmu_buf_will_dirty(dd->dd_dbuf, tx);
 724                 dd->dd_phys->dd_origin_obj = origin->ds_object;
 725                 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
 726                         if (origin->ds_dir->dd_phys->dd_clones == 0) {
 727                                 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
 728                                 origin->ds_dir->dd_phys->dd_clones =
 729                                     zap_create(mos,
 730                                     DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
 731                         }
 732                         VERIFY0(zap_add_int(mos,
 733                             origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
 734                 }
 735         }
 736
 737         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
 738                 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
 739
 740         dmu_buf_rele(dbuf, FTAG);
 741
 742         dmu_buf_will_dirty(dd->dd_dbuf, tx);
 743         dd->dd_phys->dd_head_dataset_obj = dsobj;
 744
 745         return (dsobj);
 746 }
 747
 748 static void
 749 dsl_dataset_zero_zil(dsl_dataset_t *ds, dmu_tx_t *tx)
 750 {
 751         objset_t *os;
 752
 753         VERIFY0(dmu_objset_from_ds(ds, &os));
 754         bzero(&os->os_zil_header, sizeof (os->os_zil_header));
 755         dsl_dataset_dirty(ds, tx);
 756 }
 757
 758 uint64_t
 759 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
 760     dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
 761 {
 762         dsl_pool_t *dp = pdd->dd_pool;
 763         uint64_t dsobj, ddobj;
 764         dsl_dir_t *dd;
 765
 766         ASSERT(dmu_tx_is_syncing(tx));
 767         ASSERT(lastname[0] != '@');
 768
 769         ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
 770         VERIFY0(dsl_dir_hold_obj(dp, ddobj, lastname, FTAG, &dd));
 771
 772         dsobj = dsl_dataset_create_sync_dd(dd, origin,
 773             flags & ~DS_CREATE_FLAG_NODIRTY, tx);
 774
 775         dsl_deleg_set_create_perms(dd, tx, cr);
 776
 777         /*
 778          * Since we're creating a new node we know it's a leaf, so we can
 779          * initialize the counts if the limit feature is active.
 780          */
 781         if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_FS_SS_LIMIT)) {
 782                 uint64_t cnt = 0;
 783                 objset_t *os = dd->dd_pool->dp_meta_objset;
 784
 785                 dsl_dir_zapify(dd, tx);
 786                 VERIFY0(zap_add(os, dd->dd_object, DD_FIELD_FILESYSTEM_COUNT,
 787                     sizeof (cnt), 1, &cnt, tx));
 788                 VERIFY0(zap_add(os, dd->dd_object, DD_FIELD_SNAPSHOT_COUNT,
 789                     sizeof (cnt), 1, &cnt, tx));
 790         }
 791
 792         dsl_dir_rele(dd, FTAG);
 793
 794         /*
 795          * If we are creating a clone, make sure we zero out any stale
 796          * data from the origin snapshots zil header.
 797          */
 798         if (origin != NULL && !(flags & DS_CREATE_FLAG_NODIRTY)) {
 799                 dsl_dataset_t *ds;
 800
 801                 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
 802                 dsl_dataset_zero_zil(ds, tx);
 803                 dsl_dataset_rele(ds, FTAG);
 804         }
 805
 806         return (dsobj);
 807 }
 808
 809 #ifdef __FreeBSD__
 810 /* FreeBSD ioctl compat begin */
 811 struct destroyarg {
 812         nvlist_t *nvl;
 813         const char *snapname;
 814 };
 815
 816 static int
 817 dsl_check_snap_cb(const char *name, void *arg)
 818 {
 819         struct destroyarg *da = arg;
 820         dsl_dataset_t *ds;
 821         char *dsname;
 822
 823         dsname = kmem_asprintf("%s@%s", name, da->snapname);
 824         fnvlist_add_boolean(da->nvl, dsname);
 825         kmem_free(dsname, strlen(dsname) + 1);
 826
 827         return (0);
 828 }
 829
 830 int
 831 dmu_get_recursive_snaps_nvl(char *fsname, const char *snapname,
 832     nvlist_t *snaps)
 833 {
 834         struct destroyarg *da;
 835         int err;
 836
 837         da = kmem_zalloc(sizeof (struct destroyarg), KM_SLEEP);
 838         da->nvl = snaps;
 839         da->snapname = snapname;
 840         err = dmu_objset_find(fsname, dsl_check_snap_cb, da,
 841             DS_FIND_CHILDREN);
 842         kmem_free(da, sizeof (struct destroyarg));
 843
 844         return (err);
 845 }
 846 /* FreeBSD ioctl compat end */
 847 #endif /* __FreeBSD__ */
 848
 849 /*
 850  * The unique space in the head dataset can be calculated by subtracting
 851  * the space used in the most recent snapshot, that is still being used
 852  * in this file system, from the space currently in use.  To figure out
 853  * the space in the most recent snapshot still in use, we need to take
 854  * the total space used in the snapshot and subtract out the space that
 855  * has been freed up since the snapshot was taken.
 856  */
 857 void
 858 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
 859 {
 860         uint64_t mrs_used;
 861         uint64_t dlused, dlcomp, dluncomp;
 862
 863         ASSERT(!dsl_dataset_is_snapshot(ds));
 864
 865         if (ds->ds_phys->ds_prev_snap_obj != 0)
 866                 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
 867         else
 868                 mrs_used = 0;
 869
 870         dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
 871
 872         ASSERT3U(dlused, <=, mrs_used);
 873         ds->ds_phys->ds_unique_bytes =
 874             ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
 875
 876         if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
 877             SPA_VERSION_UNIQUE_ACCURATE)
 878                 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
 879 }
 880
 881 void
 882 dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
 883     dmu_tx_t *tx)
 884 {
 885         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 886         uint64_t count;
 887         int err;
 888
 889         ASSERT(ds->ds_phys->ds_num_children >= 2);
 890         err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
 891         /*
 892          * The err should not be ENOENT, but a bug in a previous version
 893          * of the code could cause upgrade_clones_cb() to not set
 894          * ds_next_snap_obj when it should, leading to a missing entry.
 895          * If we knew that the pool was created after
 896          * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
 897          * ENOENT.  However, at least we can check that we don't have
 898          * too many entries in the next_clones_obj even after failing to
 899          * remove this one.
 900          */
 901         if (err != ENOENT)
 902                 VERIFY0(err);
 903         ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
 904             &count));
 905         ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
 906 }
 907
 908
 909 blkptr_t *
 910 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
 911 {
 912         return (&ds->ds_phys->ds_bp);
 913 }
 914
 915 void
 916 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
 917 {
 918         ASSERT(dmu_tx_is_syncing(tx));
 919         /* If it's the meta-objset, set dp_meta_rootbp */
 920         if (ds == NULL) {
 921                 tx->tx_pool->dp_meta_rootbp = *bp;
 922         } else {
 923                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
 924                 ds->ds_phys->ds_bp = *bp;
 925         }
 926 }
 927
 928 spa_t *
 929 dsl_dataset_get_spa(dsl_dataset_t *ds)
 930 {
 931         return (ds->ds_dir->dd_pool->dp_spa);
 932 }
 933
 934 void
 935 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
 936 {
 937         dsl_pool_t *dp;
 938
 939         if (ds == NULL) /* this is the meta-objset */
 940                 return;
 941
 942         ASSERT(ds->ds_objset != NULL);
 943
 944         if (ds->ds_phys->ds_next_snap_obj != 0)
 945                 panic("dirtying snapshot!");
 946
 947         dp = ds->ds_dir->dd_pool;
 948
 949         if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
 950                 /* up the hold count until we can be written out */
 951                 dmu_buf_add_ref(ds->ds_dbuf, ds);
 952         }
 953 }
 954
 955 boolean_t
 956 dsl_dataset_is_dirty(dsl_dataset_t *ds)
 957 {
 958         for (int t = 0; t < TXG_SIZE; t++) {
 959                 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
 960                     ds, t))
 961                         return (B_TRUE);
 962         }
 963         return (B_FALSE);
 964 }
 965
 966 static int
 967 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
 968 {
 969         uint64_t asize;
 970
 971         if (!dmu_tx_is_syncing(tx))
 972                 return (0);
 973
 974         /*
 975          * If there's an fs-only reservation, any blocks that might become
 976          * owned by the snapshot dataset must be accommodated by space
 977          * outside of the reservation.
 978          */
 979         ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
 980         asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
 981         if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
 982                 return (SET_ERROR(ENOSPC));
 983
 984         /*
 985          * Propagate any reserved space for this snapshot to other
 986          * snapshot checks in this sync group.
 987          */
 988         if (asize > 0)
 989                 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
 990
 991         return (0);
 992 }
 993
 994 typedef struct dsl_dataset_snapshot_arg {
 995         nvlist_t *ddsa_snaps;
 996         nvlist_t *ddsa_props;
 997         nvlist_t *ddsa_errors;
 998         cred_t *ddsa_cr;
 999 } dsl_dataset_snapshot_arg_t;
1000
1001 int
1002 dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
1003     dmu_tx_t *tx, boolean_t recv, uint64_t cnt, cred_t *cr)
1004 {
1005         int error;
1006         uint64_t value;
1007
1008         ds->ds_trysnap_txg = tx->tx_txg;
1009
1010         if (!dmu_tx_is_syncing(tx))
1011                 return (0);
1012
1013         /*
1014          * We don't allow multiple snapshots of the same txg.  If there
1015          * is already one, try again.
1016          */
1017         if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1018                 return (SET_ERROR(EAGAIN));
1019
1020         /*
1021          * Check for conflicting snapshot name.
1022          */
1023         error = dsl_dataset_snap_lookup(ds, snapname, &value);
1024         if (error == 0)
1025                 return (SET_ERROR(EEXIST));
1026         if (error != ENOENT)
1027                 return (error);
1028
1029         /*
1030          * We don't allow taking snapshots of inconsistent datasets, such as
1031          * those into which we are currently receiving.  However, if we are
1032          * creating this snapshot as part of a receive, this check will be
1033          * executed atomically with respect to the completion of the receive
1034          * itself but prior to the clearing of DS_FLAG_INCONSISTENT; in this
1035          * case we ignore this, knowing it will be fixed up for us shortly in
1036          * dmu_recv_end_sync().
1037          */
1038         if (!recv && DS_IS_INCONSISTENT(ds))
1039                 return (SET_ERROR(EBUSY));
1040
1041         /*
1042          * Skip the check for temporary snapshots or if we have already checked
1043          * the counts in dsl_dataset_snapshot_check. This means we really only
1044          * check the count here when we're receiving a stream.
1045          */
1046         if (cnt != 0 && cr != NULL) {
1047                 error = dsl_fs_ss_limit_check(ds->ds_dir, cnt,
1048                     ZFS_PROP_SNAPSHOT_LIMIT, NULL, cr);
1049                 if (error != 0)
1050                         return (error);
1051         }
1052
1053         error = dsl_dataset_snapshot_reserve_space(ds, tx);
1054         if (error != 0)
1055                 return (error);
1056
1057         return (0);
1058 }
1059
1060 static int
1061 dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx)
1062 {
1063         dsl_dataset_snapshot_arg_t *ddsa = arg;
1064         dsl_pool_t *dp = dmu_tx_pool(tx);
1065         nvpair_t *pair;
1066         int rv = 0;
1067
1068         /*
1069          * Pre-compute how many total new snapshots will be created for each
1070          * level in the tree and below. This is needed for validating the
1071          * snapshot limit when either taking a recursive snapshot or when
1072          * taking multiple snapshots.
1073          *
1074          * The problem is that the counts are not actually adjusted when
1075          * we are checking, only when we finally sync. For a single snapshot,
1076          * this is easy, the count will increase by 1 at each node up the tree,
1077          * but its more complicated for the recursive/multiple snapshot case.
1078          *
1079          * The dsl_fs_ss_limit_check function does recursively check the count
1080          * at each level up the tree but since it is validating each snapshot
1081          * independently we need to be sure that we are validating the complete
1082          * count for the entire set of snapshots. We do this by rolling up the
1083          * counts for each component of the name into an nvlist and then
1084          * checking each of those cases with the aggregated count.
1085          *
1086          * This approach properly handles not only the recursive snapshot
1087          * case (where we get all of those on the ddsa_snaps list) but also
1088          * the sibling case (e.g. snapshot a/b and a/c so that we will also
1089          * validate the limit on 'a' using a count of 2).
1090          *
1091          * We validate the snapshot names in the third loop and only report
1092          * name errors once.
1093          */
1094         if (dmu_tx_is_syncing(tx)) {
1095                 nvlist_t *cnt_track = NULL;
1096                 cnt_track = fnvlist_alloc();
1097
1098                 /* Rollup aggregated counts into the cnt_track list */
1099                 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1100                     pair != NULL;
1101                     pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1102                         char *pdelim;
1103                         uint64_t val;
1104                         char nm[MAXPATHLEN];
1105
1106                         (void) strlcpy(nm, nvpair_name(pair), sizeof (nm));
1107                         pdelim = strchr(nm, '@');
1108                         if (pdelim == NULL)
1109                                 continue;
1110                         *pdelim = '\0';
1111
1112                         do {
1113                                 if (nvlist_lookup_uint64(cnt_track, nm,
1114                                     &val) == 0) {
1115                                         /* update existing entry */
1116                                         fnvlist_add_uint64(cnt_track, nm,
1117                                             val + 1);
1118                                 } else {
1119                                         /* add to list */
1120                                         fnvlist_add_uint64(cnt_track, nm, 1);
1121                                 }
1122
1123                                 pdelim = strrchr(nm, '/');
1124                                 if (pdelim != NULL)
1125                                         *pdelim = '\0';
1126                         } while (pdelim != NULL);
1127                 }
1128
1129                 /* Check aggregated counts at each level */
1130                 for (pair = nvlist_next_nvpair(cnt_track, NULL);
1131                     pair != NULL; pair = nvlist_next_nvpair(cnt_track, pair)) {
1132                         int error = 0;
1133                         char *name;
1134                         uint64_t cnt = 0;
1135                         dsl_dataset_t *ds;
1136
1137                         name = nvpair_name(pair);
1138                         cnt = fnvpair_value_uint64(pair);
1139                         ASSERT(cnt > 0);
1140
1141                         error = dsl_dataset_hold(dp, name, FTAG, &ds);
1142                         if (error == 0) {
1143                                 error = dsl_fs_ss_limit_check(ds->ds_dir, cnt,
1144                                     ZFS_PROP_SNAPSHOT_LIMIT, NULL,
1145                                     ddsa->ddsa_cr);
1146                                 dsl_dataset_rele(ds, FTAG);
1147                         }
1148
1149                         if (error != 0) {
1150                                 if (ddsa->ddsa_errors != NULL)
1151                                         fnvlist_add_int32(ddsa->ddsa_errors,
1152                                             name, error);
1153                                 rv = error;
1154                                 /* only report one error for this check */
1155                                 break;
1156                         }
1157                 }
1158                 nvlist_free(cnt_track);
1159         }
1160
1161         for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1162             pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1163                 int error = 0;
1164                 dsl_dataset_t *ds;
1165                 char *name, *atp;
1166                 char dsname[MAXNAMELEN];
1167
1168                 name = nvpair_name(pair);
1169                 if (strlen(name) >= MAXNAMELEN)
1170                         error = SET_ERROR(ENAMETOOLONG);
1171                 if (error == 0) {
1172                         atp = strchr(name, '@');
1173                         if (atp == NULL)
1174                                 error = SET_ERROR(EINVAL);
1175                         if (error == 0)
1176                                 (void) strlcpy(dsname, name, atp - name + 1);
1177                 }
1178                 if (error == 0)
1179                         error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
1180                 if (error == 0) {
1181                         /* passing 0/NULL skips dsl_fs_ss_limit_check */
1182                         error = dsl_dataset_snapshot_check_impl(ds,
1183                             atp + 1, tx, B_FALSE, 0, NULL);
1184                         dsl_dataset_rele(ds, FTAG);
1185                 }
1186
1187                 if (error != 0) {
1188                         if (ddsa->ddsa_errors != NULL) {
1189                                 fnvlist_add_int32(ddsa->ddsa_errors,
1190                                     name, error);
1191                         }
1192                         rv = error;
1193                 }
1194         }
1195
1196         return (rv);
1197 }
1198
1199 void
1200 dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
1201     dmu_tx_t *tx)
1202 {
1203         static zil_header_t zero_zil;
1204
1205         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1206         dmu_buf_t *dbuf;
1207         dsl_dataset_phys_t *dsphys;
1208         uint64_t dsobj, crtxg;
1209         objset_t *mos = dp->dp_meta_objset;
1210         objset_t *os;
1211
1212         ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
1213
1214         /*
1215          * If we are on an old pool, the zil must not be active, in which
1216          * case it will be zeroed.  Usually zil_suspend() accomplishes this.
1217          */
1218         ASSERT(spa_version(dmu_tx_pool(tx)->dp_spa) >= SPA_VERSION_FAST_SNAP ||
1219             dmu_objset_from_ds(ds, &os) != 0 ||
1220             bcmp(&os->os_phys->os_zil_header, &zero_zil,
1221             sizeof (zero_zil)) == 0);
1222
1223         dsl_fs_ss_count_adjust(ds->ds_dir, 1, DD_FIELD_SNAPSHOT_COUNT, tx);
1224
1225         /*
1226          * The origin's ds_creation_txg has to be < TXG_INITIAL
1227          */
1228         if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1229                 crtxg = 1;
1230         else
1231                 crtxg = tx->tx_txg;
1232
1233         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1234             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1235         VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1236         dmu_buf_will_dirty(dbuf, tx);
1237         dsphys = dbuf->db_data;
1238         bzero(dsphys, sizeof (dsl_dataset_phys_t));
1239         dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1240         dsphys->ds_fsid_guid = unique_create();
1241         do {
1242                 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1243                     sizeof (dsphys->ds_guid));
1244         } while (dsphys->ds_guid == 0);
1245         dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
1246         dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
1247         dsphys->ds_next_snap_obj = ds->ds_object;
1248         dsphys->ds_num_children = 1;
1249         dsphys->ds_creation_time = gethrestime_sec();
1250         dsphys->ds_creation_txg = crtxg;
1251         dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
1252         dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
1253         dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
1254         dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
1255         dsphys->ds_flags = ds->ds_phys->ds_flags;
1256         dsphys->ds_bp = ds->ds_phys->ds_bp;
1257         dmu_buf_rele(dbuf, FTAG);
1258
1259         ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
1260         if (ds->ds_prev) {
1261                 uint64_t next_clones_obj =
1262                     ds->ds_prev->ds_phys->ds_next_clones_obj;
1263                 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
1264                     ds->ds_object ||
1265                     ds->ds_prev->ds_phys->ds_num_children > 1);
1266                 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1267                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1268                         ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1269                             ds->ds_prev->ds_phys->ds_creation_txg);
1270                         ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
1271                 } else if (next_clones_obj != 0) {
1272                         dsl_dataset_remove_from_next_clones(ds->ds_prev,
1273                             dsphys->ds_next_snap_obj, tx);
1274                         VERIFY0(zap_add_int(mos,
1275                             next_clones_obj, dsobj, tx));
1276                 }
1277         }
1278
1279         /*
1280          * If we have a reference-reservation on this dataset, we will
1281          * need to increase the amount of refreservation being charged
1282          * since our unique space is going to zero.
1283          */
1284         if (ds->ds_reserved) {
1285                 int64_t delta;
1286                 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
1287                 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1288                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1289                     delta, 0, 0, tx);
1290         }
1291
1292         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1293         ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
1294             UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
1295         dsl_deadlist_close(&ds->ds_deadlist);
1296         dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1297         dsl_deadlist_add_key(&ds->ds_deadlist,
1298             ds->ds_phys->ds_prev_snap_txg, tx);
1299
1300         ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
1301         ds->ds_phys->ds_prev_snap_obj = dsobj;
1302         ds->ds_phys->ds_prev_snap_txg = crtxg;
1303         ds->ds_phys->ds_unique_bytes = 0;
1304         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1305                 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1306
1307         VERIFY0(zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
1308             snapname, 8, 1, &dsobj, tx));
1309
1310         if (ds->ds_prev)
1311                 dsl_dataset_rele(ds->ds_prev, ds);
1312         VERIFY0(dsl_dataset_hold_obj(dp,
1313             ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
1314
1315         dsl_scan_ds_snapshotted(ds, tx);
1316
1317         dsl_dir_snap_cmtime_update(ds->ds_dir);
1318
1319         spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
1320 }
1321
1322 static void
1323 dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx)
1324 {
1325         dsl_dataset_snapshot_arg_t *ddsa = arg;
1326         dsl_pool_t *dp = dmu_tx_pool(tx);
1327         nvpair_t *pair;
1328
1329         for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1330             pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1331                 dsl_dataset_t *ds;
1332                 char *name, *atp;
1333                 char dsname[MAXNAMELEN];
1334
1335                 name = nvpair_name(pair);
1336                 atp = strchr(name, '@');
1337                 (void) strlcpy(dsname, name, atp - name + 1);
1338                 VERIFY0(dsl_dataset_hold(dp, dsname, FTAG, &ds));
1339
1340                 dsl_dataset_snapshot_sync_impl(ds, atp + 1, tx);
1341                 if (ddsa->ddsa_props != NULL) {
1342                         dsl_props_set_sync_impl(ds->ds_prev,
1343                             ZPROP_SRC_LOCAL, ddsa->ddsa_props, tx);
1344                 }
1345                 dsl_dataset_rele(ds, FTAG);
1346         }
1347 }
1348
1349 /*
1350  * The snapshots must all be in the same pool.
1351  * All-or-nothing: if there are any failures, nothing will be modified.
1352  */
1353 int
1354 dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors)
1355 {
1356         dsl_dataset_snapshot_arg_t ddsa;
1357         nvpair_t *pair;
1358         boolean_t needsuspend;
1359         int error;
1360         spa_t *spa;
1361         char *firstname;
1362         nvlist_t *suspended = NULL;
1363
1364         pair = nvlist_next_nvpair(snaps, NULL);
1365         if (pair == NULL)
1366                 return (0);
1367         firstname = nvpair_name(pair);
1368
1369         error = spa_open(firstname, &spa, FTAG);
1370         if (error != 0)
1371                 return (error);
1372         needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1373         spa_close(spa, FTAG);
1374
1375         if (needsuspend) {
1376                 suspended = fnvlist_alloc();
1377                 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1378                     pair = nvlist_next_nvpair(snaps, pair)) {
1379                         char fsname[MAXNAMELEN];
1380                         char *snapname = nvpair_name(pair);
1381                         char *atp;
1382                         void *cookie;
1383
1384                         atp = strchr(snapname, '@');
1385                         if (atp == NULL) {
1386                                 error = SET_ERROR(EINVAL);
1387                                 break;
1388                         }
1389                         (void) strlcpy(fsname, snapname, atp - snapname + 1);
1390
1391                         error = zil_suspend(fsname, &cookie);
1392                         if (error != 0)
1393                                 break;
1394                         fnvlist_add_uint64(suspended, fsname,
1395                             (uintptr_t)cookie);
1396                 }
1397         }
1398
1399         ddsa.ddsa_snaps = snaps;
1400         ddsa.ddsa_props = props;
1401         ddsa.ddsa_errors = errors;
1402         ddsa.ddsa_cr = CRED();
1403
1404         if (error == 0) {
1405                 error = dsl_sync_task(firstname, dsl_dataset_snapshot_check,
1406                     dsl_dataset_snapshot_sync, &ddsa,
1407                     fnvlist_num_pairs(snaps) * 3, ZFS_SPACE_CHECK_NORMAL);
1408         }
1409
1410         if (suspended != NULL) {
1411                 for (pair = nvlist_next_nvpair(suspended, NULL); pair != NULL;
1412                     pair = nvlist_next_nvpair(suspended, pair)) {
1413                         zil_resume((void *)(uintptr_t)
1414                             fnvpair_value_uint64(pair));
1415                 }
1416                 fnvlist_free(suspended);
1417         }
1418
1419 #ifdef __FreeBSD__
1420 #ifdef _KERNEL
1421         if (error == 0) {
1422                 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1423                     pair = nvlist_next_nvpair(snaps, pair)) {
1424                         char *snapname = nvpair_name(pair);
1425                         zvol_create_minors(snapname);
1426                 }
1427         }
1428 #endif
1429 #endif
1430         return (error);
1431 }
1432
1433 typedef struct dsl_dataset_snapshot_tmp_arg {
1434         const char *ddsta_fsname;
1435         const char *ddsta_snapname;
1436         minor_t ddsta_cleanup_minor;
1437         const char *ddsta_htag;
1438 } dsl_dataset_snapshot_tmp_arg_t;
1439
1440 static int
1441 dsl_dataset_snapshot_tmp_check(void *arg, dmu_tx_t *tx)
1442 {
1443         dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1444         dsl_pool_t *dp = dmu_tx_pool(tx);
1445         dsl_dataset_t *ds;
1446         int error;
1447
1448         error = dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds);
1449         if (error != 0)
1450                 return (error);
1451
1452         /* NULL cred means no limit check for tmp snapshot */
1453         error = dsl_dataset_snapshot_check_impl(ds, ddsta->ddsta_snapname,
1454             tx, B_FALSE, 0, NULL);
1455         if (error != 0) {
1456                 dsl_dataset_rele(ds, FTAG);
1457                 return (error);
1458         }
1459
1460         if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS) {
1461                 dsl_dataset_rele(ds, FTAG);
1462                 return (SET_ERROR(ENOTSUP));
1463         }
1464         error = dsl_dataset_user_hold_check_one(NULL, ddsta->ddsta_htag,
1465             B_TRUE, tx);
1466         if (error != 0) {
1467                 dsl_dataset_rele(ds, FTAG);
1468                 return (error);
1469         }
1470
1471         dsl_dataset_rele(ds, FTAG);
1472         return (0);
1473 }
1474
1475 static void
1476 dsl_dataset_snapshot_tmp_sync(void *arg, dmu_tx_t *tx)
1477 {
1478         dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1479         dsl_pool_t *dp = dmu_tx_pool(tx);
1480         dsl_dataset_t *ds;
1481
1482         VERIFY0(dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds));
1483
1484         dsl_dataset_snapshot_sync_impl(ds, ddsta->ddsta_snapname, tx);
1485         dsl_dataset_user_hold_sync_one(ds->ds_prev, ddsta->ddsta_htag,
1486             ddsta->ddsta_cleanup_minor, gethrestime_sec(), tx);
1487         dsl_destroy_snapshot_sync_impl(ds->ds_prev, B_TRUE, tx);
1488
1489         dsl_dataset_rele(ds, FTAG);
1490 }
1491
1492 int
1493 dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
1494     minor_t cleanup_minor, const char *htag)
1495 {
1496         dsl_dataset_snapshot_tmp_arg_t ddsta;
1497         int error;
1498         spa_t *spa;
1499         boolean_t needsuspend;
1500         void *cookie;
1501
1502         ddsta.ddsta_fsname = fsname;
1503         ddsta.ddsta_snapname = snapname;
1504         ddsta.ddsta_cleanup_minor = cleanup_minor;
1505         ddsta.ddsta_htag = htag;
1506
1507         error = spa_open(fsname, &spa, FTAG);
1508         if (error != 0)
1509                 return (error);
1510         needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1511         spa_close(spa, FTAG);
1512
1513         if (needsuspend) {
1514                 error = zil_suspend(fsname, &cookie);
1515                 if (error != 0)
1516                         return (error);
1517         }
1518
1519         error = dsl_sync_task(fsname, dsl_dataset_snapshot_tmp_check,
1520             dsl_dataset_snapshot_tmp_sync, &ddsta, 3, ZFS_SPACE_CHECK_RESERVED);
1521
1522         if (needsuspend)
1523                 zil_resume(cookie);
1524         return (error);
1525 }
1526
1527
1528 void
1529 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1530 {
1531         ASSERT(dmu_tx_is_syncing(tx));
1532         ASSERT(ds->ds_objset != NULL);
1533         ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
1534
1535         /*
1536          * in case we had to change ds_fsid_guid when we opened it,
1537          * sync it out now.
1538          */
1539         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1540         ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
1541
1542         dmu_objset_sync(ds->ds_objset, zio, tx);
1543 }
1544
1545 static void
1546 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
1547 {
1548         uint64_t count = 0;
1549         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1550         zap_cursor_t zc;
1551         zap_attribute_t za;
1552         nvlist_t *propval = fnvlist_alloc();
1553         nvlist_t *val = fnvlist_alloc();
1554
1555         ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1556
1557         /*
1558          * There may be missing entries in ds_next_clones_obj
1559          * due to a bug in a previous version of the code.
1560          * Only trust it if it has the right number of entries.
1561          */
1562         if (ds->ds_phys->ds_next_clones_obj != 0) {
1563                 VERIFY0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1564                     &count));
1565         }
1566         if (count != ds->ds_phys->ds_num_children - 1)
1567                 goto fail;
1568         for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
1569             zap_cursor_retrieve(&zc, &za) == 0;
1570             zap_cursor_advance(&zc)) {
1571                 dsl_dataset_t *clone;
1572                 char buf[ZFS_MAXNAMELEN];
1573                 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1574                     za.za_first_integer, FTAG, &clone));
1575                 dsl_dir_name(clone->ds_dir, buf);
1576                 fnvlist_add_boolean(val, buf);
1577                 dsl_dataset_rele(clone, FTAG);
1578         }
1579         zap_cursor_fini(&zc);
1580         fnvlist_add_nvlist(propval, ZPROP_VALUE, val);
1581         fnvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval);
1582 fail:
1583         nvlist_free(val);
1584         nvlist_free(propval);
1585 }
1586
1587 void
1588 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1589 {
1590         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1591         uint64_t refd, avail, uobjs, aobjs, ratio;
1592
1593         ASSERT(dsl_pool_config_held(dp));
1594
1595         ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
1596             (ds->ds_phys->ds_uncompressed_bytes * 100 /
1597             ds->ds_phys->ds_compressed_bytes);
1598
1599         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
1600         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
1601             ds->ds_phys->ds_uncompressed_bytes);
1602
1603         if (dsl_dataset_is_snapshot(ds)) {
1604                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
1605                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1606                     ds->ds_phys->ds_unique_bytes);
1607                 get_clones_stat(ds, nv);
1608         } else {
1609                 if (ds->ds_prev != NULL && ds->ds_prev != dp->dp_origin_snap) {
1610                         char buf[MAXNAMELEN];
1611                         dsl_dataset_name(ds->ds_prev, buf);
1612                         dsl_prop_nvlist_add_string(nv, ZFS_PROP_PREV_SNAP, buf);
1613                 }
1614
1615                 dsl_dir_stats(ds->ds_dir, nv);
1616         }
1617
1618         dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1619         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1620         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1621
1622         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1623             ds->ds_phys->ds_creation_time);
1624         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1625             ds->ds_phys->ds_creation_txg);
1626         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1627             ds->ds_quota);
1628         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1629             ds->ds_reserved);
1630         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1631             ds->ds_phys->ds_guid);
1632         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
1633             ds->ds_phys->ds_unique_bytes);
1634         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
1635             ds->ds_object);
1636         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
1637             ds->ds_userrefs);
1638         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
1639             DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
1640
1641         if (ds->ds_phys->ds_prev_snap_obj != 0) {
1642                 uint64_t written, comp, uncomp;
1643                 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1644                 dsl_dataset_t *prev;
1645
1646                 int err = dsl_dataset_hold_obj(dp,
1647                     ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
1648                 if (err == 0) {
1649                         err = dsl_dataset_space_written(prev, ds, &written,
1650                             &comp, &uncomp);
1651                         dsl_dataset_rele(prev, FTAG);
1652                         if (err == 0) {
1653                                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
1654                                     written);
1655                         }
1656                 }
1657         }
1658 }
1659
1660 void
1661 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
1662 {
1663         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1664         ASSERT(dsl_pool_config_held(dp));
1665
1666         stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
1667         stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
1668         stat->dds_guid = ds->ds_phys->ds_guid;
1669         stat->dds_origin[0] = '\0';
1670         if (dsl_dataset_is_snapshot(ds)) {
1671                 stat->dds_is_snapshot = B_TRUE;
1672                 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
1673         } else {
1674                 stat->dds_is_snapshot = B_FALSE;
1675                 stat->dds_num_clones = 0;
1676
1677                 if (dsl_dir_is_clone(ds->ds_dir)) {
1678                         dsl_dataset_t *ods;
1679
1680                         VERIFY0(dsl_dataset_hold_obj(dp,
1681                             ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
1682                         dsl_dataset_name(ods, stat->dds_origin);
1683                         dsl_dataset_rele(ods, FTAG);
1684                 }
1685         }
1686 }
1687
1688 uint64_t
1689 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
1690 {
1691         return (ds->ds_fsid_guid);
1692 }
1693
1694 void
1695 dsl_dataset_space(dsl_dataset_t *ds,
1696     uint64_t *refdbytesp, uint64_t *availbytesp,
1697     uint64_t *usedobjsp, uint64_t *availobjsp)
1698 {
1699         *refdbytesp = ds->ds_phys->ds_referenced_bytes;
1700         *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
1701         if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
1702                 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
1703         if (ds->ds_quota != 0) {
1704                 /*
1705                  * Adjust available bytes according to refquota
1706                  */
1707                 if (*refdbytesp < ds->ds_quota)
1708                         *availbytesp = MIN(*availbytesp,
1709                             ds->ds_quota - *refdbytesp);
1710                 else
1711                         *availbytesp = 0;
1712         }
1713         *usedobjsp = BP_GET_FILL(&ds->ds_phys->ds_bp);
1714         *availobjsp = DN_MAX_OBJECT - *usedobjsp;
1715 }
1716
1717 boolean_t
1718 dsl_dataset_modified_since_snap(dsl_dataset_t *ds, dsl_dataset_t *snap)
1719 {
1720         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1721
1722         ASSERT(dsl_pool_config_held(dp));
1723         if (snap == NULL)
1724                 return (B_FALSE);
1725         if (ds->ds_phys->ds_bp.blk_birth >
1726             snap->ds_phys->ds_creation_txg) {
1727                 objset_t *os, *os_snap;
1728                 /*
1729                  * It may be that only the ZIL differs, because it was
1730                  * reset in the head.  Don't count that as being
1731                  * modified.
1732                  */
1733                 if (dmu_objset_from_ds(ds, &os) != 0)
1734                         return (B_TRUE);
1735                 if (dmu_objset_from_ds(snap, &os_snap) != 0)
1736                         return (B_TRUE);
1737                 return (bcmp(&os->os_phys->os_meta_dnode,
1738                     &os_snap->os_phys->os_meta_dnode,
1739                     sizeof (os->os_phys->os_meta_dnode)) != 0);
1740         }
1741         return (B_FALSE);
1742 }
1743
1744 typedef struct dsl_dataset_rename_snapshot_arg {
1745         const char *ddrsa_fsname;
1746         const char *ddrsa_oldsnapname;
1747         const char *ddrsa_newsnapname;
1748         boolean_t ddrsa_recursive;
1749         dmu_tx_t *ddrsa_tx;
1750 } dsl_dataset_rename_snapshot_arg_t;
1751
1752 /* ARGSUSED */
1753 static int
1754 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
1755     dsl_dataset_t *hds, void *arg)
1756 {
1757         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1758         int error;
1759         uint64_t val;
1760
1761         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1762         if (error != 0) {
1763                 /* ignore nonexistent snapshots */
1764                 return (error == ENOENT ? 0 : error);
1765         }
1766
1767         /* new name should not exist */
1768         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_newsnapname, &val);
1769         if (error == 0)
1770                 error = SET_ERROR(EEXIST);
1771         else if (error == ENOENT)
1772                 error = 0;
1773
1774         /* dataset name + 1 for the "@" + the new snapshot name must fit */
1775         if (dsl_dir_namelen(hds->ds_dir) + 1 +
1776             strlen(ddrsa->ddrsa_newsnapname) >= MAXNAMELEN)
1777                 error = SET_ERROR(ENAMETOOLONG);
1778
1779         return (error);
1780 }
1781
1782 static int
1783 dsl_dataset_rename_snapshot_check(void *arg, dmu_tx_t *tx)
1784 {
1785         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1786         dsl_pool_t *dp = dmu_tx_pool(tx);
1787         dsl_dataset_t *hds;
1788         int error;
1789
1790         error = dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds);
1791         if (error != 0)
1792                 return (error);
1793
1794         if (ddrsa->ddrsa_recursive) {
1795                 error = dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1796                     dsl_dataset_rename_snapshot_check_impl, ddrsa,
1797                     DS_FIND_CHILDREN);
1798         } else {
1799                 error = dsl_dataset_rename_snapshot_check_impl(dp, hds, ddrsa);
1800         }
1801         dsl_dataset_rele(hds, FTAG);
1802         return (error);
1803 }
1804
1805 static int
1806 dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
1807     dsl_dataset_t *hds, void *arg)
1808 {
1809 #ifdef __FreeBSD__
1810 #ifdef _KERNEL
1811         char *oldname, *newname;
1812 #endif
1813 #endif
1814         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1815         dsl_dataset_t *ds;
1816         uint64_t val;
1817         dmu_tx_t *tx = ddrsa->ddrsa_tx;
1818         int error;
1819
1820         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1821         ASSERT(error == 0 || error == ENOENT);
1822         if (error == ENOENT) {
1823                 /* ignore nonexistent snapshots */
1824                 return (0);
1825         }
1826
1827         VERIFY0(dsl_dataset_hold_obj(dp, val, FTAG, &ds));
1828
1829         /* log before we change the name */
1830         spa_history_log_internal_ds(ds, "rename", tx,
1831             "-> @%s", ddrsa->ddrsa_newsnapname);
1832
1833         VERIFY0(dsl_dataset_snap_remove(hds, ddrsa->ddrsa_oldsnapname, tx,
1834             B_FALSE));
1835         mutex_enter(&ds->ds_lock);
1836         (void) strcpy(ds->ds_snapname, ddrsa->ddrsa_newsnapname);
1837         mutex_exit(&ds->ds_lock);
1838         VERIFY0(zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj,
1839             ds->ds_snapname, 8, 1, &ds->ds_object, tx));
1840
1841 #ifdef __FreeBSD__
1842 #ifdef _KERNEL
1843         oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
1844         newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
1845         snprintf(oldname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
1846             ddrsa->ddrsa_oldsnapname);
1847         snprintf(newname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
1848             ddrsa->ddrsa_newsnapname);
1849         zfsvfs_update_fromname(oldname, newname);
1850         zvol_rename_minors(oldname, newname);
1851         kmem_free(newname, MAXPATHLEN);
1852         kmem_free(oldname, MAXPATHLEN);
1853 #endif
1854 #endif
1855         dsl_dataset_rele(ds, FTAG);
1856
1857         return (0);
1858 }
1859
1860 static void
1861 dsl_dataset_rename_snapshot_sync(void *arg, dmu_tx_t *tx)
1862 {
1863         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1864         dsl_pool_t *dp = dmu_tx_pool(tx);
1865         dsl_dataset_t *hds;
1866
1867         VERIFY0(dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds));
1868         ddrsa->ddrsa_tx = tx;
1869         if (ddrsa->ddrsa_recursive) {
1870                 VERIFY0(dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1871                     dsl_dataset_rename_snapshot_sync_impl, ddrsa,
1872                     DS_FIND_CHILDREN));
1873         } else {
1874                 VERIFY0(dsl_dataset_rename_snapshot_sync_impl(dp, hds, ddrsa));
1875         }
1876         dsl_dataset_rele(hds, FTAG);
1877 }
1878
1879 int
1880 dsl_dataset_rename_snapshot(const char *fsname,
1881     const char *oldsnapname, const char *newsnapname, boolean_t recursive)
1882 {
1883         dsl_dataset_rename_snapshot_arg_t ddrsa;
1884
1885         ddrsa.ddrsa_fsname = fsname;
1886         ddrsa.ddrsa_oldsnapname = oldsnapname;
1887         ddrsa.ddrsa_newsnapname = newsnapname;
1888         ddrsa.ddrsa_recursive = recursive;
1889
1890         return (dsl_sync_task(fsname, dsl_dataset_rename_snapshot_check,
1891             dsl_dataset_rename_snapshot_sync, &ddrsa,
1892             1, ZFS_SPACE_CHECK_RESERVED));
1893 }
1894
1895 /*
1896  * If we're doing an ownership handoff, we need to make sure that there is
1897  * only one long hold on the dataset.  We're not allowed to change anything here
1898  * so we don't permanently release the long hold or regular hold here.  We want
1899  * to do this only when syncing to avoid the dataset unexpectedly going away
1900  * when we release the long hold.
1901  */
1902 static int
1903 dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx)
1904 {
1905         boolean_t held;
1906
1907         if (!dmu_tx_is_syncing(tx))
1908                 return (0);
1909
1910         if (owner != NULL) {
1911                 VERIFY3P(ds->ds_owner, ==, owner);
1912                 dsl_dataset_long_rele(ds, owner);
1913         }
1914
1915         held = dsl_dataset_long_held(ds);
1916
1917         if (owner != NULL)
1918                 dsl_dataset_long_hold(ds, owner);
1919
1920         if (held)
1921                 return (SET_ERROR(EBUSY));
1922
1923         return (0);
1924 }
1925
1926 typedef struct dsl_dataset_rollback_arg {
1927         const char *ddra_fsname;
1928         void *ddra_owner;
1929         nvlist_t *ddra_result;
1930 } dsl_dataset_rollback_arg_t;
1931
1932 static int
1933 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
1934 {
1935         dsl_dataset_rollback_arg_t *ddra = arg;
1936         dsl_pool_t *dp = dmu_tx_pool(tx);
1937         dsl_dataset_t *ds;
1938         int64_t unused_refres_delta;
1939         int error;
1940
1941         error = dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds);
1942         if (error != 0)
1943                 return (error);
1944
1945         /* must not be a snapshot */
1946         if (dsl_dataset_is_snapshot(ds)) {
1947                 dsl_dataset_rele(ds, FTAG);
1948                 return (SET_ERROR(EINVAL));
1949         }
1950
1951         /* must have a most recent snapshot */
1952         if (ds->ds_phys->ds_prev_snap_txg < TXG_INITIAL) {
1953                 dsl_dataset_rele(ds, FTAG);
1954                 return (SET_ERROR(EINVAL));
1955         }
1956
1957         /* must not have any bookmarks after the most recent snapshot */
1958         nvlist_t *proprequest = fnvlist_alloc();
1959         fnvlist_add_boolean(proprequest, zfs_prop_to_name(ZFS_PROP_CREATETXG));
1960         nvlist_t *bookmarks = fnvlist_alloc();
1961         error = dsl_get_bookmarks_impl(ds, proprequest, bookmarks);
1962         fnvlist_free(proprequest);
1963         if (error != 0)
1964                 return (error);
1965         for (nvpair_t *pair = nvlist_next_nvpair(bookmarks, NULL);
1966             pair != NULL; pair = nvlist_next_nvpair(bookmarks, pair)) {
1967                 nvlist_t *valuenv =
1968                     fnvlist_lookup_nvlist(fnvpair_value_nvlist(pair),
1969                     zfs_prop_to_name(ZFS_PROP_CREATETXG));
1970                 uint64_t createtxg = fnvlist_lookup_uint64(valuenv, "value");
1971                 if (createtxg > ds->ds_phys->ds_prev_snap_txg) {
1972                         fnvlist_free(bookmarks);
1973                         dsl_dataset_rele(ds, FTAG);
1974                         return (SET_ERROR(EEXIST));
1975                 }
1976         }
1977         fnvlist_free(bookmarks);
1978
1979         error = dsl_dataset_handoff_check(ds, ddra->ddra_owner, tx);
1980         if (error != 0) {
1981                 dsl_dataset_rele(ds, FTAG);
1982                 return (error);
1983         }
1984
1985         /*
1986          * Check if the snap we are rolling back to uses more than
1987          * the refquota.
1988          */
1989         if (ds->ds_quota != 0 &&
1990             ds->ds_prev->ds_phys->ds_referenced_bytes > ds->ds_quota) {
1991                 dsl_dataset_rele(ds, FTAG);
1992                 return (SET_ERROR(EDQUOT));
1993         }
1994
1995         /*
1996          * When we do the clone swap, we will temporarily use more space
1997          * due to the refreservation (the head will no longer have any
1998          * unique space, so the entire amount of the refreservation will need
1999          * to be free).  We will immediately destroy the clone, freeing
2000          * this space, but the freeing happens over many txg's.
2001          */
2002         unused_refres_delta = (int64_t)MIN(ds->ds_reserved,
2003             ds->ds_phys->ds_unique_bytes);
2004
2005         if (unused_refres_delta > 0 &&
2006             unused_refres_delta >
2007             dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) {
2008                 dsl_dataset_rele(ds, FTAG);
2009                 return (SET_ERROR(ENOSPC));
2010         }
2011
2012         dsl_dataset_rele(ds, FTAG);
2013         return (0);
2014 }
2015
2016 static void
2017 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
2018 {
2019         dsl_dataset_rollback_arg_t *ddra = arg;
2020         dsl_pool_t *dp = dmu_tx_pool(tx);
2021         dsl_dataset_t *ds, *clone;
2022         uint64_t cloneobj;
2023         char namebuf[ZFS_MAXNAMELEN];
2024
2025         VERIFY0(dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds));
2026
2027         dsl_dataset_name(ds->ds_prev, namebuf);
2028         fnvlist_add_string(ddra->ddra_result, "target", namebuf);
2029
2030         cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback",
2031             ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx);
2032
2033         VERIFY0(dsl_dataset_hold_obj(dp, cloneobj, FTAG, &clone));
2034
2035         dsl_dataset_clone_swap_sync_impl(clone, ds, tx);
2036         dsl_dataset_zero_zil(ds, tx);
2037
2038         dsl_destroy_head_sync_impl(clone, tx);
2039
2040         dsl_dataset_rele(clone, FTAG);
2041         dsl_dataset_rele(ds, FTAG);
2042 }
2043
2044 /*
2045  * Rolls back the given filesystem or volume to the most recent snapshot.
2046  * The name of the most recent snapshot will be returned under key "target"
2047  * in the result nvlist.
2048  *
2049  * If owner != NULL:
2050  * - The existing dataset MUST be owned by the specified owner at entry
2051  * - Upon return, dataset will still be held by the same owner, whether we
2052  *   succeed or not.
2053  *
2054  * This mode is required any time the existing filesystem is mounted.  See
2055  * notes above zfs_suspend_fs() for further details.
2056  */
2057 int
2058 dsl_dataset_rollback(const char *fsname, void *owner, nvlist_t *result)
2059 {
2060         dsl_dataset_rollback_arg_t ddra;
2061
2062         ddra.ddra_fsname = fsname;
2063         ddra.ddra_owner = owner;
2064         ddra.ddra_result = result;
2065
2066         return (dsl_sync_task(fsname, dsl_dataset_rollback_check,
2067             dsl_dataset_rollback_sync, &ddra,
2068             1, ZFS_SPACE_CHECK_RESERVED));
2069 }
2070
2071 struct promotenode {
2072         list_node_t link;
2073         dsl_dataset_t *ds;
2074 };
2075
2076 typedef struct dsl_dataset_promote_arg {
2077         const char *ddpa_clonename;
2078         dsl_dataset_t *ddpa_clone;
2079         list_t shared_snaps, origin_snaps, clone_snaps;
2080         dsl_dataset_t *origin_origin; /* origin of the origin */
2081         uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2082         char *err_ds;
2083         cred_t *cr;
2084 } dsl_dataset_promote_arg_t;
2085
2086 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2087 static int promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp,
2088     void *tag);
2089 static void promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag);
2090
2091 static int
2092 dsl_dataset_promote_check(void *arg, dmu_tx_t *tx)
2093 {
2094         dsl_dataset_promote_arg_t *ddpa = arg;
2095         dsl_pool_t *dp = dmu_tx_pool(tx);
2096         dsl_dataset_t *hds;
2097         struct promotenode *snap;
2098         dsl_dataset_t *origin_ds;
2099         int err;
2100         uint64_t unused;
2101         uint64_t ss_mv_cnt;
2102
2103         err = promote_hold(ddpa, dp, FTAG);
2104         if (err != 0)
2105                 return (err);
2106
2107         hds = ddpa->ddpa_clone;
2108
2109         if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) {
2110                 promote_rele(ddpa, FTAG);
2111                 return (SET_ERROR(EXDEV));
2112         }
2113
2114         /*
2115          * Compute and check the amount of space to transfer.  Since this is
2116          * so expensive, don't do the preliminary check.
2117          */
2118         if (!dmu_tx_is_syncing(tx)) {
2119                 promote_rele(ddpa, FTAG);
2120                 return (0);
2121         }
2122
2123         snap = list_head(&ddpa->shared_snaps);
2124         origin_ds = snap->ds;
2125
2126         /* compute origin's new unique space */
2127         snap = list_tail(&ddpa->clone_snaps);
2128         ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2129         dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2130             origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2131             &ddpa->unique, &unused, &unused);
2132
2133         /*
2134          * Walk the snapshots that we are moving
2135          *
2136          * Compute space to transfer.  Consider the incremental changes
2137          * to used by each snapshot:
2138          * (my used) = (prev's used) + (blocks born) - (blocks killed)
2139          * So each snapshot gave birth to:
2140          * (blocks born) = (my used) - (prev's used) + (blocks killed)
2141          * So a sequence would look like:
2142          * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2143          * Which simplifies to:
2144          * uN + kN + kN-1 + ... + k1 + k0
2145          * Note however, if we stop before we reach the ORIGIN we get:
2146          * uN + kN + kN-1 + ... + kM - uM-1
2147          */
2148         ss_mv_cnt = 0;
2149         ddpa->used = origin_ds->ds_phys->ds_referenced_bytes;
2150         ddpa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2151         ddpa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2152         for (snap = list_head(&ddpa->shared_snaps); snap;
2153             snap = list_next(&ddpa->shared_snaps, snap)) {
2154                 uint64_t val, dlused, dlcomp, dluncomp;
2155                 dsl_dataset_t *ds = snap->ds;
2156
2157                 ss_mv_cnt++;
2158
2159                 /*
2160                  * If there are long holds, we won't be able to evict
2161                  * the objset.
2162                  */
2163                 if (dsl_dataset_long_held(ds)) {
2164                         err = SET_ERROR(EBUSY);
2165                         goto out;
2166                 }
2167
2168                 /* Check that the snapshot name does not conflict */
2169                 VERIFY0(dsl_dataset_get_snapname(ds));
2170                 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2171                 if (err == 0) {
2172                         (void) strcpy(ddpa->err_ds, snap->ds->ds_snapname);
2173                         err = SET_ERROR(EEXIST);
2174                         goto out;
2175                 }
2176                 if (err != ENOENT)
2177                         goto out;
2178
2179                 /* The very first snapshot does not have a deadlist */
2180                 if (ds->ds_phys->ds_prev_snap_obj == 0)
2181                         continue;
2182
2183                 dsl_deadlist_space(&ds->ds_deadlist,
2184                     &dlused, &dlcomp, &dluncomp);
2185                 ddpa->used += dlused;
2186                 ddpa->comp += dlcomp;
2187                 ddpa->uncomp += dluncomp;
2188         }
2189
2190         /*
2191          * If we are a clone of a clone then we never reached ORIGIN,
2192          * so we need to subtract out the clone origin's used space.
2193          */
2194         if (ddpa->origin_origin) {
2195                 ddpa->used -= ddpa->origin_origin->ds_phys->ds_referenced_bytes;
2196                 ddpa->comp -= ddpa->origin_origin->ds_phys->ds_compressed_bytes;
2197                 ddpa->uncomp -=
2198                     ddpa->origin_origin->ds_phys->ds_uncompressed_bytes;
2199         }
2200
2201         /* Check that there is enough space and limit headroom here */
2202         err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2203             0, ss_mv_cnt, ddpa->used, ddpa->cr);
2204         if (err != 0)
2205                 goto out;
2206
2207         /*
2208          * Compute the amounts of space that will be used by snapshots
2209          * after the promotion (for both origin and clone).  For each,
2210          * it is the amount of space that will be on all of their
2211          * deadlists (that was not born before their new origin).
2212          */
2213         if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2214                 uint64_t space;
2215
2216                 /*
2217                  * Note, typically this will not be a clone of a clone,
2218                  * so dd_origin_txg will be < TXG_INITIAL, so
2219                  * these snaplist_space() -> dsl_deadlist_space_range()
2220                  * calls will be fast because they do not have to
2221                  * iterate over all bps.
2222                  */
2223                 snap = list_head(&ddpa->origin_snaps);
2224                 err = snaplist_space(&ddpa->shared_snaps,
2225                     snap->ds->ds_dir->dd_origin_txg, &ddpa->cloneusedsnap);
2226                 if (err != 0)
2227                         goto out;
2228
2229                 err = snaplist_space(&ddpa->clone_snaps,
2230                     snap->ds->ds_dir->dd_origin_txg, &space);
2231                 if (err != 0)
2232                         goto out;
2233                 ddpa->cloneusedsnap += space;
2234         }
2235         if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2236                 err = snaplist_space(&ddpa->origin_snaps,
2237                     origin_ds->ds_phys->ds_creation_txg, &ddpa->originusedsnap);
2238                 if (err != 0)
2239                         goto out;
2240         }
2241
2242 out:
2243         promote_rele(ddpa, FTAG);
2244         return (err);
2245 }
2246
2247 static void
2248 dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
2249 {
2250         dsl_dataset_promote_arg_t *ddpa = arg;
2251         dsl_pool_t *dp = dmu_tx_pool(tx);
2252         dsl_dataset_t *hds;
2253         struct promotenode *snap;
2254         dsl_dataset_t *origin_ds;
2255         dsl_dataset_t *origin_head;
2256         dsl_dir_t *dd;
2257         dsl_dir_t *odd = NULL;
2258         uint64_t oldnext_obj;
2259         int64_t delta;
2260 #if defined(__FreeBSD__) && defined(_KERNEL)
2261         char *oldname, *newname;
2262 #endif
2263
2264         VERIFY0(promote_hold(ddpa, dp, FTAG));
2265         hds = ddpa->ddpa_clone;
2266
2267         ASSERT0(hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE);
2268
2269         snap = list_head(&ddpa->shared_snaps);
2270         origin_ds = snap->ds;
2271         dd = hds->ds_dir;
2272
2273         snap = list_head(&ddpa->origin_snaps);
2274         origin_head = snap->ds;
2275
2276         /*
2277          * We need to explicitly open odd, since origin_ds's dd will be
2278          * changing.
2279          */
2280         VERIFY0(dsl_dir_hold_obj(dp, origin_ds->ds_dir->dd_object,
2281             NULL, FTAG, &odd));
2282
2283         /* change origin's next snap */
2284         dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2285         oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2286         snap = list_tail(&ddpa->clone_snaps);
2287         ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2288         origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2289
2290         /* change the origin's next clone */
2291         if (origin_ds->ds_phys->ds_next_clones_obj) {
2292                 dsl_dataset_remove_from_next_clones(origin_ds,
2293                     snap->ds->ds_object, tx);
2294                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2295                     origin_ds->ds_phys->ds_next_clones_obj,
2296                     oldnext_obj, tx));
2297         }
2298
2299         /* change origin */
2300         dmu_buf_will_dirty(dd->dd_dbuf, tx);
2301         ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2302         dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2303         dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2304         dmu_buf_will_dirty(odd->dd_dbuf, tx);
2305         odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2306         origin_head->ds_dir->dd_origin_txg =
2307             origin_ds->ds_phys->ds_creation_txg;
2308
2309         /* change dd_clone entries */
2310         if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2311                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2312                     odd->dd_phys->dd_clones, hds->ds_object, tx));
2313                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2314                     ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2315                     hds->ds_object, tx));
2316
2317                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2318                     ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2319                     origin_head->ds_object, tx));
2320                 if (dd->dd_phys->dd_clones == 0) {
2321                         dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2322                             DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2323                 }
2324                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2325                     dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2326         }
2327
2328 #if defined(__FreeBSD__) && defined(_KERNEL)
2329         /* Take the spa_namespace_lock early so zvol renames don't deadlock. */
2330         mutex_enter(&spa_namespace_lock);
2331
2332         oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2333         newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2334 #endif
2335
2336         /* move snapshots to this dir */
2337         for (snap = list_head(&ddpa->shared_snaps); snap;
2338             snap = list_next(&ddpa->shared_snaps, snap)) {
2339                 dsl_dataset_t *ds = snap->ds;
2340
2341                 /*
2342                  * Property callbacks are registered to a particular
2343                  * dsl_dir.  Since ours is changing, evict the objset
2344                  * so that they will be unregistered from the old dsl_dir.
2345                  */
2346                 if (ds->ds_objset) {
2347                         dmu_objset_evict(ds->ds_objset);
2348                         ds->ds_objset = NULL;
2349                 }
2350
2351                 /* move snap name entry */
2352                 VERIFY0(dsl_dataset_get_snapname(ds));
2353                 VERIFY0(dsl_dataset_snap_remove(origin_head,
2354                     ds->ds_snapname, tx, B_TRUE));
2355                 VERIFY0(zap_add(dp->dp_meta_objset,
2356                     hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2357                     8, 1, &ds->ds_object, tx));
2358                 dsl_fs_ss_count_adjust(hds->ds_dir, 1,
2359                     DD_FIELD_SNAPSHOT_COUNT, tx);
2360
2361                 /* change containing dsl_dir */
2362                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2363                 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2364                 ds->ds_phys->ds_dir_obj = dd->dd_object;
2365                 ASSERT3P(ds->ds_dir, ==, odd);
2366                 dsl_dir_rele(ds->ds_dir, ds);
2367                 VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
2368                     NULL, ds, &ds->ds_dir));
2369
2370 #if defined(__FreeBSD__) && defined(_KERNEL)
2371                 dsl_dataset_name(ds, newname);
2372                 zfsvfs_update_fromname(oldname, newname);
2373                 zvol_rename_minors(oldname, newname);
2374 #endif
2375
2376                 /* move any clone references */
2377                 if (ds->ds_phys->ds_next_clones_obj &&
2378                     spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2379                         zap_cursor_t zc;
2380                         zap_attribute_t za;
2381
2382                         for (zap_cursor_init(&zc, dp->dp_meta_objset,
2383                             ds->ds_phys->ds_next_clones_obj);
2384                             zap_cursor_retrieve(&zc, &za) == 0;
2385                             zap_cursor_advance(&zc)) {
2386                                 dsl_dataset_t *cnds;
2387                                 uint64_t o;
2388
2389                                 if (za.za_first_integer == oldnext_obj) {
2390                                         /*
2391                                          * We've already moved the
2392                                          * origin's reference.
2393                                          */
2394                                         continue;
2395                                 }
2396
2397                                 VERIFY0(dsl_dataset_hold_obj(dp,
2398                                     za.za_first_integer, FTAG, &cnds));
2399                                 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2400
2401                                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2402                                     odd->dd_phys->dd_clones, o, tx));
2403                                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2404                                     dd->dd_phys->dd_clones, o, tx));
2405                                 dsl_dataset_rele(cnds, FTAG);
2406                         }
2407                         zap_cursor_fini(&zc);
2408                 }
2409
2410                 ASSERT(!dsl_prop_hascb(ds));
2411         }
2412
2413 #if defined(__FreeBSD__) && defined(_KERNEL)
2414         mutex_exit(&spa_namespace_lock);
2415
2416         kmem_free(newname, MAXPATHLEN);
2417         kmem_free(oldname, MAXPATHLEN);
2418 #endif
2419         /*
2420          * Change space accounting.
2421          * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2422          * both be valid, or both be 0 (resulting in delta == 0).  This
2423          * is true for each of {clone,origin} independently.
2424          */
2425
2426         delta = ddpa->cloneusedsnap -
2427             dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2428         ASSERT3S(delta, >=, 0);
2429         ASSERT3U(ddpa->used, >=, delta);
2430         dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2431         dsl_dir_diduse_space(dd, DD_USED_HEAD,
2432             ddpa->used - delta, ddpa->comp, ddpa->uncomp, tx);
2433
2434         delta = ddpa->originusedsnap -
2435             odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2436         ASSERT3S(delta, <=, 0);
2437         ASSERT3U(ddpa->used, >=, -delta);
2438         dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2439         dsl_dir_diduse_space(odd, DD_USED_HEAD,
2440             -ddpa->used - delta, -ddpa->comp, -ddpa->uncomp, tx);
2441
2442         origin_ds->ds_phys->ds_unique_bytes = ddpa->unique;
2443
2444         /* log history record */
2445         spa_history_log_internal_ds(hds, "promote", tx, "");
2446
2447         dsl_dir_rele(odd, FTAG);
2448         promote_rele(ddpa, FTAG);
2449 }
2450
2451 /*
2452  * Make a list of dsl_dataset_t's for the snapshots between first_obj
2453  * (exclusive) and last_obj (inclusive).  The list will be in reverse
2454  * order (last_obj will be the list_head()).  If first_obj == 0, do all
2455  * snapshots back to this dataset's origin.
2456  */
2457 static int
2458 snaplist_make(dsl_pool_t *dp,
2459     uint64_t first_obj, uint64_t last_obj, list_t *l, void *tag)
2460 {
2461         uint64_t obj = last_obj;
2462
2463         list_create(l, sizeof (struct promotenode),
2464             offsetof(struct promotenode, link));
2465
2466         while (obj != first_obj) {
2467                 dsl_dataset_t *ds;
2468                 struct promotenode *snap;
2469                 int err;
2470
2471                 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
2472                 ASSERT(err != ENOENT);
2473                 if (err != 0)
2474                         return (err);
2475
2476                 if (first_obj == 0)
2477                         first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2478
2479                 snap = kmem_alloc(sizeof (*snap), KM_SLEEP);
2480                 snap->ds = ds;
2481                 list_insert_tail(l, snap);
2482                 obj = ds->ds_phys->ds_prev_snap_obj;
2483         }
2484
2485         return (0);
2486 }
2487
2488 static int
2489 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2490 {
2491         struct promotenode *snap;
2492
2493         *spacep = 0;
2494         for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2495                 uint64_t used, comp, uncomp;
2496                 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2497                     mintxg, UINT64_MAX, &used, &comp, &uncomp);
2498                 *spacep += used;
2499         }
2500         return (0);
2501 }
2502
2503 static void
2504 snaplist_destroy(list_t *l, void *tag)
2505 {
2506         struct promotenode *snap;
2507
2508         if (l == NULL || !list_link_active(&l->list_head))
2509                 return;
2510
2511         while ((snap = list_tail(l)) != NULL) {
2512                 list_remove(l, snap);
2513                 dsl_dataset_rele(snap->ds, tag);
2514                 kmem_free(snap, sizeof (*snap));
2515         }
2516         list_destroy(l);
2517 }
2518
2519 static int
2520 promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp, void *tag)
2521 {
2522         int error;
2523         dsl_dir_t *dd;
2524         struct promotenode *snap;
2525
2526         error = dsl_dataset_hold(dp, ddpa->ddpa_clonename, tag,
2527             &ddpa->ddpa_clone);
2528         if (error != 0)
2529                 return (error);
2530         dd = ddpa->ddpa_clone->ds_dir;
2531
2532         if (dsl_dataset_is_snapshot(ddpa->ddpa_clone) ||
2533             !dsl_dir_is_clone(dd)) {
2534                 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2535                 return (SET_ERROR(EINVAL));
2536         }
2537
2538         error = snaplist_make(dp, 0, dd->dd_phys->dd_origin_obj,
2539             &ddpa->shared_snaps, tag);
2540         if (error != 0)
2541                 goto out;
2542
2543         error = snaplist_make(dp, 0, ddpa->ddpa_clone->ds_object,
2544             &ddpa->clone_snaps, tag);
2545         if (error != 0)
2546                 goto out;
2547
2548         snap = list_head(&ddpa->shared_snaps);
2549         ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2550         error = snaplist_make(dp, dd->dd_phys->dd_origin_obj,
2551             snap->ds->ds_dir->dd_phys->dd_head_dataset_obj,
2552             &ddpa->origin_snaps, tag);
2553         if (error != 0)
2554                 goto out;
2555
2556         if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2557                 error = dsl_dataset_hold_obj(dp,
2558                     snap->ds->ds_dir->dd_phys->dd_origin_obj,
2559                     tag, &ddpa->origin_origin);
2560                 if (error != 0)
2561                         goto out;
2562         }
2563 out:
2564         if (error != 0)
2565                 promote_rele(ddpa, tag);
2566         return (error);
2567 }
2568
2569 static void
2570 promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag)
2571 {
2572         snaplist_destroy(&ddpa->shared_snaps, tag);
2573         snaplist_destroy(&ddpa->clone_snaps, tag);
2574         snaplist_destroy(&ddpa->origin_snaps, tag);
2575         if (ddpa->origin_origin != NULL)
2576                 dsl_dataset_rele(ddpa->origin_origin, tag);
2577         dsl_dataset_rele(ddpa->ddpa_clone, tag);
2578 }
2579
2580 /*
2581  * Promote a clone.
2582  *
2583  * If it fails due to a conflicting snapshot name, "conflsnap" will be filled
2584  * in with the name.  (It must be at least MAXNAMELEN bytes long.)
2585  */
2586 int
2587 dsl_dataset_promote(const char *name, char *conflsnap)
2588 {
2589         dsl_dataset_promote_arg_t ddpa = { 0 };
2590         uint64_t numsnaps;
2591         int error;
2592         objset_t *os;
2593
2594         /*
2595          * We will modify space proportional to the number of
2596          * snapshots.  Compute numsnaps.
2597          */
2598         error = dmu_objset_hold(name, FTAG, &os);
2599         if (error != 0)
2600                 return (error);
2601         error = zap_count(dmu_objset_pool(os)->dp_meta_objset,
2602             dmu_objset_ds(os)->ds_phys->ds_snapnames_zapobj, &numsnaps);
2603         dmu_objset_rele(os, FTAG);
2604         if (error != 0)
2605                 return (error);
2606
2607         ddpa.ddpa_clonename = name;
2608         ddpa.err_ds = conflsnap;
2609         ddpa.cr = CRED();
2610
2611         return (dsl_sync_task(name, dsl_dataset_promote_check,
2612             dsl_dataset_promote_sync, &ddpa,
2613             2 + numsnaps, ZFS_SPACE_CHECK_RESERVED));
2614 }
2615
2616 int
2617 dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
2618     dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx)
2619 {
2620         int64_t unused_refres_delta;
2621
2622         /* they should both be heads */
2623         if (dsl_dataset_is_snapshot(clone) ||
2624             dsl_dataset_is_snapshot(origin_head))
2625                 return (SET_ERROR(EINVAL));
2626
2627         /* if we are not forcing, the branch point should be just before them */
2628         if (!force && clone->ds_prev != origin_head->ds_prev)
2629                 return (SET_ERROR(EINVAL));
2630
2631         /* clone should be the clone (unless they are unrelated) */
2632         if (clone->ds_prev != NULL &&
2633             clone->ds_prev != clone->ds_dir->dd_pool->dp_origin_snap &&
2634             origin_head->ds_dir != clone->ds_prev->ds_dir)
2635                 return (SET_ERROR(EINVAL));
2636
2637         /* the clone should be a child of the origin */
2638         if (clone->ds_dir->dd_parent != origin_head->ds_dir)
2639                 return (SET_ERROR(EINVAL));
2640
2641         /* origin_head shouldn't be modified unless 'force' */
2642         if (!force &&
2643             dsl_dataset_modified_since_snap(origin_head, origin_head->ds_prev))
2644                 return (SET_ERROR(ETXTBSY));
2645
2646         /* origin_head should have no long holds (e.g. is not mounted) */
2647         if (dsl_dataset_handoff_check(origin_head, owner, tx))
2648                 return (SET_ERROR(EBUSY));
2649
2650         /* check amount of any unconsumed refreservation */
2651         unused_refres_delta =
2652             (int64_t)MIN(origin_head->ds_reserved,
2653             origin_head->ds_phys->ds_unique_bytes) -
2654             (int64_t)MIN(origin_head->ds_reserved,
2655             clone->ds_phys->ds_unique_bytes);
2656
2657         if (unused_refres_delta > 0 &&
2658             unused_refres_delta >
2659             dsl_dir_space_available(origin_head->ds_dir, NULL, 0, TRUE))
2660                 return (SET_ERROR(ENOSPC));
2661
2662         /* clone can't be over the head's refquota */
2663         if (origin_head->ds_quota != 0 &&
2664             clone->ds_phys->ds_referenced_bytes > origin_head->ds_quota)
2665                 return (SET_ERROR(EDQUOT));
2666
2667         return (0);
2668 }
2669
2670 void
2671 dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
2672     dsl_dataset_t *origin_head, dmu_tx_t *tx)
2673 {
2674         dsl_pool_t *dp = dmu_tx_pool(tx);
2675         int64_t unused_refres_delta;
2676
2677         ASSERT(clone->ds_reserved == 0);
2678         ASSERT(origin_head->ds_quota == 0 ||
2679             clone->ds_phys->ds_unique_bytes <= origin_head->ds_quota);
2680         ASSERT3P(clone->ds_prev, ==, origin_head->ds_prev);
2681
2682         dmu_buf_will_dirty(clone->ds_dbuf, tx);
2683         dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
2684
2685         if (clone->ds_objset != NULL) {
2686                 dmu_objset_evict(clone->ds_objset);
2687                 clone->ds_objset = NULL;
2688         }
2689
2690         if (origin_head->ds_objset != NULL) {
2691                 dmu_objset_evict(origin_head->ds_objset);
2692                 origin_head->ds_objset = NULL;
2693         }
2694
2695         unused_refres_delta =
2696             (int64_t)MIN(origin_head->ds_reserved,
2697             origin_head->ds_phys->ds_unique_bytes) -
2698             (int64_t)MIN(origin_head->ds_reserved,
2699             clone->ds_phys->ds_unique_bytes);
2700
2701         /*
2702          * Reset origin's unique bytes, if it exists.
2703          */
2704         if (clone->ds_prev) {
2705                 dsl_dataset_t *origin = clone->ds_prev;
2706                 uint64_t comp, uncomp;
2707
2708                 dmu_buf_will_dirty(origin->ds_dbuf, tx);
2709                 dsl_deadlist_space_range(&clone->ds_deadlist,
2710                     origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2711                     &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
2712         }
2713
2714         /* swap blkptrs */
2715         {
2716                 blkptr_t tmp;
2717                 tmp = origin_head->ds_phys->ds_bp;
2718                 origin_head->ds_phys->ds_bp = clone->ds_phys->ds_bp;
2719                 clone->ds_phys->ds_bp = tmp;
2720         }
2721
2722         /* set dd_*_bytes */
2723         {
2724                 int64_t dused, dcomp, duncomp;
2725                 uint64_t cdl_used, cdl_comp, cdl_uncomp;
2726                 uint64_t odl_used, odl_comp, odl_uncomp;
2727
2728                 ASSERT3U(clone->ds_dir->dd_phys->
2729                     dd_used_breakdown[DD_USED_SNAP], ==, 0);
2730
2731                 dsl_deadlist_space(&clone->ds_deadlist,
2732                     &cdl_used, &cdl_comp, &cdl_uncomp);
2733                 dsl_deadlist_space(&origin_head->ds_deadlist,
2734                     &odl_used, &odl_comp, &odl_uncomp);
2735
2736                 dused = clone->ds_phys->ds_referenced_bytes + cdl_used -
2737                     (origin_head->ds_phys->ds_referenced_bytes + odl_used);
2738                 dcomp = clone->ds_phys->ds_compressed_bytes + cdl_comp -
2739                     (origin_head->ds_phys->ds_compressed_bytes + odl_comp);
2740                 duncomp = clone->ds_phys->ds_uncompressed_bytes +
2741                     cdl_uncomp -
2742                     (origin_head->ds_phys->ds_uncompressed_bytes + odl_uncomp);
2743
2744                 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_HEAD,
2745                     dused, dcomp, duncomp, tx);
2746                 dsl_dir_diduse_space(clone->ds_dir, DD_USED_HEAD,
2747                     -dused, -dcomp, -duncomp, tx);
2748
2749                 /*
2750                  * The difference in the space used by snapshots is the
2751                  * difference in snapshot space due to the head's
2752                  * deadlist (since that's the only thing that's
2753                  * changing that affects the snapused).
2754                  */
2755                 dsl_deadlist_space_range(&clone->ds_deadlist,
2756                     origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2757                     &cdl_used, &cdl_comp, &cdl_uncomp);
2758                 dsl_deadlist_space_range(&origin_head->ds_deadlist,
2759                     origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2760                     &odl_used, &odl_comp, &odl_uncomp);
2761                 dsl_dir_transfer_space(origin_head->ds_dir, cdl_used - odl_used,
2762                     DD_USED_HEAD, DD_USED_SNAP, tx);
2763         }
2764
2765         /* swap ds_*_bytes */
2766         SWITCH64(origin_head->ds_phys->ds_referenced_bytes,
2767             clone->ds_phys->ds_referenced_bytes);
2768         SWITCH64(origin_head->ds_phys->ds_compressed_bytes,
2769             clone->ds_phys->ds_compressed_bytes);
2770         SWITCH64(origin_head->ds_phys->ds_uncompressed_bytes,
2771             clone->ds_phys->ds_uncompressed_bytes);
2772         SWITCH64(origin_head->ds_phys->ds_unique_bytes,
2773             clone->ds_phys->ds_unique_bytes);
2774
2775         /* apply any parent delta for change in unconsumed refreservation */
2776         dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_REFRSRV,
2777             unused_refres_delta, 0, 0, tx);
2778
2779         /*
2780          * Swap deadlists.
2781          */
2782         dsl_deadlist_close(&clone->ds_deadlist);
2783         dsl_deadlist_close(&origin_head->ds_deadlist);
2784         SWITCH64(origin_head->ds_phys->ds_deadlist_obj,
2785             clone->ds_phys->ds_deadlist_obj);
2786         dsl_deadlist_open(&clone->ds_deadlist, dp->dp_meta_objset,
2787             clone->ds_phys->ds_deadlist_obj);
2788         dsl_deadlist_open(&origin_head->ds_deadlist, dp->dp_meta_objset,
2789             origin_head->ds_phys->ds_deadlist_obj);
2790
2791         dsl_scan_ds_clone_swapped(origin_head, clone, tx);
2792
2793         spa_history_log_internal_ds(clone, "clone swap", tx,
2794             "parent=%s", origin_head->ds_dir->dd_myname);
2795 }
2796
2797 /*
2798  * Given a pool name and a dataset object number in that pool,
2799  * return the name of that dataset.
2800  */
2801 int
2802 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
2803 {
2804         dsl_pool_t *dp;
2805         dsl_dataset_t *ds;
2806         int error;
2807
2808         error = dsl_pool_hold(pname, FTAG, &dp);
2809         if (error != 0)
2810                 return (error);
2811
2812         error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
2813         if (error == 0) {
2814                 dsl_dataset_name(ds, buf);
2815                 dsl_dataset_rele(ds, FTAG);
2816         }
2817         dsl_pool_rele(dp, FTAG);
2818
2819         return (error);
2820 }
2821
2822 int
2823 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
2824     uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
2825 {
2826         int error = 0;
2827
2828         ASSERT3S(asize, >, 0);
2829
2830         /*
2831          * *ref_rsrv is the portion of asize that will come from any
2832          * unconsumed refreservation space.
2833          */
2834         *ref_rsrv = 0;
2835
2836         mutex_enter(&ds->ds_lock);
2837         /*
2838          * Make a space adjustment for reserved bytes.
2839          */
2840         if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
2841                 ASSERT3U(*used, >=,
2842                     ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2843                 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2844                 *ref_rsrv =
2845                     asize - MIN(asize, parent_delta(ds, asize + inflight));
2846         }
2847
2848         if (!check_quota || ds->ds_quota == 0) {
2849                 mutex_exit(&ds->ds_lock);
2850                 return (0);
2851         }
2852         /*
2853          * If they are requesting more space, and our current estimate
2854          * is over quota, they get to try again unless the actual
2855          * on-disk is over quota and there are no pending changes (which
2856          * may free up space for us).
2857          */
2858         if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
2859                 if (inflight > 0 ||
2860                     ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
2861                         error = SET_ERROR(ERESTART);
2862                 else
2863                         error = SET_ERROR(EDQUOT);
2864         }
2865         mutex_exit(&ds->ds_lock);
2866
2867         return (error);
2868 }
2869
2870 typedef struct dsl_dataset_set_qr_arg {
2871         const char *ddsqra_name;
2872         zprop_source_t ddsqra_source;
2873         uint64_t ddsqra_value;
2874 } dsl_dataset_set_qr_arg_t;
2875
2876
2877 /* ARGSUSED */
2878 static int
2879 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
2880 {
2881         dsl_dataset_set_qr_arg_t *ddsqra = arg;
2882         dsl_pool_t *dp = dmu_tx_pool(tx);
2883         dsl_dataset_t *ds;
2884         int error;
2885         uint64_t newval;
2886
2887         if (spa_version(dp->dp_spa) < SPA_VERSION_REFQUOTA)
2888                 return (SET_ERROR(ENOTSUP));
2889
2890         error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2891         if (error != 0)
2892                 return (error);
2893
2894         if (dsl_dataset_is_snapshot(ds)) {
2895                 dsl_dataset_rele(ds, FTAG);
2896                 return (SET_ERROR(EINVAL));
2897         }
2898
2899         error = dsl_prop_predict(ds->ds_dir,
2900             zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2901             ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2902         if (error != 0) {
2903                 dsl_dataset_rele(ds, FTAG);
2904                 return (error);
2905         }
2906
2907         if (newval == 0) {
2908                 dsl_dataset_rele(ds, FTAG);
2909                 return (0);
2910         }
2911
2912         if (newval < ds->ds_phys->ds_referenced_bytes ||
2913             newval < ds->ds_reserved) {
2914                 dsl_dataset_rele(ds, FTAG);
2915                 return (SET_ERROR(ENOSPC));
2916         }
2917
2918         dsl_dataset_rele(ds, FTAG);
2919         return (0);
2920 }
2921
2922 static void
2923 dsl_dataset_set_refquota_sync(void *arg, dmu_tx_t *tx)
2924 {
2925         dsl_dataset_set_qr_arg_t *ddsqra = arg;
2926         dsl_pool_t *dp = dmu_tx_pool(tx);
2927         dsl_dataset_t *ds;
2928         uint64_t newval;
2929
2930         VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2931
2932         dsl_prop_set_sync_impl(ds,
2933             zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2934             ddsqra->ddsqra_source, sizeof (ddsqra->ddsqra_value), 1,
2935             &ddsqra->ddsqra_value, tx);
2936
2937         VERIFY0(dsl_prop_get_int_ds(ds,
2938             zfs_prop_to_name(ZFS_PROP_REFQUOTA), &newval));
2939
2940         if (ds->ds_quota != newval) {
2941                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2942                 ds->ds_quota = newval;
2943         }
2944         dsl_dataset_rele(ds, FTAG);
2945 }
2946
2947 int
2948 dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
2949     uint64_t refquota)
2950 {
2951         dsl_dataset_set_qr_arg_t ddsqra;
2952
2953         ddsqra.ddsqra_name = dsname;
2954         ddsqra.ddsqra_source = source;
2955         ddsqra.ddsqra_value = refquota;
2956
2957         return (dsl_sync_task(dsname, dsl_dataset_set_refquota_check,
2958             dsl_dataset_set_refquota_sync, &ddsqra, 0, ZFS_SPACE_CHECK_NONE));
2959 }
2960
2961 static int
2962 dsl_dataset_set_refreservation_check(void *arg, dmu_tx_t *tx)
2963 {
2964         dsl_dataset_set_qr_arg_t *ddsqra = arg;
2965         dsl_pool_t *dp = dmu_tx_pool(tx);
2966         dsl_dataset_t *ds;
2967         int error;
2968         uint64_t newval, unique;
2969
2970         if (spa_version(dp->dp_spa) < SPA_VERSION_REFRESERVATION)
2971                 return (SET_ERROR(ENOTSUP));
2972
2973         error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2974         if (error != 0)
2975                 return (error);
2976
2977         if (dsl_dataset_is_snapshot(ds)) {
2978                 dsl_dataset_rele(ds, FTAG);
2979                 return (SET_ERROR(EINVAL));
2980         }
2981
2982         error = dsl_prop_predict(ds->ds_dir,
2983             zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2984             ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2985         if (error != 0) {
2986                 dsl_dataset_rele(ds, FTAG);
2987                 return (error);
2988         }
2989
2990         /*
2991          * If we are doing the preliminary check in open context, the
2992          * space estimates may be inaccurate.
2993          */
2994         if (!dmu_tx_is_syncing(tx)) {
2995                 dsl_dataset_rele(ds, FTAG);
2996                 return (0);
2997         }
2998
2999         mutex_enter(&ds->ds_lock);
3000         if (!DS_UNIQUE_IS_ACCURATE(ds))
3001                 dsl_dataset_recalc_head_uniq(ds);
3002         unique = ds->ds_phys->ds_unique_bytes;
3003         mutex_exit(&ds->ds_lock);
3004
3005         if (MAX(unique, newval) > MAX(unique, ds->ds_reserved)) {
3006                 uint64_t delta = MAX(unique, newval) -
3007                     MAX(unique, ds->ds_reserved);
3008
3009                 if (delta >
3010                     dsl_dir_space_available(ds->ds_dir, NULL, 0, B_TRUE) ||
3011                     (ds->ds_quota > 0 && newval > ds->ds_quota)) {
3012                         dsl_dataset_rele(ds, FTAG);
3013                         return (SET_ERROR(ENOSPC));
3014                 }
3015         }
3016
3017         dsl_dataset_rele(ds, FTAG);
3018         return (0);
3019 }
3020
3021 void
3022 dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
3023     zprop_source_t source, uint64_t value, dmu_tx_t *tx)
3024 {
3025         uint64_t newval;
3026         uint64_t unique;
3027         int64_t delta;
3028
3029         dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
3030             source, sizeof (value), 1, &value, tx);
3031
3032         VERIFY0(dsl_prop_get_int_ds(ds,
3033             zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &newval));
3034
3035         dmu_buf_will_dirty(ds->ds_dbuf, tx);
3036         mutex_enter(&ds->ds_dir->dd_lock);
3037         mutex_enter(&ds->ds_lock);
3038         ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3039         unique = ds->ds_phys->ds_unique_bytes;
3040         delta = MAX(0, (int64_t)(newval - unique)) -
3041             MAX(0, (int64_t)(ds->ds_reserved - unique));
3042         ds->ds_reserved = newval;
3043         mutex_exit(&ds->ds_lock);
3044
3045         dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3046         mutex_exit(&ds->ds_dir->dd_lock);
3047 }
3048
3049 static void
3050 dsl_dataset_set_refreservation_sync(void *arg, dmu_tx_t *tx)
3051 {
3052         dsl_dataset_set_qr_arg_t *ddsqra = arg;
3053         dsl_pool_t *dp = dmu_tx_pool(tx);
3054         dsl_dataset_t *ds;
3055
3056         VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
3057         dsl_dataset_set_refreservation_sync_impl(ds,
3058             ddsqra->ddsqra_source, ddsqra->ddsqra_value, tx);
3059         dsl_dataset_rele(ds, FTAG);
3060 }
3061
3062 int
3063 dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
3064     uint64_t refreservation)
3065 {
3066         dsl_dataset_set_qr_arg_t ddsqra;
3067
3068         ddsqra.ddsqra_name = dsname;
3069         ddsqra.ddsqra_source = source;
3070         ddsqra.ddsqra_value = refreservation;
3071
3072         return (dsl_sync_task(dsname, dsl_dataset_set_refreservation_check,
3073             dsl_dataset_set_refreservation_sync, &ddsqra,
3074             0, ZFS_SPACE_CHECK_NONE));
3075 }
3076
3077 /*
3078  * Return (in *usedp) the amount of space written in new that is not
3079  * present in oldsnap.  New may be a snapshot or the head.  Old must be
3080  * a snapshot before new, in new's filesystem (or its origin).  If not then
3081  * fail and return EINVAL.
3082  *
3083  * The written space is calculated by considering two components:  First, we
3084  * ignore any freed space, and calculate the written as new's used space
3085  * minus old's used space.  Next, we add in the amount of space that was freed
3086  * between the two snapshots, thus reducing new's used space relative to old's.
3087  * Specifically, this is the space that was born before old->ds_creation_txg,
3088  * and freed before new (ie. on new's deadlist or a previous deadlist).
3089  *
3090  * space freed                         [---------------------]
3091  * snapshots                       ---O-------O--------O-------O------
3092  *                                         oldsnap            new
3093  */
3094 int
3095 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
3096     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
3097 {
3098         int err = 0;
3099         uint64_t snapobj;
3100         dsl_pool_t *dp = new->ds_dir->dd_pool;
3101
3102         ASSERT(dsl_pool_config_held(dp));
3103
3104         *usedp = 0;
3105         *usedp += new->ds_phys->ds_referenced_bytes;
3106         *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
3107
3108         *compp = 0;
3109         *compp += new->ds_phys->ds_compressed_bytes;
3110         *compp -= oldsnap->ds_phys->ds_compressed_bytes;
3111
3112         *uncompp = 0;
3113         *uncompp += new->ds_phys->ds_uncompressed_bytes;
3114         *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
3115
3116         snapobj = new->ds_object;
3117         while (snapobj != oldsnap->ds_object) {
3118                 dsl_dataset_t *snap;
3119                 uint64_t used, comp, uncomp;
3120
3121                 if (snapobj == new->ds_object) {
3122                         snap = new;
3123                 } else {
3124                         err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
3125                         if (err != 0)
3126                                 break;
3127                 }
3128
3129                 if (snap->ds_phys->ds_prev_snap_txg ==
3130                     oldsnap->ds_phys->ds_creation_txg) {
3131                         /*
3132                          * The blocks in the deadlist can not be born after
3133                          * ds_prev_snap_txg, so get the whole deadlist space,
3134                          * which is more efficient (especially for old-format
3135                          * deadlists).  Unfortunately the deadlist code
3136                          * doesn't have enough information to make this
3137                          * optimization itself.
3138                          */
3139                         dsl_deadlist_space(&snap->ds_deadlist,
3140                             &used, &comp, &uncomp);
3141                 } else {
3142                         dsl_deadlist_space_range(&snap->ds_deadlist,
3143                             0, oldsnap->ds_phys->ds_creation_txg,
3144                             &used, &comp, &uncomp);
3145                 }
3146                 *usedp += used;
3147                 *compp += comp;
3148                 *uncompp += uncomp;
3149
3150                 /*
3151                  * If we get to the beginning of the chain of snapshots
3152                  * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
3153                  * was not a snapshot of/before new.
3154                  */
3155                 snapobj = snap->ds_phys->ds_prev_snap_obj;
3156                 if (snap != new)
3157                         dsl_dataset_rele(snap, FTAG);
3158                 if (snapobj == 0) {
3159                         err = SET_ERROR(EINVAL);
3160                         break;
3161                 }
3162
3163         }
3164         return (err);
3165 }
3166
3167 /*
3168  * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
3169  * lastsnap, and all snapshots in between are deleted.
3170  *
3171  * blocks that would be freed            [---------------------------]
3172  * snapshots                       ---O-------O--------O-------O--------O
3173  *                                        firstsnap        lastsnap
3174  *
3175  * This is the set of blocks that were born after the snap before firstsnap,
3176  * (birth > firstsnap->prev_snap_txg) and died before the snap after the
3177  * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
3178  * We calculate this by iterating over the relevant deadlists (from the snap
3179  * after lastsnap, backward to the snap after firstsnap), summing up the
3180  * space on the deadlist that was born after the snap before firstsnap.
3181  */
3182 int
3183 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
3184     dsl_dataset_t *lastsnap,
3185     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
3186 {
3187         int err = 0;
3188         uint64_t snapobj;
3189         dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
3190
3191         ASSERT(dsl_dataset_is_snapshot(firstsnap));
3192         ASSERT(dsl_dataset_is_snapshot(lastsnap));
3193
3194         /*
3195          * Check that the snapshots are in the same dsl_dir, and firstsnap
3196          * is before lastsnap.
3197          */
3198         if (firstsnap->ds_dir != lastsnap->ds_dir ||
3199             firstsnap->ds_phys->ds_creation_txg >
3200             lastsnap->ds_phys->ds_creation_txg)
3201                 return (SET_ERROR(EINVAL));
3202
3203         *usedp = *compp = *uncompp = 0;
3204
3205         snapobj = lastsnap->ds_phys->ds_next_snap_obj;
3206         while (snapobj != firstsnap->ds_object) {
3207                 dsl_dataset_t *ds;
3208                 uint64_t used, comp, uncomp;
3209
3210                 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
3211                 if (err != 0)
3212                         break;
3213
3214                 dsl_deadlist_space_range(&ds->ds_deadlist,
3215                     firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3216                     &used, &comp, &uncomp);
3217                 *usedp += used;
3218                 *compp += comp;
3219                 *uncompp += uncomp;
3220
3221                 snapobj = ds->ds_phys->ds_prev_snap_obj;
3222                 ASSERT3U(snapobj, !=, 0);
3223                 dsl_dataset_rele(ds, FTAG);
3224         }
3225         return (err);
3226 }
3227
3228 /*
3229  * Return TRUE if 'earlier' is an earlier snapshot in 'later's timeline.
3230  * For example, they could both be snapshots of the same filesystem, and
3231  * 'earlier' is before 'later'.  Or 'earlier' could be the origin of
3232  * 'later's filesystem.  Or 'earlier' could be an older snapshot in the origin's
3233  * filesystem.  Or 'earlier' could be the origin's origin.
3234  *
3235  * If non-zero, earlier_txg is used instead of earlier's ds_creation_txg.
3236  */
3237 boolean_t
3238 dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier,
3239         uint64_t earlier_txg)
3240 {
3241         dsl_pool_t *dp = later->ds_dir->dd_pool;
3242         int error;
3243         boolean_t ret;
3244
3245         ASSERT(dsl_pool_config_held(dp));
3246         ASSERT(dsl_dataset_is_snapshot(earlier) || earlier_txg != 0);
3247
3248         if (earlier_txg == 0)
3249                 earlier_txg = earlier->ds_phys->ds_creation_txg;
3250
3251         if (dsl_dataset_is_snapshot(later) &&
3252             earlier_txg >= later->ds_phys->ds_creation_txg)
3253                 return (B_FALSE);
3254
3255         if (later->ds_dir == earlier->ds_dir)
3256                 return (B_TRUE);
3257         if (!dsl_dir_is_clone(later->ds_dir))
3258                 return (B_FALSE);
3259
3260         if (later->ds_dir->dd_phys->dd_origin_obj == earlier->ds_object)
3261                 return (B_TRUE);
3262         dsl_dataset_t *origin;
3263         error = dsl_dataset_hold_obj(dp,
3264             later->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin);
3265         if (error != 0)
3266                 return (B_FALSE);
3267         ret = dsl_dataset_is_before(origin, earlier, earlier_txg);
3268         dsl_dataset_rele(origin, FTAG);
3269         return (ret);
3270 }
3271
3272
3273 void
3274 dsl_dataset_zapify(dsl_dataset_t *ds, dmu_tx_t *tx)
3275 {
3276         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3277         dmu_object_zapify(mos, ds->ds_object, DMU_OT_DSL_DATASET, tx);
3278 }