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) 2011, 2016 by Delphix. All rights reserved.
  25  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
  26  * Copyright (c) 2014 RackTop Systems.
  27  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  28  * Copyright (c) 2014 Integros [integros.com]
  29  * Copyright 2016, OmniTI Computer Consulting, Inc. All rights reserved.
  30  */
  31
  32 #include <sys/dmu_objset.h>
  33 #include <sys/dsl_dataset.h>
  34 #include <sys/dsl_dir.h>
  35 #include <sys/dsl_prop.h>
  36 #include <sys/dsl_synctask.h>
  37 #include <sys/dmu_traverse.h>
  38 #include <sys/dmu_impl.h>
  39 #include <sys/dmu_send.h>
  40 #include <sys/dmu_tx.h>
  41 #include <sys/arc.h>
  42 #include <sys/zio.h>
  43 #include <sys/zap.h>
  44 #include <sys/zfeature.h>
  45 #include <sys/unique.h>
  46 #include <sys/zfs_context.h>
  47 #include <sys/zfs_ioctl.h>
  48 #include <sys/spa.h>
  49 #include <sys/zfs_znode.h>
  50 #include <sys/zfs_onexit.h>
  51 #include <sys/zvol.h>
  52 #include <sys/dsl_scan.h>
  53 #include <sys/dsl_deadlist.h>
  54 #include <sys/dsl_destroy.h>
  55 #include <sys/dsl_userhold.h>
  56 #include <sys/dsl_bookmark.h>
  57 #include <sys/dmu_send.h>
  58 #include <sys/zio_checksum.h>
  59 #include <sys/zio_compress.h>
  60 #include <zfs_fletcher.h>
  61
  62 SYSCTL_DECL(_vfs_zfs);
  63
  64 /*
  65  * The SPA supports block sizes up to 16MB.  However, very large blocks
  66  * can have an impact on i/o latency (e.g. tying up a spinning disk for
  67  * ~300ms), and also potentially on the memory allocator.  Therefore,
  68  * we do not allow the recordsize to be set larger than zfs_max_recordsize
  69  * (default 1MB).  Larger blocks can be created by changing this tunable,
  70  * and pools with larger blocks can always be imported and used, regardless
  71  * of this setting.
  72  */
  73 int zfs_max_recordsize = 1 * 1024 * 1024;
  74 SYSCTL_INT(_vfs_zfs, OID_AUTO, max_recordsize, CTLFLAG_RWTUN,
  75     &zfs_max_recordsize, 0,
  76     "Maximum block size.  Expect dragons when tuning this.");
  77
  78 #define SWITCH64(x, y) \
  79         { \
  80                 uint64_t __tmp = (x); \
  81                 (x) = (y); \
  82                 (y) = __tmp; \
  83         }
  84
  85 #define DS_REF_MAX      (1ULL << 62)
  86
  87 extern inline dsl_dataset_phys_t *dsl_dataset_phys(dsl_dataset_t *ds);
  88
  89 extern int spa_asize_inflation;
  90
  91 static zil_header_t zero_zil;
  92
  93 /*
  94  * Figure out how much of this delta should be propogated to the dsl_dir
  95  * layer.  If there's a refreservation, that space has already been
  96  * partially accounted for in our ancestors.
  97  */
  98 static int64_t
  99 parent_delta(dsl_dataset_t *ds, int64_t delta)
 100 {
 101         dsl_dataset_phys_t *ds_phys;
 102         uint64_t old_bytes, new_bytes;
 103
 104         if (ds->ds_reserved == 0)
 105                 return (delta);
 106
 107         ds_phys = dsl_dataset_phys(ds);
 108         old_bytes = MAX(ds_phys->ds_unique_bytes, ds->ds_reserved);
 109         new_bytes = MAX(ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
 110
 111         ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
 112         return (new_bytes - old_bytes);
 113 }
 114
 115 void
 116 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
 117 {
 118         int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
 119         int compressed = BP_GET_PSIZE(bp);
 120         int uncompressed = BP_GET_UCSIZE(bp);
 121         int64_t delta;
 122
 123         dprintf_bp(bp, "ds=%p", ds);
 124
 125         ASSERT(dmu_tx_is_syncing(tx));
 126         /* It could have been compressed away to nothing */
 127         if (BP_IS_HOLE(bp))
 128                 return;
 129         ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
 130         ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
 131         if (ds == NULL) {
 132                 dsl_pool_mos_diduse_space(tx->tx_pool,
 133                     used, compressed, uncompressed);
 134                 return;
 135         }
 136
 137         ASSERT3U(bp->blk_birth, >, dsl_dataset_phys(ds)->ds_prev_snap_txg);
 138         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 139         mutex_enter(&ds->ds_lock);
 140         delta = parent_delta(ds, used);
 141         dsl_dataset_phys(ds)->ds_referenced_bytes += used;
 142         dsl_dataset_phys(ds)->ds_compressed_bytes += compressed;
 143         dsl_dataset_phys(ds)->ds_uncompressed_bytes += uncompressed;
 144         dsl_dataset_phys(ds)->ds_unique_bytes += used;
 145
 146         if (BP_GET_LSIZE(bp) > SPA_OLD_MAXBLOCKSIZE) {
 147                 ds->ds_feature_activation_needed[SPA_FEATURE_LARGE_BLOCKS] =
 148                     B_TRUE;
 149         }
 150
 151         spa_feature_t f = zio_checksum_to_feature(BP_GET_CHECKSUM(bp));
 152         if (f != SPA_FEATURE_NONE)
 153                 ds->ds_feature_activation_needed[f] = B_TRUE;
 154
 155         mutex_exit(&ds->ds_lock);
 156         dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
 157             compressed, uncompressed, tx);
 158         dsl_dir_transfer_space(ds->ds_dir, used - delta,
 159             DD_USED_REFRSRV, DD_USED_HEAD, NULL);
 160 }
 161
 162 int
 163 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
 164     boolean_t async)
 165 {
 166         int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
 167         int compressed = BP_GET_PSIZE(bp);
 168         int uncompressed = BP_GET_UCSIZE(bp);
 169
 170         if (BP_IS_HOLE(bp))
 171                 return (0);
 172
 173         ASSERT(dmu_tx_is_syncing(tx));
 174         ASSERT(bp->blk_birth <= tx->tx_txg);
 175
 176         if (ds == NULL) {
 177                 dsl_free(tx->tx_pool, tx->tx_txg, bp);
 178                 dsl_pool_mos_diduse_space(tx->tx_pool,
 179                     -used, -compressed, -uncompressed);
 180                 return (used);
 181         }
 182         ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
 183
 184         ASSERT(!ds->ds_is_snapshot);
 185         dmu_buf_will_dirty(ds->ds_dbuf, tx);
 186
 187         if (bp->blk_birth > dsl_dataset_phys(ds)->ds_prev_snap_txg) {
 188                 int64_t delta;
 189
 190                 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
 191                 dsl_free(tx->tx_pool, tx->tx_txg, bp);
 192
 193                 mutex_enter(&ds->ds_lock);
 194                 ASSERT(dsl_dataset_phys(ds)->ds_unique_bytes >= used ||
 195                     !DS_UNIQUE_IS_ACCURATE(ds));
 196                 delta = parent_delta(ds, -used);
 197                 dsl_dataset_phys(ds)->ds_unique_bytes -= used;
 198                 mutex_exit(&ds->ds_lock);
 199                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
 200                     delta, -compressed, -uncompressed, tx);
 201                 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
 202                     DD_USED_REFRSRV, DD_USED_HEAD, NULL);
 203         } else {
 204                 dprintf_bp(bp, "putting on dead list: %s", "");
 205                 if (async) {
 206                         /*
 207                          * We are here as part of zio's write done callback,
 208                          * which means we're a zio interrupt thread.  We can't
 209                          * call dsl_deadlist_insert() now because it may block
 210                          * waiting for I/O.  Instead, put bp on the deferred
 211                          * queue and let dsl_pool_sync() finish the job.
 212                          */
 213                         bplist_append(&ds->ds_pending_deadlist, bp);
 214                 } else {
 215                         dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
 216                 }
 217                 ASSERT3U(ds->ds_prev->ds_object, ==,
 218                     dsl_dataset_phys(ds)->ds_prev_snap_obj);
 219                 ASSERT(dsl_dataset_phys(ds->ds_prev)->ds_num_children > 0);
 220                 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
 221                 if (dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj ==
 222                     ds->ds_object && bp->blk_birth >
 223                     dsl_dataset_phys(ds->ds_prev)->ds_prev_snap_txg) {
 224                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
 225                         mutex_enter(&ds->ds_prev->ds_lock);
 226                         dsl_dataset_phys(ds->ds_prev)->ds_unique_bytes += used;
 227                         mutex_exit(&ds->ds_prev->ds_lock);
 228                 }
 229                 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
 230                         dsl_dir_transfer_space(ds->ds_dir, used,
 231                             DD_USED_HEAD, DD_USED_SNAP, tx);
 232                 }
 233         }
 234         mutex_enter(&ds->ds_lock);
 235         ASSERT3U(dsl_dataset_phys(ds)->ds_referenced_bytes, >=, used);
 236         dsl_dataset_phys(ds)->ds_referenced_bytes -= used;
 237         ASSERT3U(dsl_dataset_phys(ds)->ds_compressed_bytes, >=, compressed);
 238         dsl_dataset_phys(ds)->ds_compressed_bytes -= compressed;
 239         ASSERT3U(dsl_dataset_phys(ds)->ds_uncompressed_bytes, >=, uncompressed);
 240         dsl_dataset_phys(ds)->ds_uncompressed_bytes -= uncompressed;
 241         mutex_exit(&ds->ds_lock);
 242
 243         return (used);
 244 }
 245
 246 uint64_t
 247 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
 248 {
 249         uint64_t trysnap = 0;
 250
 251         if (ds == NULL)
 252                 return (0);
 253         /*
 254          * The snapshot creation could fail, but that would cause an
 255          * incorrect FALSE return, which would only result in an
 256          * overestimation of the amount of space that an operation would
 257          * consume, which is OK.
 258          *
 259          * There's also a small window where we could miss a pending
 260          * snapshot, because we could set the sync task in the quiescing
 261          * phase.  So this should only be used as a guess.
 262          */
 263         if (ds->ds_trysnap_txg >
 264             spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
 265                 trysnap = ds->ds_trysnap_txg;
 266         return (MAX(dsl_dataset_phys(ds)->ds_prev_snap_txg, trysnap));
 267 }
 268
 269 boolean_t
 270 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
 271     uint64_t blk_birth)
 272 {
 273         if (blk_birth <= dsl_dataset_prev_snap_txg(ds) ||
 274             (bp != NULL && BP_IS_HOLE(bp)))
 275                 return (B_FALSE);
 276
 277         ddt_prefetch(dsl_dataset_get_spa(ds), bp);
 278
 279         return (B_TRUE);
 280 }
 281
 282 /*
 283  * We have to release the fsid syncronously or we risk that a subsequent
 284  * mount of the same dataset will fail to unique_insert the fsid.  This
 285  * failure would manifest itself as the fsid of this dataset changing
 286  * between mounts which makes NFS clients quite unhappy.
 287  */
 288 static void
 289 dsl_dataset_evict_sync(void *dbu)
 290 {
 291         dsl_dataset_t *ds = dbu;
 292
 293         ASSERT(ds->ds_owner == NULL);
 294
 295         unique_remove(ds->ds_fsid_guid);
 296 }
 297
 298 static void
 299 dsl_dataset_evict_async(void *dbu)
 300 {
 301         dsl_dataset_t *ds = dbu;
 302
 303         ASSERT(ds->ds_owner == NULL);
 304
 305         ds->ds_dbuf = NULL;
 306
 307         if (ds->ds_objset != NULL)
 308                 dmu_objset_evict(ds->ds_objset);
 309
 310         if (ds->ds_prev) {
 311                 dsl_dataset_rele(ds->ds_prev, ds);
 312                 ds->ds_prev = NULL;
 313         }
 314
 315         bplist_destroy(&ds->ds_pending_deadlist);
 316         if (ds->ds_deadlist.dl_os != NULL)
 317                 dsl_deadlist_close(&ds->ds_deadlist);
 318         if (ds->ds_dir)
 319                 dsl_dir_async_rele(ds->ds_dir, ds);
 320
 321         ASSERT(!list_link_active(&ds->ds_synced_link));
 322
 323         list_destroy(&ds->ds_prop_cbs);
 324         if (mutex_owned(&ds->ds_lock))
 325                 mutex_exit(&ds->ds_lock);
 326         mutex_destroy(&ds->ds_lock);
 327         if (mutex_owned(&ds->ds_opening_lock))
 328                 mutex_exit(&ds->ds_opening_lock);
 329         mutex_destroy(&ds->ds_opening_lock);
 330         mutex_destroy(&ds->ds_sendstream_lock);
 331         refcount_destroy(&ds->ds_longholds);
 332         rrw_destroy(&ds->ds_bp_rwlock);
 333
 334         kmem_free(ds, sizeof (dsl_dataset_t));
 335 }
 336
 337 int
 338 dsl_dataset_get_snapname(dsl_dataset_t *ds)
 339 {
 340         dsl_dataset_phys_t *headphys;
 341         int err;
 342         dmu_buf_t *headdbuf;
 343         dsl_pool_t *dp = ds->ds_dir->dd_pool;
 344         objset_t *mos = dp->dp_meta_objset;
 345
 346         if (ds->ds_snapname[0])
 347                 return (0);
 348         if (dsl_dataset_phys(ds)->ds_next_snap_obj == 0)
 349                 return (0);
 350
 351         err = dmu_bonus_hold(mos, dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj,
 352             FTAG, &headdbuf);
 353         if (err != 0)
 354                 return (err);
 355         headphys = headdbuf->db_data;
 356         err = zap_value_search(dp->dp_meta_objset,
 357             headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
 358         dmu_buf_rele(headdbuf, FTAG);
 359         return (err);
 360 }
 361
 362 int
 363 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
 364 {
 365         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 366         uint64_t snapobj = dsl_dataset_phys(ds)->ds_snapnames_zapobj;
 367         matchtype_t mt;
 368         int err;
 369
 370         if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
 371                 mt = MT_FIRST;
 372         else
 373                 mt = MT_EXACT;
 374
 375         err = zap_lookup_norm(mos, snapobj, name, 8, 1,
 376             value, mt, NULL, 0, NULL);
 377         if (err == ENOTSUP && mt == MT_FIRST)
 378                 err = zap_lookup(mos, snapobj, name, 8, 1, value);
 379         return (err);
 380 }
 381
 382 int
 383 dsl_dataset_snap_remove(dsl_dataset_t *ds, const char *name, dmu_tx_t *tx,
 384     boolean_t adj_cnt)
 385 {
 386         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
 387         uint64_t snapobj = dsl_dataset_phys(ds)->ds_snapnames_zapobj;
 388         matchtype_t mt;
 389         int err;
 390
 391         dsl_dir_snap_cmtime_update(ds->ds_dir);
 392
 393         if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
 394                 mt = MT_FIRST;
 395         else
 396                 mt = MT_EXACT;
 397
 398         err = zap_remove_norm(mos, snapobj, name, mt, tx);
 399         if (err == ENOTSUP && mt == MT_FIRST)
 400                 err = zap_remove(mos, snapobj, name, tx);
 401
 402         if (err == 0 && adj_cnt)
 403                 dsl_fs_ss_count_adjust(ds->ds_dir, -1,
 404                     DD_FIELD_SNAPSHOT_COUNT, tx);
 405
 406         return (err);
 407 }
 408
 409 boolean_t
 410 dsl_dataset_try_add_ref(dsl_pool_t *dp, dsl_dataset_t *ds, void *tag)
 411 {
 412         dmu_buf_t *dbuf = ds->ds_dbuf;
 413         boolean_t result = B_FALSE;
 414
 415         if (dbuf != NULL && dmu_buf_try_add_ref(dbuf, dp->dp_meta_objset,
 416             ds->ds_object, DMU_BONUS_BLKID, tag)) {
 417
 418                 if (ds == dmu_buf_get_user(dbuf))
 419                         result = B_TRUE;
 420                 else
 421                         dmu_buf_rele(dbuf, tag);
 422         }
 423
 424         return (result);
 425 }
 426
 427 int
 428 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 429     dsl_dataset_t **dsp)
 430 {
 431         objset_t *mos = dp->dp_meta_objset;
 432         dmu_buf_t *dbuf;
 433         dsl_dataset_t *ds;
 434         int err;
 435         dmu_object_info_t doi;
 436
 437         ASSERT(dsl_pool_config_held(dp));
 438
 439         err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
 440         if (err != 0)
 441                 return (err);
 442
 443         /* Make sure dsobj has the correct object type. */
 444         dmu_object_info_from_db(dbuf, &doi);
 445         if (doi.doi_bonus_type != DMU_OT_DSL_DATASET) {
 446                 dmu_buf_rele(dbuf, tag);
 447                 return (SET_ERROR(EINVAL));
 448         }
 449
 450         ds = dmu_buf_get_user(dbuf);
 451         if (ds == NULL) {
 452                 dsl_dataset_t *winner = NULL;
 453
 454                 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
 455                 ds->ds_dbuf = dbuf;
 456                 ds->ds_object = dsobj;
 457                 ds->ds_is_snapshot = dsl_dataset_phys(ds)->ds_num_children != 0;
 458
 459                 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
 460                 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
 461                 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
 462                 rrw_init(&ds->ds_bp_rwlock, B_FALSE);
 463                 refcount_create(&ds->ds_longholds);
 464
 465                 bplist_create(&ds->ds_pending_deadlist);
 466                 dsl_deadlist_open(&ds->ds_deadlist,
 467                     mos, dsl_dataset_phys(ds)->ds_deadlist_obj);
 468
 469                 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
 470                     offsetof(dmu_sendarg_t, dsa_link));
 471
 472                 list_create(&ds->ds_prop_cbs, sizeof (dsl_prop_cb_record_t),
 473                     offsetof(dsl_prop_cb_record_t, cbr_ds_node));
 474
 475                 if (doi.doi_type == DMU_OTN_ZAP_METADATA) {
 476                         for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
 477                                 if (!(spa_feature_table[f].fi_flags &
 478                                     ZFEATURE_FLAG_PER_DATASET))
 479                                         continue;
 480                                 err = zap_contains(mos, dsobj,
 481                                     spa_feature_table[f].fi_guid);
 482                                 if (err == 0) {
 483                                         ds->ds_feature_inuse[f] = B_TRUE;
 484                                 } else {
 485                                         ASSERT3U(err, ==, ENOENT);
 486                                         err = 0;
 487                                 }
 488                         }
 489                 }
 490
 491                 err = dsl_dir_hold_obj(dp,
 492                     dsl_dataset_phys(ds)->ds_dir_obj, NULL, ds, &ds->ds_dir);
 493                 if (err != 0) {
 494                         mutex_destroy(&ds->ds_lock);
 495                         mutex_destroy(&ds->ds_opening_lock);
 496                         mutex_destroy(&ds->ds_sendstream_lock);
 497                         refcount_destroy(&ds->ds_longholds);
 498                         bplist_destroy(&ds->ds_pending_deadlist);
 499                         dsl_deadlist_close(&ds->ds_deadlist);
 500                         kmem_free(ds, sizeof (dsl_dataset_t));
 501                         dmu_buf_rele(dbuf, tag);
 502                         return (err);
 503                 }
 504
 505                 if (!ds->ds_is_snapshot) {
 506                         ds->ds_snapname[0] = '\0';
 507                         if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
 508                                 err = dsl_dataset_hold_obj(dp,
 509                                     dsl_dataset_phys(ds)->ds_prev_snap_obj,
 510                                     ds, &ds->ds_prev);
 511                         }
 512                         if (doi.doi_type == DMU_OTN_ZAP_METADATA) {
 513                                 int zaperr = zap_lookup(mos, ds->ds_object,
 514                                     DS_FIELD_BOOKMARK_NAMES,
 515                                     sizeof (ds->ds_bookmarks), 1,
 516                                     &ds->ds_bookmarks);
 517                                 if (zaperr != ENOENT)
 518                                         VERIFY0(zaperr);
 519                         }
 520                 } else {
 521                         if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
 522                                 err = dsl_dataset_get_snapname(ds);
 523                         if (err == 0 &&
 524                             dsl_dataset_phys(ds)->ds_userrefs_obj != 0) {
 525                                 err = zap_count(
 526                                     ds->ds_dir->dd_pool->dp_meta_objset,
 527                                     dsl_dataset_phys(ds)->ds_userrefs_obj,
 528                                     &ds->ds_userrefs);
 529                         }
 530                 }
 531
 532                 if (err == 0 && !ds->ds_is_snapshot) {
 533                         err = dsl_prop_get_int_ds(ds,
 534                             zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
 535                             &ds->ds_reserved);
 536                         if (err == 0) {
 537                                 err = dsl_prop_get_int_ds(ds,
 538                                     zfs_prop_to_name(ZFS_PROP_REFQUOTA),
 539                                     &ds->ds_quota);
 540                         }
 541                 } else {
 542                         ds->ds_reserved = ds->ds_quota = 0;
 543                 }
 544
 545                 dmu_buf_init_user(&ds->ds_dbu, dsl_dataset_evict_sync,
 546                     dsl_dataset_evict_async, &ds->ds_dbuf);
 547                 if (err == 0)
 548                         winner = dmu_buf_set_user_ie(dbuf, &ds->ds_dbu);
 549
 550                 if (err != 0 || winner != NULL) {
 551                         bplist_destroy(&ds->ds_pending_deadlist);
 552                         dsl_deadlist_close(&ds->ds_deadlist);
 553                         if (ds->ds_prev)
 554                                 dsl_dataset_rele(ds->ds_prev, ds);
 555                         dsl_dir_rele(ds->ds_dir, ds);
 556                         mutex_destroy(&ds->ds_lock);
 557                         mutex_destroy(&ds->ds_opening_lock);
 558                         mutex_destroy(&ds->ds_sendstream_lock);
 559                         refcount_destroy(&ds->ds_longholds);
 560                         kmem_free(ds, sizeof (dsl_dataset_t));
 561                         if (err != 0) {
 562                                 dmu_buf_rele(dbuf, tag);
 563                                 return (err);
 564                         }
 565                         ds = winner;
 566                 } else {
 567                         ds->ds_fsid_guid =
 568                             unique_insert(dsl_dataset_phys(ds)->ds_fsid_guid);
 569                         if (ds->ds_fsid_guid !=
 570                             dsl_dataset_phys(ds)->ds_fsid_guid) {
 571                                 zfs_dbgmsg("ds_fsid_guid changed from "
 572                                     "%llx to %llx for pool %s dataset id %llu",
 573                                     (long long)
 574                                     dsl_dataset_phys(ds)->ds_fsid_guid,
 575                                     (long long)ds->ds_fsid_guid,
 576                                     spa_name(dp->dp_spa),
 577                                     dsobj);
 578                         }
 579                 }
 580         }
 581         ASSERT3P(ds->ds_dbuf, ==, dbuf);
 582         ASSERT3P(dsl_dataset_phys(ds), ==, dbuf->db_data);
 583         ASSERT(dsl_dataset_phys(ds)->ds_prev_snap_obj != 0 ||
 584             spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
 585             dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
 586         *dsp = ds;
 587         return (0);
 588 }
 589
 590 int
 591 dsl_dataset_hold(dsl_pool_t *dp, const char *name,
 592     void *tag, dsl_dataset_t **dsp)
 593 {
 594         dsl_dir_t *dd;
 595         const char *snapname;
 596         uint64_t obj;
 597         int err = 0;
 598         dsl_dataset_t *ds;
 599
 600         err = dsl_dir_hold(dp, name, FTAG, &dd, &snapname);
 601         if (err != 0)
 602                 return (err);
 603
 604         ASSERT(dsl_pool_config_held(dp));
 605         obj = dsl_dir_phys(dd)->dd_head_dataset_obj;
 606         if (obj != 0)
 607                 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
 608         else
 609                 err = SET_ERROR(ENOENT);
 610
 611         /* we may be looking for a snapshot */
 612         if (err == 0 && snapname != NULL) {
 613                 dsl_dataset_t *snap_ds;
 614
 615                 if (*snapname++ != '@') {
 616                         dsl_dataset_rele(ds, tag);
 617                         dsl_dir_rele(dd, FTAG);
 618                         return (SET_ERROR(ENOENT));
 619                 }
 620
 621                 dprintf("looking for snapshot '%s'\n", snapname);
 622                 err = dsl_dataset_snap_lookup(ds, snapname, &obj);
 623                 if (err == 0)
 624                         err = dsl_dataset_hold_obj(dp, obj, tag, &snap_ds);
 625                 dsl_dataset_rele(ds, tag);
 626
 627                 if (err == 0) {
 628                         mutex_enter(&snap_ds->ds_lock);
 629                         if (snap_ds->ds_snapname[0] == 0)
 630                                 (void) strlcpy(snap_ds->ds_snapname, snapname,
 631                                     sizeof (snap_ds->ds_snapname));
 632                         mutex_exit(&snap_ds->ds_lock);
 633                         ds = snap_ds;
 634                 }
 635         }
 636         if (err == 0)
 637                 *dsp = ds;
 638         dsl_dir_rele(dd, FTAG);
 639         return (err);
 640 }
 641
 642 int
 643 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj,
 644     void *tag, dsl_dataset_t **dsp)
 645 {
 646         int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
 647         if (err != 0)
 648                 return (err);
 649         if (!dsl_dataset_tryown(*dsp, tag)) {
 650                 dsl_dataset_rele(*dsp, tag);
 651                 *dsp = NULL;
 652                 return (SET_ERROR(EBUSY));
 653         }
 654         return (0);
 655 }
 656
 657 int
 658 dsl_dataset_own(dsl_pool_t *dp, const char *name,
 659     void *tag, dsl_dataset_t **dsp)
 660 {
 661         int err = dsl_dataset_hold(dp, name, tag, dsp);
 662         if (err != 0)
 663                 return (err);
 664         if (!dsl_dataset_tryown(*dsp, tag)) {
 665                 dsl_dataset_rele(*dsp, tag);
 666                 return (SET_ERROR(EBUSY));
 667         }
 668         return (0);
 669 }
 670
 671 /*
 672  * See the comment above dsl_pool_hold() for details.  In summary, a long
 673  * hold is used to prevent destruction of a dataset while the pool hold
 674  * is dropped, allowing other concurrent operations (e.g. spa_sync()).
 675  *
 676  * The dataset and pool must be held when this function is called.  After it
 677  * is called, the pool hold may be released while the dataset is still held
 678  * and accessed.
 679  */
 680 void
 681 dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag)
 682 {
 683         ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
 684         (void) refcount_add(&ds->ds_longholds, tag);
 685 }
 686
 687 void
 688 dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag)
 689 {
 690         (void) refcount_remove(&ds->ds_longholds, tag);
 691 }
 692
 693 /* Return B_TRUE if there are any long holds on this dataset. */
 694 boolean_t
 695 dsl_dataset_long_held(dsl_dataset_t *ds)
 696 {
 697         return (!refcount_is_zero(&ds->ds_longholds));
 698 }
 699
 700 void
 701 dsl_dataset_name(dsl_dataset_t *ds, char *name)
 702 {
 703         if (ds == NULL) {
 704                 (void) strcpy(name, "mos");
 705         } else {
 706                 dsl_dir_name(ds->ds_dir, name);
 707                 VERIFY0(dsl_dataset_get_snapname(ds));
 708                 if (ds->ds_snapname[0]) {
 709                         VERIFY3U(strlcat(name, "@", ZFS_MAX_DATASET_NAME_LEN),
 710                             <, ZFS_MAX_DATASET_NAME_LEN);
 711                         /*
 712                          * We use a "recursive" mutex so that we
 713                          * can call dprintf_ds() with ds_lock held.
 714                          */
 715                         if (!MUTEX_HELD(&ds->ds_lock)) {
 716                                 mutex_enter(&ds->ds_lock);
 717                                 VERIFY3U(strlcat(name, ds->ds_snapname,
 718                                     ZFS_MAX_DATASET_NAME_LEN), <,
 719                                     ZFS_MAX_DATASET_NAME_LEN);
 720                                 mutex_exit(&ds->ds_lock);
 721                         } else {
 722                                 VERIFY3U(strlcat(name, ds->ds_snapname,
 723                                     ZFS_MAX_DATASET_NAME_LEN), <,
 724                                     ZFS_MAX_DATASET_NAME_LEN);
 725                         }
 726                 }
 727         }
 728 }
 729
 730 int
 731 dsl_dataset_namelen(dsl_dataset_t *ds)
 732 {
 733         VERIFY0(dsl_dataset_get_snapname(ds));
 734         mutex_enter(&ds->ds_lock);
 735         int len = dsl_dir_namelen(ds->ds_dir) + 1 + strlen(ds->ds_snapname);
 736         mutex_exit(&ds->ds_lock);
 737         return (len);
 738 }
 739
 740 void
 741 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
 742 {
 743         dmu_buf_rele(ds->ds_dbuf, tag);
 744 }
 745
 746 void
 747 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
 748 {
 749         ASSERT3P(ds->ds_owner, ==, tag);
 750         ASSERT(ds->ds_dbuf != NULL);
 751
 752         mutex_enter(&ds->ds_lock);
 753         ds->ds_owner = NULL;
 754         mutex_exit(&ds->ds_lock);
 755         dsl_dataset_long_rele(ds, tag);
 756         dsl_dataset_rele(ds, tag);
 757 }
 758
 759 boolean_t
 760 dsl_dataset_tryown(dsl_dataset_t *ds, void *tag)
 761 {
 762         boolean_t gotit = FALSE;
 763
 764         ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
 765         mutex_enter(&ds->ds_lock);
 766         if (ds->ds_owner == NULL && !DS_IS_INCONSISTENT(ds)) {
 767                 ds->ds_owner = tag;
 768                 dsl_dataset_long_hold(ds, tag);
 769                 gotit = TRUE;
 770         }
 771         mutex_exit(&ds->ds_lock);
 772         return (gotit);
 773 }
 774
 775 boolean_t
 776 dsl_dataset_has_owner(dsl_dataset_t *ds)
 777 {
 778         boolean_t rv;
 779         mutex_enter(&ds->ds_lock);
 780         rv = (ds->ds_owner != NULL);
 781         mutex_exit(&ds->ds_lock);
 782         return (rv);
 783 }
 784
 785 static void
 786 dsl_dataset_activate_feature(uint64_t dsobj, spa_feature_t f, dmu_tx_t *tx)
 787 {
 788         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 789         objset_t *mos = dmu_tx_pool(tx)->dp_meta_objset;
 790         uint64_t zero = 0;
 791
 792         VERIFY(spa_feature_table[f].fi_flags & ZFEATURE_FLAG_PER_DATASET);
 793
 794         spa_feature_incr(spa, f, tx);
 795         dmu_object_zapify(mos, dsobj, DMU_OT_DSL_DATASET, tx);
 796
 797         VERIFY0(zap_add(mos, dsobj, spa_feature_table[f].fi_guid,
 798             sizeof (zero), 1, &zero, tx));
 799 }
 800
 801 void
 802 dsl_dataset_deactivate_feature(uint64_t dsobj, spa_feature_t f, dmu_tx_t *tx)
 803 {
 804         spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 805         objset_t *mos = dmu_tx_pool(tx)->dp_meta_objset;
 806
 807         VERIFY(spa_feature_table[f].fi_flags & ZFEATURE_FLAG_PER_DATASET);
 808
 809         VERIFY0(zap_remove(mos, dsobj, spa_feature_table[f].fi_guid, tx));
 810         spa_feature_decr(spa, f, tx);
 811 }
 812
 813 uint64_t
 814 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
 815     uint64_t flags, dmu_tx_t *tx)
 816 {
 817         dsl_pool_t *dp = dd->dd_pool;
 818         dmu_buf_t *dbuf;
 819         dsl_dataset_phys_t *dsphys;
 820         uint64_t dsobj;
 821         objset_t *mos = dp->dp_meta_objset;
 822
 823         if (origin == NULL)
 824                 origin = dp->dp_origin_snap;
 825
 826         ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
 827         ASSERT(origin == NULL || dsl_dataset_phys(origin)->ds_num_children > 0);
 828         ASSERT(dmu_tx_is_syncing(tx));
 829         ASSERT(dsl_dir_phys(dd)->dd_head_dataset_obj == 0);
 830
 831         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
 832             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
 833         VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
 834         dmu_buf_will_dirty(dbuf, tx);
 835         dsphys = dbuf->db_data;
 836         bzero(dsphys, sizeof (dsl_dataset_phys_t));
 837         dsphys->ds_dir_obj = dd->dd_object;
 838         dsphys->ds_flags = flags;
 839         dsphys->ds_fsid_guid = unique_create();
 840         do {
 841                 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
 842                     sizeof (dsphys->ds_guid));
 843         } while (dsphys->ds_guid == 0);
 844         dsphys->ds_snapnames_zapobj =
 845             zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
 846             DMU_OT_NONE, 0, tx);
 847         dsphys->ds_creation_time = gethrestime_sec();
 848         dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
 849
 850         if (origin == NULL) {
 851                 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
 852         } else {
 853                 dsl_dataset_t *ohds; /* head of the origin snapshot */
 854
 855                 dsphys->ds_prev_snap_obj = origin->ds_object;
 856                 dsphys->ds_prev_snap_txg =
 857                     dsl_dataset_phys(origin)->ds_creation_txg;
 858                 dsphys->ds_referenced_bytes =
 859                     dsl_dataset_phys(origin)->ds_referenced_bytes;
 860                 dsphys->ds_compressed_bytes =
 861                     dsl_dataset_phys(origin)->ds_compressed_bytes;
 862                 dsphys->ds_uncompressed_bytes =
 863                     dsl_dataset_phys(origin)->ds_uncompressed_bytes;
 864                 rrw_enter(&origin->ds_bp_rwlock, RW_READER, FTAG);
 865                 dsphys->ds_bp = dsl_dataset_phys(origin)->ds_bp;
 866                 rrw_exit(&origin->ds_bp_rwlock, FTAG);
 867
 868                 /*
 869                  * Inherit flags that describe the dataset's contents
 870                  * (INCONSISTENT) or properties (Case Insensitive).
 871                  */
 872                 dsphys->ds_flags |= dsl_dataset_phys(origin)->ds_flags &
 873                     (DS_FLAG_INCONSISTENT | DS_FLAG_CI_DATASET);
 874
 875                 for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
 876                         if (origin->ds_feature_inuse[f])
 877                                 dsl_dataset_activate_feature(dsobj, f, tx);
 878                 }
 879
 880                 dmu_buf_will_dirty(origin->ds_dbuf, tx);
 881                 dsl_dataset_phys(origin)->ds_num_children++;
 882
 883                 VERIFY0(dsl_dataset_hold_obj(dp,
 884                     dsl_dir_phys(origin->ds_dir)->dd_head_dataset_obj,
 885                     FTAG, &ohds));
 886                 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
 887                     dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
 888                 dsl_dataset_rele(ohds, FTAG);
 889
 890                 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
 891                         if (dsl_dataset_phys(origin)->ds_next_clones_obj == 0) {
 892                                 dsl_dataset_phys(origin)->ds_next_clones_obj =
 893                                     zap_create(mos,
 894                                     DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
 895                         }
 896                         VERIFY0(zap_add_int(mos,
 897                             dsl_dataset_phys(origin)->ds_next_clones_obj,
 898                             dsobj, tx));
 899                 }
 900
 901                 dmu_buf_will_dirty(dd->dd_dbuf, tx);
 902                 dsl_dir_phys(dd)->dd_origin_obj = origin->ds_object;
 903                 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
 904                         if (dsl_dir_phys(origin->ds_dir)->dd_clones == 0) {
 905                                 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
 906                                 dsl_dir_phys(origin->ds_dir)->dd_clones =
 907                                     zap_create(mos,
 908                                     DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
 909                         }
 910                         VERIFY0(zap_add_int(mos,
 911                             dsl_dir_phys(origin->ds_dir)->dd_clones,
 912                             dsobj, tx));
 913                 }
 914         }
 915
 916         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
 917                 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
 918
 919         dmu_buf_rele(dbuf, FTAG);
 920
 921         dmu_buf_will_dirty(dd->dd_dbuf, tx);
 922         dsl_dir_phys(dd)->dd_head_dataset_obj = dsobj;
 923
 924         return (dsobj);
 925 }
 926
 927 static void
 928 dsl_dataset_zero_zil(dsl_dataset_t *ds, dmu_tx_t *tx)
 929 {
 930         objset_t *os;
 931
 932         VERIFY0(dmu_objset_from_ds(ds, &os));
 933         if (bcmp(&os->os_zil_header, &zero_zil, sizeof (zero_zil)) != 0) {
 934                 dsl_pool_t *dp = ds->ds_dir->dd_pool;
 935                 zio_t *zio;
 936
 937                 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
 938
 939                 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
 940                 dsl_dataset_sync(ds, zio, tx);
 941                 VERIFY0(zio_wait(zio));
 942
 943                 /* dsl_dataset_sync_done will drop this reference. */
 944                 dmu_buf_add_ref(ds->ds_dbuf, ds);
 945                 dsl_dataset_sync_done(ds, tx);
 946         }
 947 }
 948
 949 uint64_t
 950 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
 951     dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
 952 {
 953         dsl_pool_t *dp = pdd->dd_pool;
 954         uint64_t dsobj, ddobj;
 955         dsl_dir_t *dd;
 956
 957         ASSERT(dmu_tx_is_syncing(tx));
 958         ASSERT(lastname[0] != '@');
 959
 960         ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
 961         VERIFY0(dsl_dir_hold_obj(dp, ddobj, lastname, FTAG, &dd));
 962
 963         dsobj = dsl_dataset_create_sync_dd(dd, origin,
 964             flags & ~DS_CREATE_FLAG_NODIRTY, tx);
 965
 966         dsl_deleg_set_create_perms(dd, tx, cr);
 967
 968         /*
 969          * Since we're creating a new node we know it's a leaf, so we can
 970          * initialize the counts if the limit feature is active.
 971          */
 972         if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_FS_SS_LIMIT)) {
 973                 uint64_t cnt = 0;
 974                 objset_t *os = dd->dd_pool->dp_meta_objset;
 975
 976                 dsl_dir_zapify(dd, tx);
 977                 VERIFY0(zap_add(os, dd->dd_object, DD_FIELD_FILESYSTEM_COUNT,
 978                     sizeof (cnt), 1, &cnt, tx));
 979                 VERIFY0(zap_add(os, dd->dd_object, DD_FIELD_SNAPSHOT_COUNT,
 980                     sizeof (cnt), 1, &cnt, tx));
 981         }
 982
 983         dsl_dir_rele(dd, FTAG);
 984
 985         /*
 986          * If we are creating a clone, make sure we zero out any stale
 987          * data from the origin snapshots zil header.
 988          */
 989         if (origin != NULL && !(flags & DS_CREATE_FLAG_NODIRTY)) {
 990                 dsl_dataset_t *ds;
 991
 992                 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
 993                 dsl_dataset_zero_zil(ds, tx);
 994                 dsl_dataset_rele(ds, FTAG);
 995         }
 996
 997         return (dsobj);
 998 }
 999
1000 #ifdef __FreeBSD__
1001 /* FreeBSD ioctl compat begin */
1002 struct destroyarg {
1003         nvlist_t *nvl;
1004         const char *snapname;
1005 };
1006
1007 static int
1008 dsl_check_snap_cb(const char *name, void *arg)
1009 {
1010         struct destroyarg *da = arg;
1011         dsl_dataset_t *ds;
1012         char *dsname;
1013
1014         dsname = kmem_asprintf("%s@%s", name, da->snapname);
1015         fnvlist_add_boolean(da->nvl, dsname);
1016         kmem_free(dsname, strlen(dsname) + 1);
1017
1018         return (0);
1019 }
1020
1021 int
1022 dmu_get_recursive_snaps_nvl(char *fsname, const char *snapname,
1023     nvlist_t *snaps)
1024 {
1025         struct destroyarg *da;
1026         int err;
1027
1028         da = kmem_zalloc(sizeof (struct destroyarg), KM_SLEEP);
1029         da->nvl = snaps;
1030         da->snapname = snapname;
1031         err = dmu_objset_find(fsname, dsl_check_snap_cb, da,
1032             DS_FIND_CHILDREN);
1033         kmem_free(da, sizeof (struct destroyarg));
1034
1035         return (err);
1036 }
1037 /* FreeBSD ioctl compat end */
1038 #endif /* __FreeBSD__ */
1039
1040 /*
1041  * The unique space in the head dataset can be calculated by subtracting
1042  * the space used in the most recent snapshot, that is still being used
1043  * in this file system, from the space currently in use.  To figure out
1044  * the space in the most recent snapshot still in use, we need to take
1045  * the total space used in the snapshot and subtract out the space that
1046  * has been freed up since the snapshot was taken.
1047  */
1048 void
1049 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1050 {
1051         uint64_t mrs_used;
1052         uint64_t dlused, dlcomp, dluncomp;
1053
1054         ASSERT(!ds->ds_is_snapshot);
1055
1056         if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0)
1057                 mrs_used = dsl_dataset_phys(ds->ds_prev)->ds_referenced_bytes;
1058         else
1059                 mrs_used = 0;
1060
1061         dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1062
1063         ASSERT3U(dlused, <=, mrs_used);
1064         dsl_dataset_phys(ds)->ds_unique_bytes =
1065             dsl_dataset_phys(ds)->ds_referenced_bytes - (mrs_used - dlused);
1066
1067         if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1068             SPA_VERSION_UNIQUE_ACCURATE)
1069                 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1070 }
1071
1072 void
1073 dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
1074     dmu_tx_t *tx)
1075 {
1076         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1077         uint64_t count;
1078         int err;
1079
1080         ASSERT(dsl_dataset_phys(ds)->ds_num_children >= 2);
1081         err = zap_remove_int(mos, dsl_dataset_phys(ds)->ds_next_clones_obj,
1082             obj, tx);
1083         /*
1084          * The err should not be ENOENT, but a bug in a previous version
1085          * of the code could cause upgrade_clones_cb() to not set
1086          * ds_next_snap_obj when it should, leading to a missing entry.
1087          * If we knew that the pool was created after
1088          * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1089          * ENOENT.  However, at least we can check that we don't have
1090          * too many entries in the next_clones_obj even after failing to
1091          * remove this one.
1092          */
1093         if (err != ENOENT)
1094                 VERIFY0(err);
1095         ASSERT0(zap_count(mos, dsl_dataset_phys(ds)->ds_next_clones_obj,
1096             &count));
1097         ASSERT3U(count, <=, dsl_dataset_phys(ds)->ds_num_children - 2);
1098 }
1099
1100
1101 blkptr_t *
1102 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1103 {
1104         return (&dsl_dataset_phys(ds)->ds_bp);
1105 }
1106
1107 spa_t *
1108 dsl_dataset_get_spa(dsl_dataset_t *ds)
1109 {
1110         return (ds->ds_dir->dd_pool->dp_spa);
1111 }
1112
1113 void
1114 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1115 {
1116         dsl_pool_t *dp;
1117
1118         if (ds == NULL) /* this is the meta-objset */
1119                 return;
1120
1121         ASSERT(ds->ds_objset != NULL);
1122
1123         if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0)
1124                 panic("dirtying snapshot!");
1125
1126         /* Must not dirty a dataset in the same txg where it got snapshotted. */
1127         ASSERT3U(tx->tx_txg, >, dsl_dataset_phys(ds)->ds_prev_snap_txg);
1128
1129         dp = ds->ds_dir->dd_pool;
1130         if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
1131                 /* up the hold count until we can be written out */
1132                 dmu_buf_add_ref(ds->ds_dbuf, ds);
1133         }
1134 }
1135
1136 boolean_t
1137 dsl_dataset_is_dirty(dsl_dataset_t *ds)
1138 {
1139         for (int t = 0; t < TXG_SIZE; t++) {
1140                 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
1141                     ds, t))
1142                         return (B_TRUE);
1143         }
1144         return (B_FALSE);
1145 }
1146
1147 static int
1148 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1149 {
1150         uint64_t asize;
1151
1152         if (!dmu_tx_is_syncing(tx))
1153                 return (0);
1154
1155         /*
1156          * If there's an fs-only reservation, any blocks that might become
1157          * owned by the snapshot dataset must be accommodated by space
1158          * outside of the reservation.
1159          */
1160         ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1161         asize = MIN(dsl_dataset_phys(ds)->ds_unique_bytes, ds->ds_reserved);
1162         if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1163                 return (SET_ERROR(ENOSPC));
1164
1165         /*
1166          * Propagate any reserved space for this snapshot to other
1167          * snapshot checks in this sync group.
1168          */
1169         if (asize > 0)
1170                 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1171
1172         return (0);
1173 }
1174
1175 typedef struct dsl_dataset_snapshot_arg {
1176         nvlist_t *ddsa_snaps;
1177         nvlist_t *ddsa_props;
1178         nvlist_t *ddsa_errors;
1179         cred_t *ddsa_cr;
1180 } dsl_dataset_snapshot_arg_t;
1181
1182 int
1183 dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
1184     dmu_tx_t *tx, boolean_t recv, uint64_t cnt, cred_t *cr)
1185 {
1186         int error;
1187         uint64_t value;
1188
1189         ds->ds_trysnap_txg = tx->tx_txg;
1190
1191         if (!dmu_tx_is_syncing(tx))
1192                 return (0);
1193
1194         /*
1195          * We don't allow multiple snapshots of the same txg.  If there
1196          * is already one, try again.
1197          */
1198         if (dsl_dataset_phys(ds)->ds_prev_snap_txg >= tx->tx_txg)
1199                 return (SET_ERROR(EAGAIN));
1200
1201         /*
1202          * Check for conflicting snapshot name.
1203          */
1204         error = dsl_dataset_snap_lookup(ds, snapname, &value);
1205         if (error == 0)
1206                 return (SET_ERROR(EEXIST));
1207         if (error != ENOENT)
1208                 return (error);
1209
1210         /*
1211          * We don't allow taking snapshots of inconsistent datasets, such as
1212          * those into which we are currently receiving.  However, if we are
1213          * creating this snapshot as part of a receive, this check will be
1214          * executed atomically with respect to the completion of the receive
1215          * itself but prior to the clearing of DS_FLAG_INCONSISTENT; in this
1216          * case we ignore this, knowing it will be fixed up for us shortly in
1217          * dmu_recv_end_sync().
1218          */
1219         if (!recv && DS_IS_INCONSISTENT(ds))
1220                 return (SET_ERROR(EBUSY));
1221
1222         /*
1223          * Skip the check for temporary snapshots or if we have already checked
1224          * the counts in dsl_dataset_snapshot_check. This means we really only
1225          * check the count here when we're receiving a stream.
1226          */
1227         if (cnt != 0 && cr != NULL) {
1228                 error = dsl_fs_ss_limit_check(ds->ds_dir, cnt,
1229                     ZFS_PROP_SNAPSHOT_LIMIT, NULL, cr);
1230                 if (error != 0)
1231                         return (error);
1232         }
1233
1234         error = dsl_dataset_snapshot_reserve_space(ds, tx);
1235         if (error != 0)
1236                 return (error);
1237
1238         return (0);
1239 }
1240
1241 static int
1242 dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx)
1243 {
1244         dsl_dataset_snapshot_arg_t *ddsa = arg;
1245         dsl_pool_t *dp = dmu_tx_pool(tx);
1246         nvpair_t *pair;
1247         int rv = 0;
1248
1249         /*
1250          * Pre-compute how many total new snapshots will be created for each
1251          * level in the tree and below. This is needed for validating the
1252          * snapshot limit when either taking a recursive snapshot or when
1253          * taking multiple snapshots.
1254          *
1255          * The problem is that the counts are not actually adjusted when
1256          * we are checking, only when we finally sync. For a single snapshot,
1257          * this is easy, the count will increase by 1 at each node up the tree,
1258          * but its more complicated for the recursive/multiple snapshot case.
1259          *
1260          * The dsl_fs_ss_limit_check function does recursively check the count
1261          * at each level up the tree but since it is validating each snapshot
1262          * independently we need to be sure that we are validating the complete
1263          * count for the entire set of snapshots. We do this by rolling up the
1264          * counts for each component of the name into an nvlist and then
1265          * checking each of those cases with the aggregated count.
1266          *
1267          * This approach properly handles not only the recursive snapshot
1268          * case (where we get all of those on the ddsa_snaps list) but also
1269          * the sibling case (e.g. snapshot a/b and a/c so that we will also
1270          * validate the limit on 'a' using a count of 2).
1271          *
1272          * We validate the snapshot names in the third loop and only report
1273          * name errors once.
1274          */
1275         if (dmu_tx_is_syncing(tx)) {
1276                 nvlist_t *cnt_track = NULL;
1277                 cnt_track = fnvlist_alloc();
1278
1279                 /* Rollup aggregated counts into the cnt_track list */
1280                 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1281                     pair != NULL;
1282                     pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1283                         char *pdelim;
1284                         uint64_t val;
1285                         char nm[MAXPATHLEN];
1286
1287                         (void) strlcpy(nm, nvpair_name(pair), sizeof (nm));
1288                         pdelim = strchr(nm, '@');
1289                         if (pdelim == NULL)
1290                                 continue;
1291                         *pdelim = '\0';
1292
1293                         do {
1294                                 if (nvlist_lookup_uint64(cnt_track, nm,
1295                                     &val) == 0) {
1296                                         /* update existing entry */
1297                                         fnvlist_add_uint64(cnt_track, nm,
1298                                             val + 1);
1299                                 } else {
1300                                         /* add to list */
1301                                         fnvlist_add_uint64(cnt_track, nm, 1);
1302                                 }
1303
1304                                 pdelim = strrchr(nm, '/');
1305                                 if (pdelim != NULL)
1306                                         *pdelim = '\0';
1307                         } while (pdelim != NULL);
1308                 }
1309
1310                 /* Check aggregated counts at each level */
1311                 for (pair = nvlist_next_nvpair(cnt_track, NULL);
1312                     pair != NULL; pair = nvlist_next_nvpair(cnt_track, pair)) {
1313                         int error = 0;
1314                         char *name;
1315                         uint64_t cnt = 0;
1316                         dsl_dataset_t *ds;
1317
1318                         name = nvpair_name(pair);
1319                         cnt = fnvpair_value_uint64(pair);
1320                         ASSERT(cnt > 0);
1321
1322                         error = dsl_dataset_hold(dp, name, FTAG, &ds);
1323                         if (error == 0) {
1324                                 error = dsl_fs_ss_limit_check(ds->ds_dir, cnt,
1325                                     ZFS_PROP_SNAPSHOT_LIMIT, NULL,
1326                                     ddsa->ddsa_cr);
1327                                 dsl_dataset_rele(ds, FTAG);
1328                         }
1329
1330                         if (error != 0) {
1331                                 if (ddsa->ddsa_errors != NULL)
1332                                         fnvlist_add_int32(ddsa->ddsa_errors,
1333                                             name, error);
1334                                 rv = error;
1335                                 /* only report one error for this check */
1336                                 break;
1337                         }
1338                 }
1339                 nvlist_free(cnt_track);
1340         }
1341
1342         for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1343             pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1344                 int error = 0;
1345                 dsl_dataset_t *ds;
1346                 char *name, *atp;
1347                 char dsname[ZFS_MAX_DATASET_NAME_LEN];
1348
1349                 name = nvpair_name(pair);
1350                 if (strlen(name) >= ZFS_MAX_DATASET_NAME_LEN)
1351                         error = SET_ERROR(ENAMETOOLONG);
1352                 if (error == 0) {
1353                         atp = strchr(name, '@');
1354                         if (atp == NULL)
1355                                 error = SET_ERROR(EINVAL);
1356                         if (error == 0)
1357                                 (void) strlcpy(dsname, name, atp - name + 1);
1358                 }
1359                 if (error == 0)
1360                         error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
1361                 if (error == 0) {
1362                         /* passing 0/NULL skips dsl_fs_ss_limit_check */
1363                         error = dsl_dataset_snapshot_check_impl(ds,
1364                             atp + 1, tx, B_FALSE, 0, NULL);
1365                         dsl_dataset_rele(ds, FTAG);
1366                 }
1367
1368                 if (error != 0) {
1369                         if (ddsa->ddsa_errors != NULL) {
1370                                 fnvlist_add_int32(ddsa->ddsa_errors,
1371                                     name, error);
1372                         }
1373                         rv = error;
1374                 }
1375         }
1376
1377         return (rv);
1378 }
1379
1380 void
1381 dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
1382     dmu_tx_t *tx)
1383 {
1384         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1385         dmu_buf_t *dbuf;
1386         dsl_dataset_phys_t *dsphys;
1387         uint64_t dsobj, crtxg;
1388         objset_t *mos = dp->dp_meta_objset;
1389         objset_t *os;
1390
1391         ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
1392
1393         /*
1394          * If we are on an old pool, the zil must not be active, in which
1395          * case it will be zeroed.  Usually zil_suspend() accomplishes this.
1396          */
1397         ASSERT(spa_version(dmu_tx_pool(tx)->dp_spa) >= SPA_VERSION_FAST_SNAP ||
1398             dmu_objset_from_ds(ds, &os) != 0 ||
1399             bcmp(&os->os_phys->os_zil_header, &zero_zil,
1400             sizeof (zero_zil)) == 0);
1401
1402         /* Should not snapshot a dirty dataset. */
1403         ASSERT(!txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
1404             ds, tx->tx_txg));
1405
1406         dsl_fs_ss_count_adjust(ds->ds_dir, 1, DD_FIELD_SNAPSHOT_COUNT, tx);
1407
1408         /*
1409          * The origin's ds_creation_txg has to be < TXG_INITIAL
1410          */
1411         if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1412                 crtxg = 1;
1413         else
1414                 crtxg = tx->tx_txg;
1415
1416         dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1417             DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1418         VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1419         dmu_buf_will_dirty(dbuf, tx);
1420         dsphys = dbuf->db_data;
1421         bzero(dsphys, sizeof (dsl_dataset_phys_t));
1422         dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1423         dsphys->ds_fsid_guid = unique_create();
1424         do {
1425                 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1426                     sizeof (dsphys->ds_guid));
1427         } while (dsphys->ds_guid == 0);
1428         dsphys->ds_prev_snap_obj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
1429         dsphys->ds_prev_snap_txg = dsl_dataset_phys(ds)->ds_prev_snap_txg;
1430         dsphys->ds_next_snap_obj = ds->ds_object;
1431         dsphys->ds_num_children = 1;
1432         dsphys->ds_creation_time = gethrestime_sec();
1433         dsphys->ds_creation_txg = crtxg;
1434         dsphys->ds_deadlist_obj = dsl_dataset_phys(ds)->ds_deadlist_obj;
1435         dsphys->ds_referenced_bytes = dsl_dataset_phys(ds)->ds_referenced_bytes;
1436         dsphys->ds_compressed_bytes = dsl_dataset_phys(ds)->ds_compressed_bytes;
1437         dsphys->ds_uncompressed_bytes =
1438             dsl_dataset_phys(ds)->ds_uncompressed_bytes;
1439         dsphys->ds_flags = dsl_dataset_phys(ds)->ds_flags;
1440         rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
1441         dsphys->ds_bp = dsl_dataset_phys(ds)->ds_bp;
1442         rrw_exit(&ds->ds_bp_rwlock, FTAG);
1443         dmu_buf_rele(dbuf, FTAG);
1444
1445         for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
1446                 if (ds->ds_feature_inuse[f])
1447                         dsl_dataset_activate_feature(dsobj, f, tx);
1448         }
1449
1450         ASSERT3U(ds->ds_prev != 0, ==,
1451             dsl_dataset_phys(ds)->ds_prev_snap_obj != 0);
1452         if (ds->ds_prev) {
1453                 uint64_t next_clones_obj =
1454                     dsl_dataset_phys(ds->ds_prev)->ds_next_clones_obj;
1455                 ASSERT(dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj ==
1456                     ds->ds_object ||
1457                     dsl_dataset_phys(ds->ds_prev)->ds_num_children > 1);
1458                 if (dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj ==
1459                     ds->ds_object) {
1460                         dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1461                         ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==,
1462                             dsl_dataset_phys(ds->ds_prev)->ds_creation_txg);
1463                         dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj = dsobj;
1464                 } else if (next_clones_obj != 0) {
1465                         dsl_dataset_remove_from_next_clones(ds->ds_prev,
1466                             dsphys->ds_next_snap_obj, tx);
1467                         VERIFY0(zap_add_int(mos,
1468                             next_clones_obj, dsobj, tx));
1469                 }
1470         }
1471
1472         /*
1473          * If we have a reference-reservation on this dataset, we will
1474          * need to increase the amount of refreservation being charged
1475          * since our unique space is going to zero.
1476          */
1477         if (ds->ds_reserved) {
1478                 int64_t delta;
1479                 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
1480                 delta = MIN(dsl_dataset_phys(ds)->ds_unique_bytes,
1481                     ds->ds_reserved);
1482                 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1483                     delta, 0, 0, tx);
1484         }
1485
1486         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1487         dsl_dataset_phys(ds)->ds_deadlist_obj =
1488             dsl_deadlist_clone(&ds->ds_deadlist, UINT64_MAX,
1489             dsl_dataset_phys(ds)->ds_prev_snap_obj, tx);
1490         dsl_deadlist_close(&ds->ds_deadlist);
1491         dsl_deadlist_open(&ds->ds_deadlist, mos,
1492             dsl_dataset_phys(ds)->ds_deadlist_obj);
1493         dsl_deadlist_add_key(&ds->ds_deadlist,
1494             dsl_dataset_phys(ds)->ds_prev_snap_txg, tx);
1495
1496         ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, <, tx->tx_txg);
1497         dsl_dataset_phys(ds)->ds_prev_snap_obj = dsobj;
1498         dsl_dataset_phys(ds)->ds_prev_snap_txg = crtxg;
1499         dsl_dataset_phys(ds)->ds_unique_bytes = 0;
1500         if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1501                 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1502
1503         VERIFY0(zap_add(mos, dsl_dataset_phys(ds)->ds_snapnames_zapobj,
1504             snapname, 8, 1, &dsobj, tx));
1505
1506         if (ds->ds_prev)
1507                 dsl_dataset_rele(ds->ds_prev, ds);
1508         VERIFY0(dsl_dataset_hold_obj(dp,
1509             dsl_dataset_phys(ds)->ds_prev_snap_obj, ds, &ds->ds_prev));
1510
1511         dsl_scan_ds_snapshotted(ds, tx);
1512
1513         dsl_dir_snap_cmtime_update(ds->ds_dir);
1514
1515         spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
1516 }
1517
1518 static void
1519 dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx)
1520 {
1521         dsl_dataset_snapshot_arg_t *ddsa = arg;
1522         dsl_pool_t *dp = dmu_tx_pool(tx);
1523         nvpair_t *pair;
1524
1525         for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1526             pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1527                 dsl_dataset_t *ds;
1528                 char *name, *atp;
1529                 char dsname[ZFS_MAX_DATASET_NAME_LEN];
1530
1531                 name = nvpair_name(pair);
1532                 atp = strchr(name, '@');
1533                 (void) strlcpy(dsname, name, atp - name + 1);
1534                 VERIFY0(dsl_dataset_hold(dp, dsname, FTAG, &ds));
1535
1536                 dsl_dataset_snapshot_sync_impl(ds, atp + 1, tx);
1537                 if (ddsa->ddsa_props != NULL) {
1538                         dsl_props_set_sync_impl(ds->ds_prev,
1539                             ZPROP_SRC_LOCAL, ddsa->ddsa_props, tx);
1540                 }
1541                 dsl_dataset_rele(ds, FTAG);
1542         }
1543 }
1544
1545 /*
1546  * The snapshots must all be in the same pool.
1547  * All-or-nothing: if there are any failures, nothing will be modified.
1548  */
1549 int
1550 dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors)
1551 {
1552         dsl_dataset_snapshot_arg_t ddsa;
1553         nvpair_t *pair;
1554         boolean_t needsuspend;
1555         int error;
1556         spa_t *spa;
1557         char *firstname;
1558         nvlist_t *suspended = NULL;
1559
1560         pair = nvlist_next_nvpair(snaps, NULL);
1561         if (pair == NULL)
1562                 return (0);
1563         firstname = nvpair_name(pair);
1564
1565         error = spa_open(firstname, &spa, FTAG);
1566         if (error != 0)
1567                 return (error);
1568         needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1569         spa_close(spa, FTAG);
1570
1571         if (needsuspend) {
1572                 suspended = fnvlist_alloc();
1573                 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1574                     pair = nvlist_next_nvpair(snaps, pair)) {
1575                         char fsname[ZFS_MAX_DATASET_NAME_LEN];
1576                         char *snapname = nvpair_name(pair);
1577                         char *atp;
1578                         void *cookie;
1579
1580                         atp = strchr(snapname, '@');
1581                         if (atp == NULL) {
1582                                 error = SET_ERROR(EINVAL);
1583                                 break;
1584                         }
1585                         (void) strlcpy(fsname, snapname, atp - snapname + 1);
1586
1587                         error = zil_suspend(fsname, &cookie);
1588                         if (error != 0)
1589                                 break;
1590                         fnvlist_add_uint64(suspended, fsname,
1591                             (uintptr_t)cookie);
1592                 }
1593         }
1594
1595         ddsa.ddsa_snaps = snaps;
1596         ddsa.ddsa_props = props;
1597         ddsa.ddsa_errors = errors;
1598         ddsa.ddsa_cr = CRED();
1599
1600         if (error == 0) {
1601                 error = dsl_sync_task(firstname, dsl_dataset_snapshot_check,
1602                     dsl_dataset_snapshot_sync, &ddsa,
1603                     fnvlist_num_pairs(snaps) * 3, ZFS_SPACE_CHECK_NORMAL);
1604         }
1605
1606         if (suspended != NULL) {
1607                 for (pair = nvlist_next_nvpair(suspended, NULL); pair != NULL;
1608                     pair = nvlist_next_nvpair(suspended, pair)) {
1609                         zil_resume((void *)(uintptr_t)
1610                             fnvpair_value_uint64(pair));
1611                 }
1612                 fnvlist_free(suspended);
1613         }
1614
1615 #ifdef __FreeBSD__
1616 #ifdef _KERNEL
1617         if (error == 0) {
1618                 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1619                     pair = nvlist_next_nvpair(snaps, pair)) {
1620                         char *snapname = nvpair_name(pair);
1621                         zvol_create_minors(snapname);
1622                 }
1623         }
1624 #endif
1625 #endif
1626         return (error);
1627 }
1628
1629 typedef struct dsl_dataset_snapshot_tmp_arg {
1630         const char *ddsta_fsname;
1631         const char *ddsta_snapname;
1632         minor_t ddsta_cleanup_minor;
1633         const char *ddsta_htag;
1634 } dsl_dataset_snapshot_tmp_arg_t;
1635
1636 static int
1637 dsl_dataset_snapshot_tmp_check(void *arg, dmu_tx_t *tx)
1638 {
1639         dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1640         dsl_pool_t *dp = dmu_tx_pool(tx);
1641         dsl_dataset_t *ds;
1642         int error;
1643
1644         error = dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds);
1645         if (error != 0)
1646                 return (error);
1647
1648         /* NULL cred means no limit check for tmp snapshot */
1649         error = dsl_dataset_snapshot_check_impl(ds, ddsta->ddsta_snapname,
1650             tx, B_FALSE, 0, NULL);
1651         if (error != 0) {
1652                 dsl_dataset_rele(ds, FTAG);
1653                 return (error);
1654         }
1655
1656         if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS) {
1657                 dsl_dataset_rele(ds, FTAG);
1658                 return (SET_ERROR(ENOTSUP));
1659         }
1660         error = dsl_dataset_user_hold_check_one(NULL, ddsta->ddsta_htag,
1661             B_TRUE, tx);
1662         if (error != 0) {
1663                 dsl_dataset_rele(ds, FTAG);
1664                 return (error);
1665         }
1666
1667         dsl_dataset_rele(ds, FTAG);
1668         return (0);
1669 }
1670
1671 static void
1672 dsl_dataset_snapshot_tmp_sync(void *arg, dmu_tx_t *tx)
1673 {
1674         dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1675         dsl_pool_t *dp = dmu_tx_pool(tx);
1676         dsl_dataset_t *ds;
1677
1678         VERIFY0(dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds));
1679
1680         dsl_dataset_snapshot_sync_impl(ds, ddsta->ddsta_snapname, tx);
1681         dsl_dataset_user_hold_sync_one(ds->ds_prev, ddsta->ddsta_htag,
1682             ddsta->ddsta_cleanup_minor, gethrestime_sec(), tx);
1683         dsl_destroy_snapshot_sync_impl(ds->ds_prev, B_TRUE, tx);
1684
1685         dsl_dataset_rele(ds, FTAG);
1686 }
1687
1688 int
1689 dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
1690     minor_t cleanup_minor, const char *htag)
1691 {
1692         dsl_dataset_snapshot_tmp_arg_t ddsta;
1693         int error;
1694         spa_t *spa;
1695         boolean_t needsuspend;
1696         void *cookie;
1697
1698         ddsta.ddsta_fsname = fsname;
1699         ddsta.ddsta_snapname = snapname;
1700         ddsta.ddsta_cleanup_minor = cleanup_minor;
1701         ddsta.ddsta_htag = htag;
1702
1703         error = spa_open(fsname, &spa, FTAG);
1704         if (error != 0)
1705                 return (error);
1706         needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1707         spa_close(spa, FTAG);
1708
1709         if (needsuspend) {
1710                 error = zil_suspend(fsname, &cookie);
1711                 if (error != 0)
1712                         return (error);
1713         }
1714
1715         error = dsl_sync_task(fsname, dsl_dataset_snapshot_tmp_check,
1716             dsl_dataset_snapshot_tmp_sync, &ddsta, 3, ZFS_SPACE_CHECK_RESERVED);
1717
1718         if (needsuspend)
1719                 zil_resume(cookie);
1720         return (error);
1721 }
1722
1723
1724 void
1725 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1726 {
1727         ASSERT(dmu_tx_is_syncing(tx));
1728         ASSERT(ds->ds_objset != NULL);
1729         ASSERT(dsl_dataset_phys(ds)->ds_next_snap_obj == 0);
1730
1731         /*
1732          * in case we had to change ds_fsid_guid when we opened it,
1733          * sync it out now.
1734          */
1735         dmu_buf_will_dirty(ds->ds_dbuf, tx);
1736         dsl_dataset_phys(ds)->ds_fsid_guid = ds->ds_fsid_guid;
1737
1738         if (ds->ds_resume_bytes[tx->tx_txg & TXG_MASK] != 0) {
1739                 VERIFY0(zap_update(tx->tx_pool->dp_meta_objset,
1740                     ds->ds_object, DS_FIELD_RESUME_OBJECT, 8, 1,
1741                     &ds->ds_resume_object[tx->tx_txg & TXG_MASK], tx));
1742                 VERIFY0(zap_update(tx->tx_pool->dp_meta_objset,
1743                     ds->ds_object, DS_FIELD_RESUME_OFFSET, 8, 1,
1744                     &ds->ds_resume_offset[tx->tx_txg & TXG_MASK], tx));
1745                 VERIFY0(zap_update(tx->tx_pool->dp_meta_objset,
1746                     ds->ds_object, DS_FIELD_RESUME_BYTES, 8, 1,
1747                     &ds->ds_resume_bytes[tx->tx_txg & TXG_MASK], tx));
1748                 ds->ds_resume_object[tx->tx_txg & TXG_MASK] = 0;
1749                 ds->ds_resume_offset[tx->tx_txg & TXG_MASK] = 0;
1750                 ds->ds_resume_bytes[tx->tx_txg & TXG_MASK] = 0;
1751         }
1752
1753         dmu_objset_sync(ds->ds_objset, zio, tx);
1754
1755         for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
1756                 if (ds->ds_feature_activation_needed[f]) {
1757                         if (ds->ds_feature_inuse[f])
1758                                 continue;
1759                         dsl_dataset_activate_feature(ds->ds_object, f, tx);
1760                         ds->ds_feature_inuse[f] = B_TRUE;
1761                 }
1762         }
1763 }
1764
1765 static int
1766 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1767 {
1768         dsl_deadlist_t *dl = arg;
1769         dsl_deadlist_insert(dl, bp, tx);
1770         return (0);
1771 }
1772
1773 void
1774 dsl_dataset_sync_done(dsl_dataset_t *ds, dmu_tx_t *tx)
1775 {
1776         objset_t *os = ds->ds_objset;
1777
1778         bplist_iterate(&ds->ds_pending_deadlist,
1779             deadlist_enqueue_cb, &ds->ds_deadlist, tx);
1780
1781         ASSERT(!dmu_objset_is_dirty(os, dmu_tx_get_txg(tx)));
1782
1783         dmu_buf_rele(ds->ds_dbuf, ds);
1784 }
1785
1786 static void
1787 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
1788 {
1789         uint64_t count = 0;
1790         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1791         zap_cursor_t zc;
1792         zap_attribute_t za;
1793         nvlist_t *propval = fnvlist_alloc();
1794         nvlist_t *val = fnvlist_alloc();
1795
1796         ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1797
1798         /*
1799          * There may be missing entries in ds_next_clones_obj
1800          * due to a bug in a previous version of the code.
1801          * Only trust it if it has the right number of entries.
1802          */
1803         if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) {
1804                 VERIFY0(zap_count(mos, dsl_dataset_phys(ds)->ds_next_clones_obj,
1805                     &count));
1806         }
1807         if (count != dsl_dataset_phys(ds)->ds_num_children - 1)
1808                 goto fail;
1809         for (zap_cursor_init(&zc, mos,
1810             dsl_dataset_phys(ds)->ds_next_clones_obj);
1811             zap_cursor_retrieve(&zc, &za) == 0;
1812             zap_cursor_advance(&zc)) {
1813                 dsl_dataset_t *clone;
1814                 char buf[ZFS_MAX_DATASET_NAME_LEN];
1815                 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1816                     za.za_first_integer, FTAG, &clone));
1817                 dsl_dir_name(clone->ds_dir, buf);
1818                 fnvlist_add_boolean(val, buf);
1819                 dsl_dataset_rele(clone, FTAG);
1820         }
1821         zap_cursor_fini(&zc);
1822         fnvlist_add_nvlist(propval, ZPROP_VALUE, val);
1823         fnvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval);
1824 fail:
1825         nvlist_free(val);
1826         nvlist_free(propval);
1827 }
1828
1829 static void
1830 get_receive_resume_stats(dsl_dataset_t *ds, nvlist_t *nv)
1831 {
1832         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1833
1834         if (dsl_dataset_has_resume_receive_state(ds)) {
1835                 char *str;
1836                 void *packed;
1837                 uint8_t *compressed;
1838                 uint64_t val;
1839                 nvlist_t *token_nv = fnvlist_alloc();
1840                 size_t packed_size, compressed_size;
1841
1842                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1843                     DS_FIELD_RESUME_FROMGUID, sizeof (val), 1, &val) == 0) {
1844                         fnvlist_add_uint64(token_nv, "fromguid", val);
1845                 }
1846                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1847                     DS_FIELD_RESUME_OBJECT, sizeof (val), 1, &val) == 0) {
1848                         fnvlist_add_uint64(token_nv, "object", val);
1849                 }
1850                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1851                     DS_FIELD_RESUME_OFFSET, sizeof (val), 1, &val) == 0) {
1852                         fnvlist_add_uint64(token_nv, "offset", val);
1853                 }
1854                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1855                     DS_FIELD_RESUME_BYTES, sizeof (val), 1, &val) == 0) {
1856                         fnvlist_add_uint64(token_nv, "bytes", val);
1857                 }
1858                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1859                     DS_FIELD_RESUME_TOGUID, sizeof (val), 1, &val) == 0) {
1860                         fnvlist_add_uint64(token_nv, "toguid", val);
1861                 }
1862                 char buf[256];
1863                 if (zap_lookup(dp->dp_meta_objset, ds->ds_object,
1864                     DS_FIELD_RESUME_TONAME, 1, sizeof (buf), buf) == 0) {
1865                         fnvlist_add_string(token_nv, "toname", buf);
1866                 }
1867                 if (zap_contains(dp->dp_meta_objset, ds->ds_object,
1868                     DS_FIELD_RESUME_EMBEDOK) == 0) {
1869                         fnvlist_add_boolean(token_nv, "embedok");
1870                 }
1871                 packed = fnvlist_pack(token_nv, &packed_size);
1872                 fnvlist_free(token_nv);
1873                 compressed = kmem_alloc(packed_size, KM_SLEEP);
1874
1875                 compressed_size = gzip_compress(packed, compressed,
1876                     packed_size, packed_size, 6);
1877
1878                 zio_cksum_t cksum;
1879                 fletcher_4_native(compressed, compressed_size, NULL, &cksum);
1880
1881                 str = kmem_alloc(compressed_size * 2 + 1, KM_SLEEP);
1882                 for (int i = 0; i < compressed_size; i++) {
1883                         (void) sprintf(str + i * 2, "%02x", compressed[i]);
1884                 }
1885                 str[compressed_size * 2] = '\0';
1886                 char *propval = kmem_asprintf("%u-%llx-%llx-%s",
1887                     ZFS_SEND_RESUME_TOKEN_VERSION,
1888                     (longlong_t)cksum.zc_word[0],
1889                     (longlong_t)packed_size, str);
1890                 dsl_prop_nvlist_add_string(nv,
1891                     ZFS_PROP_RECEIVE_RESUME_TOKEN, propval);
1892                 kmem_free(packed, packed_size);
1893                 kmem_free(str, compressed_size * 2 + 1);
1894                 kmem_free(compressed, packed_size);
1895                 strfree(propval);
1896         }
1897 }
1898
1899 void
1900 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1901 {
1902         dsl_pool_t *dp = ds->ds_dir->dd_pool;
1903         uint64_t refd, avail, uobjs, aobjs, ratio;
1904
1905         ASSERT(dsl_pool_config_held(dp));
1906
1907         ratio = dsl_dataset_phys(ds)->ds_compressed_bytes == 0 ? 100 :
1908             (dsl_dataset_phys(ds)->ds_uncompressed_bytes * 100 /
1909             dsl_dataset_phys(ds)->ds_compressed_bytes);
1910
1911         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
1912         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
1913             dsl_dataset_phys(ds)->ds_uncompressed_bytes);
1914
1915         if (ds->ds_is_snapshot) {
1916                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
1917                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1918                     dsl_dataset_phys(ds)->ds_unique_bytes);
1919                 get_clones_stat(ds, nv);
1920         } else {
1921                 if (ds->ds_prev != NULL && ds->ds_prev != dp->dp_origin_snap) {
1922                         char buf[ZFS_MAX_DATASET_NAME_LEN];
1923                         dsl_dataset_name(ds->ds_prev, buf);
1924                         dsl_prop_nvlist_add_string(nv, ZFS_PROP_PREV_SNAP, buf);
1925                 }
1926
1927                 dsl_dir_stats(ds->ds_dir, nv);
1928         }
1929
1930         dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1931         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1932         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1933
1934         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1935             dsl_dataset_phys(ds)->ds_creation_time);
1936         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1937             dsl_dataset_phys(ds)->ds_creation_txg);
1938         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1939             ds->ds_quota);
1940         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1941             ds->ds_reserved);
1942         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1943             dsl_dataset_phys(ds)->ds_guid);
1944         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
1945             dsl_dataset_phys(ds)->ds_unique_bytes);
1946         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
1947             ds->ds_object);
1948         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
1949             ds->ds_userrefs);
1950         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
1951             DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
1952
1953         if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
1954                 uint64_t written, comp, uncomp;
1955                 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1956                 dsl_dataset_t *prev;
1957
1958                 int err = dsl_dataset_hold_obj(dp,
1959                     dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &prev);
1960                 if (err == 0) {
1961                         err = dsl_dataset_space_written(prev, ds, &written,
1962                             &comp, &uncomp);
1963                         dsl_dataset_rele(prev, FTAG);
1964                         if (err == 0) {
1965                                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
1966                                     written);
1967                         }
1968                 }
1969         }
1970
1971         if (!dsl_dataset_is_snapshot(ds)) {
1972                 /*
1973                  * A failed "newfs" (e.g. full) resumable receive leaves
1974                  * the stats set on this dataset.  Check here for the prop.
1975                  */
1976                 get_receive_resume_stats(ds, nv);
1977
1978                 /*
1979                  * A failed incremental resumable receive leaves the
1980                  * stats set on our child named "%recv".  Check the child
1981                  * for the prop.
1982                  */
1983                 /* 6 extra bytes for /%recv */
1984                 char recvname[ZFS_MAX_DATASET_NAME_LEN + 6];
1985                 dsl_dataset_t *recv_ds;
1986                 dsl_dataset_name(ds, recvname);
1987                 if (strlcat(recvname, "/", sizeof (recvname)) <
1988                     sizeof (recvname) &&
1989                     strlcat(recvname, recv_clone_name, sizeof (recvname)) <
1990                     sizeof (recvname) &&
1991                     dsl_dataset_hold(dp, recvname, FTAG, &recv_ds) == 0) {
1992                         get_receive_resume_stats(recv_ds, nv);
1993                         dsl_dataset_rele(recv_ds, FTAG);
1994                 }
1995         }
1996 }
1997
1998 void
1999 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2000 {
2001         dsl_pool_t *dp = ds->ds_dir->dd_pool;
2002         ASSERT(dsl_pool_config_held(dp));
2003
2004         stat->dds_creation_txg = dsl_dataset_phys(ds)->ds_creation_txg;
2005         stat->dds_inconsistent =
2006             dsl_dataset_phys(ds)->ds_flags & DS_FLAG_INCONSISTENT;
2007         stat->dds_guid = dsl_dataset_phys(ds)->ds_guid;
2008         stat->dds_origin[0] = '\0';
2009         if (ds->ds_is_snapshot) {
2010                 stat->dds_is_snapshot = B_TRUE;
2011                 stat->dds_num_clones =
2012                     dsl_dataset_phys(ds)->ds_num_children - 1;
2013         } else {
2014                 stat->dds_is_snapshot = B_FALSE;
2015                 stat->dds_num_clones = 0;
2016
2017                 if (dsl_dir_is_clone(ds->ds_dir)) {
2018                         dsl_dataset_t *ods;
2019
2020                         VERIFY0(dsl_dataset_hold_obj(dp,
2021                             dsl_dir_phys(ds->ds_dir)->dd_origin_obj,
2022                             FTAG, &ods));
2023                         dsl_dataset_name(ods, stat->dds_origin);
2024                         dsl_dataset_rele(ods, FTAG);
2025                 }
2026         }
2027 }
2028
2029 uint64_t
2030 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2031 {
2032         return (ds->ds_fsid_guid);
2033 }
2034
2035 void
2036 dsl_dataset_space(dsl_dataset_t *ds,
2037     uint64_t *refdbytesp, uint64_t *availbytesp,
2038     uint64_t *usedobjsp, uint64_t *availobjsp)
2039 {
2040         *refdbytesp = dsl_dataset_phys(ds)->ds_referenced_bytes;
2041         *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2042         if (ds->ds_reserved > dsl_dataset_phys(ds)->ds_unique_bytes)
2043                 *availbytesp +=
2044                     ds->ds_reserved - dsl_dataset_phys(ds)->ds_unique_bytes;
2045         if (ds->ds_quota != 0) {
2046                 /*
2047                  * Adjust available bytes according to refquota
2048                  */
2049                 if (*refdbytesp < ds->ds_quota)
2050                         *availbytesp = MIN(*availbytesp,
2051                             ds->ds_quota - *refdbytesp);
2052                 else
2053                         *availbytesp = 0;
2054         }
2055         rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
2056         *usedobjsp = BP_GET_FILL(&dsl_dataset_phys(ds)->ds_bp);
2057         rrw_exit(&ds->ds_bp_rwlock, FTAG);
2058         *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2059 }
2060
2061 boolean_t
2062 dsl_dataset_modified_since_snap(dsl_dataset_t *ds, dsl_dataset_t *snap)
2063 {
2064         dsl_pool_t *dp = ds->ds_dir->dd_pool;
2065         uint64_t birth;
2066
2067         ASSERT(dsl_pool_config_held(dp));
2068         if (snap == NULL)
2069                 return (B_FALSE);
2070         rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
2071         birth = dsl_dataset_get_blkptr(ds)->blk_birth;
2072         rrw_exit(&ds->ds_bp_rwlock, FTAG);
2073         if (birth > dsl_dataset_phys(snap)->ds_creation_txg) {
2074                 objset_t *os, *os_snap;
2075                 /*
2076                  * It may be that only the ZIL differs, because it was
2077                  * reset in the head.  Don't count that as being
2078                  * modified.
2079                  */
2080                 if (dmu_objset_from_ds(ds, &os) != 0)
2081                         return (B_TRUE);
2082                 if (dmu_objset_from_ds(snap, &os_snap) != 0)
2083                         return (B_TRUE);
2084                 return (bcmp(&os->os_phys->os_meta_dnode,
2085                     &os_snap->os_phys->os_meta_dnode,
2086                     sizeof (os->os_phys->os_meta_dnode)) != 0);
2087         }
2088         return (B_FALSE);
2089 }
2090
2091 typedef struct dsl_dataset_rename_snapshot_arg {
2092         const char *ddrsa_fsname;
2093         const char *ddrsa_oldsnapname;
2094         const char *ddrsa_newsnapname;
2095         boolean_t ddrsa_recursive;
2096         dmu_tx_t *ddrsa_tx;
2097 } dsl_dataset_rename_snapshot_arg_t;
2098
2099 /* ARGSUSED */
2100 static int
2101 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
2102     dsl_dataset_t *hds, void *arg)
2103 {
2104         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
2105         int error;
2106         uint64_t val;
2107
2108         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
2109         if (error != 0) {
2110                 /* ignore nonexistent snapshots */
2111                 return (error == ENOENT ? 0 : error);
2112         }
2113
2114         /* new name should not exist */
2115         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_newsnapname, &val);
2116         if (error == 0)
2117                 error = SET_ERROR(EEXIST);
2118         else if (error == ENOENT)
2119                 error = 0;
2120
2121         /* dataset name + 1 for the "@" + the new snapshot name must fit */
2122         if (dsl_dir_namelen(hds->ds_dir) + 1 +
2123             strlen(ddrsa->ddrsa_newsnapname) >= ZFS_MAX_DATASET_NAME_LEN)
2124                 error = SET_ERROR(ENAMETOOLONG);
2125
2126         return (error);
2127 }
2128
2129 static int
2130 dsl_dataset_rename_snapshot_check(void *arg, dmu_tx_t *tx)
2131 {
2132         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
2133         dsl_pool_t *dp = dmu_tx_pool(tx);
2134         dsl_dataset_t *hds;
2135         int error;
2136
2137         error = dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds);
2138         if (error != 0)
2139                 return (error);
2140
2141         if (ddrsa->ddrsa_recursive) {
2142                 error = dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
2143                     dsl_dataset_rename_snapshot_check_impl, ddrsa,
2144                     DS_FIND_CHILDREN);
2145         } else {
2146                 error = dsl_dataset_rename_snapshot_check_impl(dp, hds, ddrsa);
2147         }
2148         dsl_dataset_rele(hds, FTAG);
2149         return (error);
2150 }
2151
2152 static int
2153 dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
2154     dsl_dataset_t *hds, void *arg)
2155 {
2156 #ifdef __FreeBSD__
2157 #ifdef _KERNEL
2158         char *oldname, *newname;
2159 #endif
2160 #endif
2161         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
2162         dsl_dataset_t *ds;
2163         uint64_t val;
2164         dmu_tx_t *tx = ddrsa->ddrsa_tx;
2165         int error;
2166
2167         error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
2168         ASSERT(error == 0 || error == ENOENT);
2169         if (error == ENOENT) {
2170                 /* ignore nonexistent snapshots */
2171                 return (0);
2172         }
2173
2174         VERIFY0(dsl_dataset_hold_obj(dp, val, FTAG, &ds));
2175
2176         /* log before we change the name */
2177         spa_history_log_internal_ds(ds, "rename", tx,
2178             "-> @%s", ddrsa->ddrsa_newsnapname);
2179
2180         VERIFY0(dsl_dataset_snap_remove(hds, ddrsa->ddrsa_oldsnapname, tx,
2181             B_FALSE));
2182         mutex_enter(&ds->ds_lock);
2183         (void) strcpy(ds->ds_snapname, ddrsa->ddrsa_newsnapname);
2184         mutex_exit(&ds->ds_lock);
2185         VERIFY0(zap_add(dp->dp_meta_objset,
2186             dsl_dataset_phys(hds)->ds_snapnames_zapobj,
2187             ds->ds_snapname, 8, 1, &ds->ds_object, tx));
2188
2189 #ifdef __FreeBSD__
2190 #ifdef _KERNEL
2191         oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2192         newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2193         snprintf(oldname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
2194             ddrsa->ddrsa_oldsnapname);
2195         snprintf(newname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
2196             ddrsa->ddrsa_newsnapname);
2197         zfsvfs_update_fromname(oldname, newname);
2198         zvol_rename_minors(oldname, newname);
2199         kmem_free(newname, MAXPATHLEN);
2200         kmem_free(oldname, MAXPATHLEN);
2201 #endif
2202 #endif
2203         dsl_dataset_rele(ds, FTAG);
2204
2205         return (0);
2206 }
2207
2208 static void
2209 dsl_dataset_rename_snapshot_sync(void *arg, dmu_tx_t *tx)
2210 {
2211         dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
2212         dsl_pool_t *dp = dmu_tx_pool(tx);
2213         dsl_dataset_t *hds;
2214
2215         VERIFY0(dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds));
2216         ddrsa->ddrsa_tx = tx;
2217         if (ddrsa->ddrsa_recursive) {
2218                 VERIFY0(dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
2219                     dsl_dataset_rename_snapshot_sync_impl, ddrsa,
2220                     DS_FIND_CHILDREN));
2221         } else {
2222                 VERIFY0(dsl_dataset_rename_snapshot_sync_impl(dp, hds, ddrsa));
2223         }
2224         dsl_dataset_rele(hds, FTAG);
2225 }
2226
2227 int
2228 dsl_dataset_rename_snapshot(const char *fsname,
2229     const char *oldsnapname, const char *newsnapname, boolean_t recursive)
2230 {
2231         dsl_dataset_rename_snapshot_arg_t ddrsa;
2232
2233         ddrsa.ddrsa_fsname = fsname;
2234         ddrsa.ddrsa_oldsnapname = oldsnapname;
2235         ddrsa.ddrsa_newsnapname = newsnapname;
2236         ddrsa.ddrsa_recursive = recursive;
2237
2238         return (dsl_sync_task(fsname, dsl_dataset_rename_snapshot_check,
2239             dsl_dataset_rename_snapshot_sync, &ddrsa,
2240             1, ZFS_SPACE_CHECK_RESERVED));
2241 }
2242
2243 /*
2244  * If we're doing an ownership handoff, we need to make sure that there is
2245  * only one long hold on the dataset.  We're not allowed to change anything here
2246  * so we don't permanently release the long hold or regular hold here.  We want
2247  * to do this only when syncing to avoid the dataset unexpectedly going away
2248  * when we release the long hold.
2249  */
2250 static int
2251 dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx)
2252 {
2253         boolean_t held;
2254
2255         if (!dmu_tx_is_syncing(tx))
2256                 return (0);
2257
2258         if (owner != NULL) {
2259                 VERIFY3P(ds->ds_owner, ==, owner);
2260                 dsl_dataset_long_rele(ds, owner);
2261         }
2262
2263         held = dsl_dataset_long_held(ds);
2264
2265         if (owner != NULL)
2266                 dsl_dataset_long_hold(ds, owner);
2267
2268         if (held)
2269                 return (SET_ERROR(EBUSY));
2270
2271         return (0);
2272 }
2273
2274 typedef struct dsl_dataset_rollback_arg {
2275         const char *ddra_fsname;
2276         void *ddra_owner;
2277         nvlist_t *ddra_result;
2278 } dsl_dataset_rollback_arg_t;
2279
2280 static int
2281 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
2282 {
2283         dsl_dataset_rollback_arg_t *ddra = arg;
2284         dsl_pool_t *dp = dmu_tx_pool(tx);
2285         dsl_dataset_t *ds;
2286         int64_t unused_refres_delta;
2287         int error;
2288
2289         error = dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds);
2290         if (error != 0)
2291                 return (error);
2292
2293         /* must not be a snapshot */
2294         if (ds->ds_is_snapshot) {
2295                 dsl_dataset_rele(ds, FTAG);
2296                 return (SET_ERROR(EINVAL));
2297         }
2298
2299         /* must have a most recent snapshot */
2300         if (dsl_dataset_phys(ds)->ds_prev_snap_txg < TXG_INITIAL) {
2301                 dsl_dataset_rele(ds, FTAG);
2302                 return (SET_ERROR(EINVAL));
2303         }
2304
2305         /*
2306          * No rollback to a snapshot created in the current txg, because
2307          * the rollback may dirty the dataset and create blocks that are
2308          * not reachable from the rootbp while having a birth txg that
2309          * falls into the snapshot's range.
2310          */
2311         if (dmu_tx_is_syncing(tx) &&
2312             dsl_dataset_phys(ds)->ds_prev_snap_txg >= tx->tx_txg) {
2313                 dsl_dataset_rele(ds, FTAG);
2314                 return (SET_ERROR(EAGAIN));
2315         }
2316
2317         /* must not have any bookmarks after the most recent snapshot */
2318         nvlist_t *proprequest = fnvlist_alloc();
2319         fnvlist_add_boolean(proprequest, zfs_prop_to_name(ZFS_PROP_CREATETXG));
2320         nvlist_t *bookmarks = fnvlist_alloc();
2321         error = dsl_get_bookmarks_impl(ds, proprequest, bookmarks);
2322         fnvlist_free(proprequest);
2323         if (error != 0)
2324                 return (error);
2325         for (nvpair_t *pair = nvlist_next_nvpair(bookmarks, NULL);
2326             pair != NULL; pair = nvlist_next_nvpair(bookmarks, pair)) {
2327                 nvlist_t *valuenv =
2328                     fnvlist_lookup_nvlist(fnvpair_value_nvlist(pair),
2329                     zfs_prop_to_name(ZFS_PROP_CREATETXG));
2330                 uint64_t createtxg = fnvlist_lookup_uint64(valuenv, "value");
2331                 if (createtxg > dsl_dataset_phys(ds)->ds_prev_snap_txg) {
2332                         fnvlist_free(bookmarks);
2333                         dsl_dataset_rele(ds, FTAG);
2334                         return (SET_ERROR(EEXIST));
2335                 }
2336         }
2337         fnvlist_free(bookmarks);
2338
2339         error = dsl_dataset_handoff_check(ds, ddra->ddra_owner, tx);
2340         if (error != 0) {
2341                 dsl_dataset_rele(ds, FTAG);
2342                 return (error);
2343         }
2344
2345         /*
2346          * Check if the snap we are rolling back to uses more than
2347          * the refquota.
2348          */
2349         if (ds->ds_quota != 0 &&
2350             dsl_dataset_phys(ds->ds_prev)->ds_referenced_bytes > ds->ds_quota) {
2351                 dsl_dataset_rele(ds, FTAG);
2352                 return (SET_ERROR(EDQUOT));
2353         }
2354
2355         /*
2356          * When we do the clone swap, we will temporarily use more space
2357          * due to the refreservation (the head will no longer have any
2358          * unique space, so the entire amount of the refreservation will need
2359          * to be free).  We will immediately destroy the clone, freeing
2360          * this space, but the freeing happens over many txg's.
2361          */
2362         unused_refres_delta = (int64_t)MIN(ds->ds_reserved,
2363             dsl_dataset_phys(ds)->ds_unique_bytes);
2364
2365         if (unused_refres_delta > 0 &&
2366             unused_refres_delta >
2367             dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) {
2368                 dsl_dataset_rele(ds, FTAG);
2369                 return (SET_ERROR(ENOSPC));
2370         }
2371
2372         dsl_dataset_rele(ds, FTAG);
2373         return (0);
2374 }
2375
2376 static void
2377 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
2378 {
2379         dsl_dataset_rollback_arg_t *ddra = arg;
2380         dsl_pool_t *dp = dmu_tx_pool(tx);
2381         dsl_dataset_t *ds, *clone;
2382         uint64_t cloneobj;
2383         char namebuf[ZFS_MAX_DATASET_NAME_LEN];
2384
2385         VERIFY0(dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds));
2386
2387         dsl_dataset_name(ds->ds_prev, namebuf);
2388         fnvlist_add_string(ddra->ddra_result, "target", namebuf);
2389
2390         cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback",
2391             ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx);
2392
2393         VERIFY0(dsl_dataset_hold_obj(dp, cloneobj, FTAG, &clone));
2394
2395         dsl_dataset_clone_swap_sync_impl(clone, ds, tx);
2396         dsl_dataset_zero_zil(ds, tx);
2397
2398         dsl_destroy_head_sync_impl(clone, tx);
2399
2400         dsl_dataset_rele(clone, FTAG);
2401         dsl_dataset_rele(ds, FTAG);
2402 }
2403
2404 /*
2405  * Rolls back the given filesystem or volume to the most recent snapshot.
2406  * The name of the most recent snapshot will be returned under key "target"
2407  * in the result nvlist.
2408  *
2409  * If owner != NULL:
2410  * - The existing dataset MUST be owned by the specified owner at entry
2411  * - Upon return, dataset will still be held by the same owner, whether we
2412  *   succeed or not.
2413  *
2414  * This mode is required any time the existing filesystem is mounted.  See
2415  * notes above zfs_suspend_fs() for further details.
2416  */
2417 int
2418 dsl_dataset_rollback(const char *fsname, void *owner, nvlist_t *result)
2419 {
2420         dsl_dataset_rollback_arg_t ddra;
2421
2422         ddra.ddra_fsname = fsname;
2423         ddra.ddra_owner = owner;
2424         ddra.ddra_result = result;
2425
2426         return (dsl_sync_task(fsname, dsl_dataset_rollback_check,
2427             dsl_dataset_rollback_sync, &ddra,
2428             1, ZFS_SPACE_CHECK_RESERVED));
2429 }
2430
2431 struct promotenode {
2432         list_node_t link;
2433         dsl_dataset_t *ds;
2434 };
2435
2436 typedef struct dsl_dataset_promote_arg {
2437         const char *ddpa_clonename;
2438         dsl_dataset_t *ddpa_clone;
2439         list_t shared_snaps, origin_snaps, clone_snaps;
2440         dsl_dataset_t *origin_origin; /* origin of the origin */
2441         uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2442         char *err_ds;
2443         cred_t *cr;
2444 } dsl_dataset_promote_arg_t;
2445
2446 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2447 static int promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp,
2448     void *tag);
2449 static void promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag);
2450
2451 static int
2452 dsl_dataset_promote_check(void *arg, dmu_tx_t *tx)
2453 {
2454         dsl_dataset_promote_arg_t *ddpa = arg;
2455         dsl_pool_t *dp = dmu_tx_pool(tx);
2456         dsl_dataset_t *hds;
2457         struct promotenode *snap;
2458         dsl_dataset_t *origin_ds;
2459         int err;
2460         uint64_t unused;
2461         uint64_t ss_mv_cnt;
2462         size_t max_snap_len;
2463
2464         err = promote_hold(ddpa, dp, FTAG);
2465         if (err != 0)
2466                 return (err);
2467
2468         hds = ddpa->ddpa_clone;
2469         max_snap_len = MAXNAMELEN - strlen(ddpa->ddpa_clonename) - 1;
2470
2471         if (dsl_dataset_phys(hds)->ds_flags & DS_FLAG_NOPROMOTE) {
2472                 promote_rele(ddpa, FTAG);
2473                 return (SET_ERROR(EXDEV));
2474         }
2475
2476         /*
2477          * Compute and check the amount of space to transfer.  Since this is
2478          * so expensive, don't do the preliminary check.
2479          */
2480         if (!dmu_tx_is_syncing(tx)) {
2481                 promote_rele(ddpa, FTAG);
2482                 return (0);
2483         }
2484
2485         snap = list_head(&ddpa->shared_snaps);
2486         origin_ds = snap->ds;
2487
2488         /* compute origin's new unique space */
2489         snap = list_tail(&ddpa->clone_snaps);
2490         ASSERT3U(dsl_dataset_phys(snap->ds)->ds_prev_snap_obj, ==,
2491             origin_ds->ds_object);
2492         dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2493             dsl_dataset_phys(origin_ds)->ds_prev_snap_txg, UINT64_MAX,
2494             &ddpa->unique, &unused, &unused);
2495
2496         /*
2497          * Walk the snapshots that we are moving
2498          *
2499          * Compute space to transfer.  Consider the incremental changes
2500          * to used by each snapshot:
2501          * (my used) = (prev's used) + (blocks born) - (blocks killed)
2502          * So each snapshot gave birth to:
2503          * (blocks born) = (my used) - (prev's used) + (blocks killed)
2504          * So a sequence would look like:
2505          * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2506          * Which simplifies to:
2507          * uN + kN + kN-1 + ... + k1 + k0
2508          * Note however, if we stop before we reach the ORIGIN we get:
2509          * uN + kN + kN-1 + ... + kM - uM-1
2510          */
2511         ss_mv_cnt = 0;
2512         ddpa->used = dsl_dataset_phys(origin_ds)->ds_referenced_bytes;
2513         ddpa->comp = dsl_dataset_phys(origin_ds)->ds_compressed_bytes;
2514         ddpa->uncomp = dsl_dataset_phys(origin_ds)->ds_uncompressed_bytes;
2515         for (snap = list_head(&ddpa->shared_snaps); snap;
2516             snap = list_next(&ddpa->shared_snaps, snap)) {
2517                 uint64_t val, dlused, dlcomp, dluncomp;
2518                 dsl_dataset_t *ds = snap->ds;
2519
2520                 ss_mv_cnt++;
2521
2522                 /*
2523                  * If there are long holds, we won't be able to evict
2524                  * the objset.
2525                  */
2526                 if (dsl_dataset_long_held(ds)) {
2527                         err = SET_ERROR(EBUSY);
2528                         goto out;
2529                 }
2530
2531                 /* Check that the snapshot name does not conflict */
2532                 VERIFY0(dsl_dataset_get_snapname(ds));
2533                 if (strlen(ds->ds_snapname) >= max_snap_len) {
2534                         err = SET_ERROR(ENAMETOOLONG);
2535                         goto out;
2536                 }
2537                 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2538                 if (err == 0) {
2539                         (void) strcpy(ddpa->err_ds, snap->ds->ds_snapname);
2540                         err = SET_ERROR(EEXIST);
2541                         goto out;
2542                 }
2543                 if (err != ENOENT)
2544                         goto out;
2545
2546                 /* The very first snapshot does not have a deadlist */
2547                 if (dsl_dataset_phys(ds)->ds_prev_snap_obj == 0)
2548                         continue;
2549
2550                 dsl_deadlist_space(&ds->ds_deadlist,
2551                     &dlused, &dlcomp, &dluncomp);
2552                 ddpa->used += dlused;
2553                 ddpa->comp += dlcomp;
2554                 ddpa->uncomp += dluncomp;
2555         }
2556
2557         /*
2558          * If we are a clone of a clone then we never reached ORIGIN,
2559          * so we need to subtract out the clone origin's used space.
2560          */
2561         if (ddpa->origin_origin) {
2562                 ddpa->used -=
2563                     dsl_dataset_phys(ddpa->origin_origin)->ds_referenced_bytes;
2564                 ddpa->comp -=
2565                     dsl_dataset_phys(ddpa->origin_origin)->ds_compressed_bytes;
2566                 ddpa->uncomp -=
2567                     dsl_dataset_phys(ddpa->origin_origin)->
2568                     ds_uncompressed_bytes;
2569         }
2570
2571         /* Check that there is enough space and limit headroom here */
2572         err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2573             0, ss_mv_cnt, ddpa->used, ddpa->cr);
2574         if (err != 0)
2575                 goto out;
2576
2577         /*
2578          * Compute the amounts of space that will be used by snapshots
2579          * after the promotion (for both origin and clone).  For each,
2580          * it is the amount of space that will be on all of their
2581          * deadlists (that was not born before their new origin).
2582          */
2583         if (dsl_dir_phys(hds->ds_dir)->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2584                 uint64_t space;
2585
2586                 /*
2587                  * Note, typically this will not be a clone of a clone,
2588                  * so dd_origin_txg will be < TXG_INITIAL, so
2589                  * these snaplist_space() -> dsl_deadlist_space_range()
2590                  * calls will be fast because they do not have to
2591                  * iterate over all bps.
2592                  */
2593                 snap = list_head(&ddpa->origin_snaps);
2594                 err = snaplist_space(&ddpa->shared_snaps,
2595                     snap->ds->ds_dir->dd_origin_txg, &ddpa->cloneusedsnap);
2596                 if (err != 0)
2597                         goto out;
2598
2599                 err = snaplist_space(&ddpa->clone_snaps,
2600                     snap->ds->ds_dir->dd_origin_txg, &space);
2601                 if (err != 0)
2602                         goto out;
2603                 ddpa->cloneusedsnap += space;
2604         }
2605         if (dsl_dir_phys(origin_ds->ds_dir)->dd_flags &
2606             DD_FLAG_USED_BREAKDOWN) {
2607                 err = snaplist_space(&ddpa->origin_snaps,
2608                     dsl_dataset_phys(origin_ds)->ds_creation_txg,
2609                     &ddpa->originusedsnap);
2610                 if (err != 0)
2611                         goto out;
2612         }
2613
2614 out:
2615         promote_rele(ddpa, FTAG);
2616         return (err);
2617 }
2618
2619 static void
2620 dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
2621 {
2622         dsl_dataset_promote_arg_t *ddpa = arg;
2623         dsl_pool_t *dp = dmu_tx_pool(tx);
2624         dsl_dataset_t *hds;
2625         struct promotenode *snap;
2626         dsl_dataset_t *origin_ds;
2627         dsl_dataset_t *origin_head;
2628         dsl_dir_t *dd;
2629         dsl_dir_t *odd = NULL;
2630         uint64_t oldnext_obj;
2631         int64_t delta;
2632 #if defined(__FreeBSD__) && defined(_KERNEL)
2633         char *oldname, *newname;
2634 #endif
2635
2636         VERIFY0(promote_hold(ddpa, dp, FTAG));
2637         hds = ddpa->ddpa_clone;
2638
2639         ASSERT0(dsl_dataset_phys(hds)->ds_flags & DS_FLAG_NOPROMOTE);
2640
2641         snap = list_head(&ddpa->shared_snaps);
2642         origin_ds = snap->ds;
2643         dd = hds->ds_dir;
2644
2645         snap = list_head(&ddpa->origin_snaps);
2646         origin_head = snap->ds;
2647
2648         /*
2649          * We need to explicitly open odd, since origin_ds's dd will be
2650          * changing.
2651          */
2652         VERIFY0(dsl_dir_hold_obj(dp, origin_ds->ds_dir->dd_object,
2653             NULL, FTAG, &odd));
2654
2655         /* change origin's next snap */
2656         dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2657         oldnext_obj = dsl_dataset_phys(origin_ds)->ds_next_snap_obj;
2658         snap = list_tail(&ddpa->clone_snaps);
2659         ASSERT3U(dsl_dataset_phys(snap->ds)->ds_prev_snap_obj, ==,
2660             origin_ds->ds_object);
2661         dsl_dataset_phys(origin_ds)->ds_next_snap_obj = snap->ds->ds_object;
2662
2663         /* change the origin's next clone */
2664         if (dsl_dataset_phys(origin_ds)->ds_next_clones_obj) {
2665                 dsl_dataset_remove_from_next_clones(origin_ds,
2666                     snap->ds->ds_object, tx);
2667                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2668                     dsl_dataset_phys(origin_ds)->ds_next_clones_obj,
2669                     oldnext_obj, tx));
2670         }
2671
2672         /* change origin */
2673         dmu_buf_will_dirty(dd->dd_dbuf, tx);
2674         ASSERT3U(dsl_dir_phys(dd)->dd_origin_obj, ==, origin_ds->ds_object);
2675         dsl_dir_phys(dd)->dd_origin_obj = dsl_dir_phys(odd)->dd_origin_obj;
2676         dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2677         dmu_buf_will_dirty(odd->dd_dbuf, tx);
2678         dsl_dir_phys(odd)->dd_origin_obj = origin_ds->ds_object;
2679         origin_head->ds_dir->dd_origin_txg =
2680             dsl_dataset_phys(origin_ds)->ds_creation_txg;
2681
2682         /* change dd_clone entries */
2683         if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2684                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2685                     dsl_dir_phys(odd)->dd_clones, hds->ds_object, tx));
2686                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2687                     dsl_dir_phys(ddpa->origin_origin->ds_dir)->dd_clones,
2688                     hds->ds_object, tx));
2689
2690                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2691                     dsl_dir_phys(ddpa->origin_origin->ds_dir)->dd_clones,
2692                     origin_head->ds_object, tx));
2693                 if (dsl_dir_phys(dd)->dd_clones == 0) {
2694                         dsl_dir_phys(dd)->dd_clones =
2695                             zap_create(dp->dp_meta_objset, DMU_OT_DSL_CLONES,
2696                             DMU_OT_NONE, 0, tx);
2697                 }
2698                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2699                     dsl_dir_phys(dd)->dd_clones, origin_head->ds_object, tx));
2700         }
2701
2702 #if defined(__FreeBSD__) && defined(_KERNEL)
2703         /* Take the spa_namespace_lock early so zvol renames don't deadlock. */
2704         mutex_enter(&spa_namespace_lock);
2705
2706         oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2707         newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2708 #endif
2709
2710         /* move snapshots to this dir */
2711         for (snap = list_head(&ddpa->shared_snaps); snap;
2712             snap = list_next(&ddpa->shared_snaps, snap)) {
2713                 dsl_dataset_t *ds = snap->ds;
2714
2715                 /*
2716                  * Property callbacks are registered to a particular
2717                  * dsl_dir.  Since ours is changing, evict the objset
2718                  * so that they will be unregistered from the old dsl_dir.
2719                  */
2720                 if (ds->ds_objset) {
2721                         dmu_objset_evict(ds->ds_objset);
2722                         ds->ds_objset = NULL;
2723                 }
2724
2725                 /* move snap name entry */
2726                 VERIFY0(dsl_dataset_get_snapname(ds));
2727                 VERIFY0(dsl_dataset_snap_remove(origin_head,
2728                     ds->ds_snapname, tx, B_TRUE));
2729                 VERIFY0(zap_add(dp->dp_meta_objset,
2730                     dsl_dataset_phys(hds)->ds_snapnames_zapobj, ds->ds_snapname,
2731                     8, 1, &ds->ds_object, tx));
2732                 dsl_fs_ss_count_adjust(hds->ds_dir, 1,
2733                     DD_FIELD_SNAPSHOT_COUNT, tx);
2734
2735                 /* change containing dsl_dir */
2736                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2737                 ASSERT3U(dsl_dataset_phys(ds)->ds_dir_obj, ==, odd->dd_object);
2738                 dsl_dataset_phys(ds)->ds_dir_obj = dd->dd_object;
2739                 ASSERT3P(ds->ds_dir, ==, odd);
2740                 dsl_dir_rele(ds->ds_dir, ds);
2741                 VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
2742                     NULL, ds, &ds->ds_dir));
2743
2744 #if defined(__FreeBSD__) && defined(_KERNEL)
2745                 dsl_dataset_name(ds, newname);
2746                 zfsvfs_update_fromname(oldname, newname);
2747                 zvol_rename_minors(oldname, newname);
2748 #endif
2749
2750                 /* move any clone references */
2751                 if (dsl_dataset_phys(ds)->ds_next_clones_obj &&
2752                     spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2753                         zap_cursor_t zc;
2754                         zap_attribute_t za;
2755
2756                         for (zap_cursor_init(&zc, dp->dp_meta_objset,
2757                             dsl_dataset_phys(ds)->ds_next_clones_obj);
2758                             zap_cursor_retrieve(&zc, &za) == 0;
2759                             zap_cursor_advance(&zc)) {
2760                                 dsl_dataset_t *cnds;
2761                                 uint64_t o;
2762
2763                                 if (za.za_first_integer == oldnext_obj) {
2764                                         /*
2765                                          * We've already moved the
2766                                          * origin's reference.
2767                                          */
2768                                         continue;
2769                                 }
2770
2771                                 VERIFY0(dsl_dataset_hold_obj(dp,
2772                                     za.za_first_integer, FTAG, &cnds));
2773                                 o = dsl_dir_phys(cnds->ds_dir)->
2774                                     dd_head_dataset_obj;
2775
2776                                 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2777                                     dsl_dir_phys(odd)->dd_clones, o, tx));
2778                                 VERIFY0(zap_add_int(dp->dp_meta_objset,
2779                                     dsl_dir_phys(dd)->dd_clones, o, tx));
2780                                 dsl_dataset_rele(cnds, FTAG);
2781                         }
2782                         zap_cursor_fini(&zc);
2783                 }
2784
2785                 ASSERT(!dsl_prop_hascb(ds));
2786         }
2787
2788 #if defined(__FreeBSD__) && defined(_KERNEL)
2789         mutex_exit(&spa_namespace_lock);
2790
2791         kmem_free(newname, MAXPATHLEN);
2792         kmem_free(oldname, MAXPATHLEN);
2793 #endif
2794         /*
2795          * Change space accounting.
2796          * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2797          * both be valid, or both be 0 (resulting in delta == 0).  This
2798          * is true for each of {clone,origin} independently.
2799          */
2800
2801         delta = ddpa->cloneusedsnap -
2802             dsl_dir_phys(dd)->dd_used_breakdown[DD_USED_SNAP];
2803         ASSERT3S(delta, >=, 0);
2804         ASSERT3U(ddpa->used, >=, delta);
2805         dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2806         dsl_dir_diduse_space(dd, DD_USED_HEAD,
2807             ddpa->used - delta, ddpa->comp, ddpa->uncomp, tx);
2808
2809         delta = ddpa->originusedsnap -
2810             dsl_dir_phys(odd)->dd_used_breakdown[DD_USED_SNAP];
2811         ASSERT3S(delta, <=, 0);
2812         ASSERT3U(ddpa->used, >=, -delta);
2813         dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2814         dsl_dir_diduse_space(odd, DD_USED_HEAD,
2815             -ddpa->used - delta, -ddpa->comp, -ddpa->uncomp, tx);
2816
2817         dsl_dataset_phys(origin_ds)->ds_unique_bytes = ddpa->unique;
2818
2819         /* log history record */
2820         spa_history_log_internal_ds(hds, "promote", tx, "");
2821
2822         dsl_dir_rele(odd, FTAG);
2823         promote_rele(ddpa, FTAG);
2824 }
2825
2826 /*
2827  * Make a list of dsl_dataset_t's for the snapshots between first_obj
2828  * (exclusive) and last_obj (inclusive).  The list will be in reverse
2829  * order (last_obj will be the list_head()).  If first_obj == 0, do all
2830  * snapshots back to this dataset's origin.
2831  */
2832 static int
2833 snaplist_make(dsl_pool_t *dp,
2834     uint64_t first_obj, uint64_t last_obj, list_t *l, void *tag)
2835 {
2836         uint64_t obj = last_obj;
2837
2838         list_create(l, sizeof (struct promotenode),
2839             offsetof(struct promotenode, link));
2840
2841         while (obj != first_obj) {
2842                 dsl_dataset_t *ds;
2843                 struct promotenode *snap;
2844                 int err;
2845
2846                 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
2847                 ASSERT(err != ENOENT);
2848                 if (err != 0)
2849                         return (err);
2850
2851                 if (first_obj == 0)
2852                         first_obj = dsl_dir_phys(ds->ds_dir)->dd_origin_obj;
2853
2854                 snap = kmem_alloc(sizeof (*snap), KM_SLEEP);
2855                 snap->ds = ds;
2856                 list_insert_tail(l, snap);
2857                 obj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
2858         }
2859
2860         return (0);
2861 }
2862
2863 static int
2864 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2865 {
2866         struct promotenode *snap;
2867
2868         *spacep = 0;
2869         for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2870                 uint64_t used, comp, uncomp;
2871                 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2872                     mintxg, UINT64_MAX, &used, &comp, &uncomp);
2873                 *spacep += used;
2874         }
2875         return (0);
2876 }
2877
2878 static void
2879 snaplist_destroy(list_t *l, void *tag)
2880 {
2881         struct promotenode *snap;
2882
2883         if (l == NULL || !list_link_active(&l->list_head))
2884                 return;
2885
2886         while ((snap = list_tail(l)) != NULL) {
2887                 list_remove(l, snap);
2888                 dsl_dataset_rele(snap->ds, tag);
2889                 kmem_free(snap, sizeof (*snap));
2890         }
2891         list_destroy(l);
2892 }
2893
2894 static int
2895 promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp, void *tag)
2896 {
2897         int error;
2898         dsl_dir_t *dd;
2899         struct promotenode *snap;
2900
2901         error = dsl_dataset_hold(dp, ddpa->ddpa_clonename, tag,
2902             &ddpa->ddpa_clone);
2903         if (error != 0)
2904                 return (error);
2905         dd = ddpa->ddpa_clone->ds_dir;
2906
2907         if (ddpa->ddpa_clone->ds_is_snapshot ||
2908             !dsl_dir_is_clone(dd)) {
2909                 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2910                 return (SET_ERROR(EINVAL));
2911         }
2912
2913         error = snaplist_make(dp, 0, dsl_dir_phys(dd)->dd_origin_obj,
2914             &ddpa->shared_snaps, tag);
2915         if (error != 0)
2916                 goto out;
2917
2918         error = snaplist_make(dp, 0, ddpa->ddpa_clone->ds_object,
2919             &ddpa->clone_snaps, tag);
2920         if (error != 0)
2921                 goto out;
2922
2923         snap = list_head(&ddpa->shared_snaps);
2924         ASSERT3U(snap->ds->ds_object, ==, dsl_dir_phys(dd)->dd_origin_obj);
2925         error = snaplist_make(dp, dsl_dir_phys(dd)->dd_origin_obj,
2926             dsl_dir_phys(snap->ds->ds_dir)->dd_head_dataset_obj,
2927             &ddpa->origin_snaps, tag);
2928         if (error != 0)
2929                 goto out;
2930
2931         if (dsl_dir_phys(snap->ds->ds_dir)->dd_origin_obj != 0) {
2932                 error = dsl_dataset_hold_obj(dp,
2933                     dsl_dir_phys(snap->ds->ds_dir)->dd_origin_obj,
2934                     tag, &ddpa->origin_origin);
2935                 if (error != 0)
2936                         goto out;
2937         }
2938 out:
2939         if (error != 0)
2940                 promote_rele(ddpa, tag);
2941         return (error);
2942 }
2943
2944 static void
2945 promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag)
2946 {
2947         snaplist_destroy(&ddpa->shared_snaps, tag);
2948         snaplist_destroy(&ddpa->clone_snaps, tag);
2949         snaplist_destroy(&ddpa->origin_snaps, tag);
2950         if (ddpa->origin_origin != NULL)
2951                 dsl_dataset_rele(ddpa->origin_origin, tag);
2952         dsl_dataset_rele(ddpa->ddpa_clone, tag);
2953 }
2954
2955 /*
2956  * Promote a clone.
2957  *
2958  * If it fails due to a conflicting snapshot name, "conflsnap" will be filled
2959  * in with the name.  (It must be at least ZFS_MAX_DATASET_NAME_LEN bytes long.)
2960  */
2961 int
2962 dsl_dataset_promote(const char *name, char *conflsnap)
2963 {
2964         dsl_dataset_promote_arg_t ddpa = { 0 };
2965         uint64_t numsnaps;
2966         int error;
2967         objset_t *os;
2968
2969         /*
2970          * We will modify space proportional to the number of
2971          * snapshots.  Compute numsnaps.
2972          */
2973         error = dmu_objset_hold(name, FTAG, &os);
2974         if (error != 0)
2975                 return (error);
2976         error = zap_count(dmu_objset_pool(os)->dp_meta_objset,
2977             dsl_dataset_phys(dmu_objset_ds(os))->ds_snapnames_zapobj,
2978             &numsnaps);
2979         dmu_objset_rele(os, FTAG);
2980         if (error != 0)
2981                 return (error);
2982
2983         ddpa.ddpa_clonename = name;
2984         ddpa.err_ds = conflsnap;
2985         ddpa.cr = CRED();
2986
2987         return (dsl_sync_task(name, dsl_dataset_promote_check,
2988             dsl_dataset_promote_sync, &ddpa,
2989             2 + numsnaps, ZFS_SPACE_CHECK_RESERVED));
2990 }
2991
2992 int
2993 dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
2994     dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx)
2995 {
2996         /*
2997          * "slack" factor for received datasets with refquota set on them.
2998          * See the bottom of this function for details on its use.
2999          */
3000         uint64_t refquota_slack = DMU_MAX_ACCESS * spa_asize_inflation;
3001         int64_t unused_refres_delta;
3002
3003         /* they should both be heads */
3004         if (clone->ds_is_snapshot ||
3005             origin_head->ds_is_snapshot)
3006                 return (SET_ERROR(EINVAL));
3007
3008         /* if we are not forcing, the branch point should be just before them */
3009         if (!force && clone->ds_prev != origin_head->ds_prev)
3010                 return (SET_ERROR(EINVAL));
3011
3012         /* clone should be the clone (unless they are unrelated) */
3013         if (clone->ds_prev != NULL &&
3014             clone->ds_prev != clone->ds_dir->dd_pool->dp_origin_snap &&
3015             origin_head->ds_dir != clone->ds_prev->ds_dir)
3016                 return (SET_ERROR(EINVAL));
3017
3018         /* the clone should be a child of the origin */
3019         if (clone->ds_dir->dd_parent != origin_head->ds_dir)
3020                 return (SET_ERROR(EINVAL));
3021
3022         /* origin_head shouldn't be modified unless 'force' */
3023         if (!force &&
3024             dsl_dataset_modified_since_snap(origin_head, origin_head->ds_prev))
3025                 return (SET_ERROR(ETXTBSY));
3026
3027         /* origin_head should have no long holds (e.g. is not mounted) */
3028         if (dsl_dataset_handoff_check(origin_head, owner, tx))
3029                 return (SET_ERROR(EBUSY));
3030
3031         /* check amount of any unconsumed refreservation */
3032         unused_refres_delta =
3033             (int64_t)MIN(origin_head->ds_reserved,
3034             dsl_dataset_phys(origin_head)->ds_unique_bytes) -
3035             (int64_t)MIN(origin_head->ds_reserved,
3036             dsl_dataset_phys(clone)->ds_unique_bytes);
3037
3038         if (unused_refres_delta > 0 &&
3039             unused_refres_delta >
3040             dsl_dir_space_available(origin_head->ds_dir, NULL, 0, TRUE))
3041                 return (SET_ERROR(ENOSPC));
3042
3043         /*
3044          * The clone can't be too much over the head's refquota.
3045          *
3046          * To ensure that the entire refquota can be used, we allow one
3047          * transaction to exceed the the refquota.  Therefore, this check
3048          * needs to also allow for the space referenced to be more than the
3049          * refquota.  The maximum amount of space that one transaction can use
3050          * on disk is DMU_MAX_ACCESS * spa_asize_inflation.  Allowing this
3051          * overage ensures that we are able to receive a filesystem that
3052          * exceeds the refquota on the source system.
3053          *
3054          * So that overage is the refquota_slack we use below.
3055          */
3056         if (origin_head->ds_quota != 0 &&
3057             dsl_dataset_phys(clone)->ds_referenced_bytes >
3058             origin_head->ds_quota + refquota_slack)
3059                 return (SET_ERROR(EDQUOT));
3060
3061         return (0);
3062 }
3063
3064 void
3065 dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
3066     dsl_dataset_t *origin_head, dmu_tx_t *tx)
3067 {
3068         dsl_pool_t *dp = dmu_tx_pool(tx);
3069         int64_t unused_refres_delta;
3070
3071         ASSERT(clone->ds_reserved == 0);
3072         /*
3073          * NOTE: On DEBUG kernels there could be a race between this and
3074          * the check function if spa_asize_inflation is adjusted...
3075          */
3076         ASSERT(origin_head->ds_quota == 0 ||
3077             dsl_dataset_phys(clone)->ds_unique_bytes <= origin_head->ds_quota +
3078             DMU_MAX_ACCESS * spa_asize_inflation);
3079         ASSERT3P(clone->ds_prev, ==, origin_head->ds_prev);
3080
3081         /*
3082          * Swap per-dataset feature flags.
3083          */
3084         for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
3085                 if (!(spa_feature_table[f].fi_flags &
3086                     ZFEATURE_FLAG_PER_DATASET)) {
3087                         ASSERT(!clone->ds_feature_inuse[f]);
3088                         ASSERT(!origin_head->ds_feature_inuse[f]);
3089                         continue;
3090                 }
3091
3092                 boolean_t clone_inuse = clone->ds_feature_inuse[f];
3093                 boolean_t origin_head_inuse = origin_head->ds_feature_inuse[f];
3094
3095                 if (clone_inuse) {
3096                         dsl_dataset_deactivate_feature(clone->ds_object, f, tx);
3097                         clone->ds_feature_inuse[f] = B_FALSE;
3098                 }
3099                 if (origin_head_inuse) {
3100                         dsl_dataset_deactivate_feature(origin_head->ds_object,
3101                             f, tx);
3102                         origin_head->ds_feature_inuse[f] = B_FALSE;
3103                 }
3104                 if (clone_inuse) {
3105                         dsl_dataset_activate_feature(origin_head->ds_object,
3106                             f, tx);
3107                         origin_head->ds_feature_inuse[f] = B_TRUE;
3108                 }
3109                 if (origin_head_inuse) {
3110                         dsl_dataset_activate_feature(clone->ds_object, f, tx);
3111                         clone->ds_feature_inuse[f] = B_TRUE;
3112                 }
3113         }
3114
3115         dmu_buf_will_dirty(clone->ds_dbuf, tx);
3116         dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
3117
3118         if (clone->ds_objset != NULL) {
3119                 dmu_objset_evict(clone->ds_objset);
3120                 clone->ds_objset = NULL;
3121         }
3122
3123         if (origin_head->ds_objset != NULL) {
3124                 dmu_objset_evict(origin_head->ds_objset);
3125                 origin_head->ds_objset = NULL;
3126         }
3127
3128         unused_refres_delta =
3129             (int64_t)MIN(origin_head->ds_reserved,
3130             dsl_dataset_phys(origin_head)->ds_unique_bytes) -
3131             (int64_t)MIN(origin_head->ds_reserved,
3132             dsl_dataset_phys(clone)->ds_unique_bytes);
3133
3134         /*
3135          * Reset origin's unique bytes, if it exists.
3136          */
3137         if (clone->ds_prev) {
3138                 dsl_dataset_t *origin = clone->ds_prev;
3139                 uint64_t comp, uncomp;
3140
3141                 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3142                 dsl_deadlist_space_range(&clone->ds_deadlist,
3143                     dsl_dataset_phys(origin)->ds_prev_snap_txg, UINT64_MAX,
3144                     &dsl_dataset_phys(origin)->ds_unique_bytes, &comp, &uncomp);
3145         }
3146
3147         /* swap blkptrs */
3148         {
3149                 rrw_enter(&clone->ds_bp_rwlock, RW_WRITER, FTAG);
3150                 rrw_enter(&origin_head->ds_bp_rwlock, RW_WRITER, FTAG);
3151                 blkptr_t tmp;
3152                 tmp = dsl_dataset_phys(origin_head)->ds_bp;
3153                 dsl_dataset_phys(origin_head)->ds_bp =
3154                     dsl_dataset_phys(clone)->ds_bp;
3155                 dsl_dataset_phys(clone)->ds_bp = tmp;
3156                 rrw_exit(&origin_head->ds_bp_rwlock, FTAG);
3157                 rrw_exit(&clone->ds_bp_rwlock, FTAG);
3158         }
3159
3160         /* set dd_*_bytes */
3161         {
3162                 int64_t dused, dcomp, duncomp;
3163                 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3164                 uint64_t odl_used, odl_comp, odl_uncomp;
3165
3166                 ASSERT3U(dsl_dir_phys(clone->ds_dir)->
3167                     dd_used_breakdown[DD_USED_SNAP], ==, 0);
3168
3169                 dsl_deadlist_space(&clone->ds_deadlist,
3170                     &cdl_used, &cdl_comp, &cdl_uncomp);
3171                 dsl_deadlist_space(&origin_head->ds_deadlist,
3172                     &odl_used, &odl_comp, &odl_uncomp);
3173
3174                 dused = dsl_dataset_phys(clone)->ds_referenced_bytes +
3175                     cdl_used -
3176                     (dsl_dataset_phys(origin_head)->ds_referenced_bytes +
3177                     odl_used);
3178                 dcomp = dsl_dataset_phys(clone)->ds_compressed_bytes +
3179                     cdl_comp -
3180                     (dsl_dataset_phys(origin_head)->ds_compressed_bytes +
3181                     odl_comp);
3182                 duncomp = dsl_dataset_phys(clone)->ds_uncompressed_bytes +
3183                     cdl_uncomp -
3184                     (dsl_dataset_phys(origin_head)->ds_uncompressed_bytes +
3185                     odl_uncomp);
3186
3187                 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_HEAD,
3188                     dused, dcomp, duncomp, tx);
3189                 dsl_dir_diduse_space(clone->ds_dir, DD_USED_HEAD,
3190                     -dused, -dcomp, -duncomp, tx);
3191
3192                 /*
3193                  * The difference in the space used by snapshots is the
3194                  * difference in snapshot space due to the head's
3195                  * deadlist (since that's the only thing that's
3196                  * changing that affects the snapused).
3197                  */
3198                 dsl_deadlist_space_range(&clone->ds_deadlist,
3199                     origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
3200                     &cdl_used, &cdl_comp, &cdl_uncomp);
3201                 dsl_deadlist_space_range(&origin_head->ds_deadlist,
3202                     origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
3203                     &odl_used, &odl_comp, &odl_uncomp);
3204                 dsl_dir_transfer_space(origin_head->ds_dir, cdl_used - odl_used,
3205                     DD_USED_HEAD, DD_USED_SNAP, NULL);
3206         }
3207
3208         /* swap ds_*_bytes */
3209         SWITCH64(dsl_dataset_phys(origin_head)->ds_referenced_bytes,
3210             dsl_dataset_phys(clone)->ds_referenced_bytes);
3211         SWITCH64(dsl_dataset_phys(origin_head)->ds_compressed_bytes,
3212             dsl_dataset_phys(clone)->ds_compressed_bytes);
3213         SWITCH64(dsl_dataset_phys(origin_head)->ds_uncompressed_bytes,
3214             dsl_dataset_phys(clone)->ds_uncompressed_bytes);
3215         SWITCH64(dsl_dataset_phys(origin_head)->ds_unique_bytes,
3216             dsl_dataset_phys(clone)->ds_unique_bytes);
3217
3218         /* apply any parent delta for change in unconsumed refreservation */
3219         dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_REFRSRV,
3220             unused_refres_delta, 0, 0, tx);
3221
3222         /*
3223          * Swap deadlists.
3224          */
3225         dsl_deadlist_close(&clone->ds_deadlist);
3226         dsl_deadlist_close(&origin_head->ds_deadlist);
3227         SWITCH64(dsl_dataset_phys(origin_head)->ds_deadlist_obj,
3228             dsl_dataset_phys(clone)->ds_deadlist_obj);
3229         dsl_deadlist_open(&clone->ds_deadlist, dp->dp_meta_objset,
3230             dsl_dataset_phys(clone)->ds_deadlist_obj);
3231         dsl_deadlist_open(&origin_head->ds_deadlist, dp->dp_meta_objset,
3232             dsl_dataset_phys(origin_head)->ds_deadlist_obj);
3233
3234         dsl_scan_ds_clone_swapped(origin_head, clone, tx);
3235
3236         spa_history_log_internal_ds(clone, "clone swap", tx,
3237             "parent=%s", origin_head->ds_dir->dd_myname);
3238 }
3239
3240 /*
3241  * Given a pool name and a dataset object number in that pool,
3242  * return the name of that dataset.
3243  */
3244 int
3245 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3246 {
3247         dsl_pool_t *dp;
3248         dsl_dataset_t *ds;
3249         int error;
3250
3251         error = dsl_pool_hold(pname, FTAG, &dp);
3252         if (error != 0)
3253                 return (error);
3254
3255         error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
3256         if (error == 0) {
3257                 dsl_dataset_name(ds, buf);
3258                 dsl_dataset_rele(ds, FTAG);
3259         }
3260         dsl_pool_rele(dp, FTAG);
3261
3262         return (error);
3263 }
3264
3265 int
3266 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3267     uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3268 {
3269         int error = 0;
3270
3271         ASSERT3S(asize, >, 0);
3272
3273         /*
3274          * *ref_rsrv is the portion of asize that will come from any
3275          * unconsumed refreservation space.
3276          */
3277         *ref_rsrv = 0;
3278
3279         mutex_enter(&ds->ds_lock);
3280         /*
3281          * Make a space adjustment for reserved bytes.
3282          */
3283         if (ds->ds_reserved > dsl_dataset_phys(ds)->ds_unique_bytes) {
3284                 ASSERT3U(*used, >=,
3285                     ds->ds_reserved - dsl_dataset_phys(ds)->ds_unique_bytes);
3286                 *used -=
3287                     (ds->ds_reserved - dsl_dataset_phys(ds)->ds_unique_bytes);
3288                 *ref_rsrv =
3289                     asize - MIN(asize, parent_delta(ds, asize + inflight));
3290         }
3291
3292         if (!check_quota || ds->ds_quota == 0) {
3293                 mutex_exit(&ds->ds_lock);
3294                 return (0);
3295         }
3296         /*
3297          * If they are requesting more space, and our current estimate
3298          * is over quota, they get to try again unless the actual
3299          * on-disk is over quota and there are no pending changes (which
3300          * may free up space for us).
3301          */
3302         if (dsl_dataset_phys(ds)->ds_referenced_bytes + inflight >=
3303             ds->ds_quota) {
3304                 if (inflight > 0 ||
3305                     dsl_dataset_phys(ds)->ds_referenced_bytes < ds->ds_quota)
3306                         error = SET_ERROR(ERESTART);
3307                 else
3308                         error = SET_ERROR(EDQUOT);
3309         }
3310         mutex_exit(&ds->ds_lock);
3311
3312         return (error);
3313 }
3314
3315 typedef struct dsl_dataset_set_qr_arg {
3316         const char *ddsqra_name;
3317         zprop_source_t ddsqra_source;
3318         uint64_t ddsqra_value;
3319 } dsl_dataset_set_qr_arg_t;
3320
3321
3322 /* ARGSUSED */
3323 static int
3324 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
3325 {
3326         dsl_dataset_set_qr_arg_t *ddsqra = arg;
3327         dsl_pool_t *dp = dmu_tx_pool(tx);
3328         dsl_dataset_t *ds;
3329         int error;
3330         uint64_t newval;
3331
3332         if (spa_version(dp->dp_spa) < SPA_VERSION_REFQUOTA)
3333                 return (SET_ERROR(ENOTSUP));
3334
3335         error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
3336         if (error != 0)
3337                 return (error);
3338
3339         if (ds->ds_is_snapshot) {
3340                 dsl_dataset_rele(ds, FTAG);
3341                 return (SET_ERROR(EINVAL));
3342         }
3343
3344         error = dsl_prop_predict(ds->ds_dir,
3345             zfs_prop_to_name(ZFS_PROP_REFQUOTA),
3346             ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
3347         if (error != 0) {
3348                 dsl_dataset_rele(ds, FTAG);
3349                 return (error);
3350         }
3351
3352         if (newval == 0) {
3353                 dsl_dataset_rele(ds, FTAG);
3354                 return (0);
3355         }
3356
3357         if (newval < dsl_dataset_phys(ds)->ds_referenced_bytes ||
3358             newval < ds->ds_reserved) {
3359                 dsl_dataset_rele(ds, FTAG);
3360                 return (SET_ERROR(ENOSPC));
3361         }
3362
3363         dsl_dataset_rele(ds, FTAG);
3364         return (0);
3365 }
3366
3367 static void
3368 dsl_dataset_set_refquota_sync(void *arg, dmu_tx_t *tx)
3369 {
3370         dsl_dataset_set_qr_arg_t *ddsqra = arg;
3371         dsl_pool_t *dp = dmu_tx_pool(tx);
3372         dsl_dataset_t *ds;
3373         uint64_t newval;
3374
3375         VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
3376
3377         dsl_prop_set_sync_impl(ds,
3378             zfs_prop_to_name(ZFS_PROP_REFQUOTA),
3379             ddsqra->ddsqra_source, sizeof (ddsqra->ddsqra_value), 1,
3380             &ddsqra->ddsqra_value, tx);
3381
3382         VERIFY0(dsl_prop_get_int_ds(ds,
3383             zfs_prop_to_name(ZFS_PROP_REFQUOTA), &newval));
3384
3385         if (ds->ds_quota != newval) {
3386                 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3387                 ds->ds_quota = newval;
3388         }
3389         dsl_dataset_rele(ds, FTAG);
3390 }
3391
3392 int
3393 dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
3394     uint64_t refquota)
3395 {
3396         dsl_dataset_set_qr_arg_t ddsqra;
3397
3398         ddsqra.ddsqra_name = dsname;
3399         ddsqra.ddsqra_source = source;
3400         ddsqra.ddsqra_value = refquota;
3401
3402         return (dsl_sync_task(dsname, dsl_dataset_set_refquota_check,
3403             dsl_dataset_set_refquota_sync, &ddsqra, 0, ZFS_SPACE_CHECK_NONE));
3404 }
3405
3406 static int
3407 dsl_dataset_set_refreservation_check(void *arg, dmu_tx_t *tx)
3408 {
3409         dsl_dataset_set_qr_arg_t *ddsqra = arg;
3410         dsl_pool_t *dp = dmu_tx_pool(tx);
3411         dsl_dataset_t *ds;
3412         int error;
3413         uint64_t newval, unique;
3414
3415         if (spa_version(dp->dp_spa) < SPA_VERSION_REFRESERVATION)
3416                 return (SET_ERROR(ENOTSUP));
3417
3418         error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
3419         if (error != 0)
3420                 return (error);
3421
3422         if (ds->ds_is_snapshot) {
3423                 dsl_dataset_rele(ds, FTAG);
3424                 return (SET_ERROR(EINVAL));
3425         }
3426
3427         error = dsl_prop_predict(ds->ds_dir,
3428             zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
3429             ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
3430         if (error != 0) {
3431                 dsl_dataset_rele(ds, FTAG);
3432                 return (error);
3433         }
3434
3435         /*
3436          * If we are doing the preliminary check in open context, the
3437          * space estimates may be inaccurate.
3438          */
3439         if (!dmu_tx_is_syncing(tx)) {
3440                 dsl_dataset_rele(ds, FTAG);
3441                 return (0);
3442         }
3443
3444         mutex_enter(&ds->ds_lock);
3445         if (!DS_UNIQUE_IS_ACCURATE(ds))
3446                 dsl_dataset_recalc_head_uniq(ds);
3447         unique = dsl_dataset_phys(ds)->ds_unique_bytes;
3448         mutex_exit(&ds->ds_lock);
3449
3450         if (MAX(unique, newval) > MAX(unique, ds->ds_reserved)) {
3451                 uint64_t delta = MAX(unique, newval) -
3452                     MAX(unique, ds->ds_reserved);
3453
3454                 if (delta >
3455                     dsl_dir_space_available(ds->ds_dir, NULL, 0, B_TRUE) ||
3456                     (ds->ds_quota > 0 && newval > ds->ds_quota)) {
3457                         dsl_dataset_rele(ds, FTAG);
3458                         return (SET_ERROR(ENOSPC));
3459                 }
3460         }
3461
3462         dsl_dataset_rele(ds, FTAG);
3463         return (0);
3464 }
3465
3466 void
3467 dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
3468     zprop_source_t source, uint64_t value, dmu_tx_t *tx)
3469 {
3470         uint64_t newval;
3471         uint64_t unique;
3472         int64_t delta;
3473
3474         dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
3475             source, sizeof (value), 1, &value, tx);
3476
3477         VERIFY0(dsl_prop_get_int_ds(ds,
3478             zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &newval));
3479
3480         dmu_buf_will_dirty(ds->ds_dbuf, tx);
3481         mutex_enter(&ds->ds_dir->dd_lock);
3482         mutex_enter(&ds->ds_lock);
3483         ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3484         unique = dsl_dataset_phys(ds)->ds_unique_bytes;
3485         delta = MAX(0, (int64_t)(newval - unique)) -
3486             MAX(0, (int64_t)(ds->ds_reserved - unique));
3487         ds->ds_reserved = newval;
3488         mutex_exit(&ds->ds_lock);
3489
3490         dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3491         mutex_exit(&ds->ds_dir->dd_lock);
3492 }
3493
3494 static void
3495 dsl_dataset_set_refreservation_sync(void *arg, dmu_tx_t *tx)
3496 {
3497         dsl_dataset_set_qr_arg_t *ddsqra = arg;
3498         dsl_pool_t *dp = dmu_tx_pool(tx);
3499         dsl_dataset_t *ds;
3500
3501         VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
3502         dsl_dataset_set_refreservation_sync_impl(ds,
3503             ddsqra->ddsqra_source, ddsqra->ddsqra_value, tx);
3504         dsl_dataset_rele(ds, FTAG);
3505 }
3506
3507 int
3508 dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
3509     uint64_t refreservation)
3510 {
3511         dsl_dataset_set_qr_arg_t ddsqra;
3512
3513         ddsqra.ddsqra_name = dsname;
3514         ddsqra.ddsqra_source = source;
3515         ddsqra.ddsqra_value = refreservation;
3516
3517         return (dsl_sync_task(dsname, dsl_dataset_set_refreservation_check,
3518             dsl_dataset_set_refreservation_sync, &ddsqra,
3519             0, ZFS_SPACE_CHECK_NONE));
3520 }
3521
3522 /*
3523  * Return (in *usedp) the amount of space written in new that is not
3524  * present in oldsnap.  New may be a snapshot or the head.  Old must be
3525  * a snapshot before new, in new's filesystem (or its origin).  If not then
3526  * fail and return EINVAL.
3527  *
3528  * The written space is calculated by considering two components:  First, we
3529  * ignore any freed space, and calculate the written as new's used space
3530  * minus old's used space.  Next, we add in the amount of space that was freed
3531  * between the two snapshots, thus reducing new's used space relative to old's.
3532  * Specifically, this is the space that was born before old->ds_creation_txg,
3533  * and freed before new (ie. on new's deadlist or a previous deadlist).
3534  *
3535  * space freed                         [---------------------]
3536  * snapshots                       ---O-------O--------O-------O------
3537  *                                         oldsnap            new
3538  */
3539 int
3540 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
3541     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
3542 {
3543         int err = 0;
3544         uint64_t snapobj;
3545         dsl_pool_t *dp = new->ds_dir->dd_pool;
3546
3547         ASSERT(dsl_pool_config_held(dp));
3548
3549         *usedp = 0;
3550         *usedp += dsl_dataset_phys(new)->ds_referenced_bytes;
3551         *usedp -= dsl_dataset_phys(oldsnap)->ds_referenced_bytes;
3552
3553         *compp = 0;
3554         *compp += dsl_dataset_phys(new)->ds_compressed_bytes;
3555         *compp -= dsl_dataset_phys(oldsnap)->ds_compressed_bytes;
3556
3557         *uncompp = 0;
3558         *uncompp += dsl_dataset_phys(new)->ds_uncompressed_bytes;
3559         *uncompp -= dsl_dataset_phys(oldsnap)->ds_uncompressed_bytes;
3560
3561         snapobj = new->ds_object;
3562         while (snapobj != oldsnap->ds_object) {
3563                 dsl_dataset_t *snap;
3564                 uint64_t used, comp, uncomp;
3565
3566                 if (snapobj == new->ds_object) {
3567                         snap = new;
3568                 } else {
3569                         err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
3570                         if (err != 0)
3571                                 break;
3572                 }
3573
3574                 if (dsl_dataset_phys(snap)->ds_prev_snap_txg ==
3575                     dsl_dataset_phys(oldsnap)->ds_creation_txg) {
3576                         /*
3577                          * The blocks in the deadlist can not be born after
3578                          * ds_prev_snap_txg, so get the whole deadlist space,
3579                          * which is more efficient (especially for old-format
3580                          * deadlists).  Unfortunately the deadlist code
3581                          * doesn't have enough information to make this
3582                          * optimization itself.
3583                          */
3584                         dsl_deadlist_space(&snap->ds_deadlist,
3585                             &used, &comp, &uncomp);
3586                 } else {
3587                         dsl_deadlist_space_range(&snap->ds_deadlist,
3588                             0, dsl_dataset_phys(oldsnap)->ds_creation_txg,
3589                             &used, &comp, &uncomp);
3590                 }
3591                 *usedp += used;
3592                 *compp += comp;
3593                 *uncompp += uncomp;
3594
3595                 /*
3596                  * If we get to the beginning of the chain of snapshots
3597                  * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
3598                  * was not a snapshot of/before new.
3599                  */
3600                 snapobj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
3601                 if (snap != new)
3602                         dsl_dataset_rele(snap, FTAG);
3603                 if (snapobj == 0) {
3604                         err = SET_ERROR(EINVAL);
3605                         break;
3606                 }
3607
3608         }
3609         return (err);
3610 }
3611
3612 /*
3613  * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
3614  * lastsnap, and all snapshots in between are deleted.
3615  *
3616  * blocks that would be freed            [---------------------------]
3617  * snapshots                       ---O-------O--------O-------O--------O
3618  *                                        firstsnap        lastsnap
3619  *
3620  * This is the set of blocks that were born after the snap before firstsnap,
3621  * (birth > firstsnap->prev_snap_txg) and died before the snap after the
3622  * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
3623  * We calculate this by iterating over the relevant deadlists (from the snap
3624  * after lastsnap, backward to the snap after firstsnap), summing up the
3625  * space on the deadlist that was born after the snap before firstsnap.
3626  */
3627 int
3628 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
3629     dsl_dataset_t *lastsnap,
3630     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
3631 {
3632         int err = 0;
3633         uint64_t snapobj;
3634         dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
3635
3636         ASSERT(firstsnap->ds_is_snapshot);
3637         ASSERT(lastsnap->ds_is_snapshot);
3638
3639         /*
3640          * Check that the snapshots are in the same dsl_dir, and firstsnap
3641          * is before lastsnap.
3642          */
3643         if (firstsnap->ds_dir != lastsnap->ds_dir ||
3644             dsl_dataset_phys(firstsnap)->ds_creation_txg >
3645             dsl_dataset_phys(lastsnap)->ds_creation_txg)
3646                 return (SET_ERROR(EINVAL));
3647
3648         *usedp = *compp = *uncompp = 0;
3649
3650         snapobj = dsl_dataset_phys(lastsnap)->ds_next_snap_obj;
3651         while (snapobj != firstsnap->ds_object) {
3652                 dsl_dataset_t *ds;
3653                 uint64_t used, comp, uncomp;
3654
3655                 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
3656                 if (err != 0)
3657                         break;
3658
3659                 dsl_deadlist_space_range(&ds->ds_deadlist,
3660                     dsl_dataset_phys(firstsnap)->ds_prev_snap_txg, UINT64_MAX,
3661                     &used, &comp, &uncomp);
3662                 *usedp += used;
3663                 *compp += comp;
3664                 *uncompp += uncomp;
3665
3666                 snapobj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
3667                 ASSERT3U(snapobj, !=, 0);
3668                 dsl_dataset_rele(ds, FTAG);
3669         }
3670         return (err);
3671 }
3672
3673 /*
3674  * Return TRUE if 'earlier' is an earlier snapshot in 'later's timeline.
3675  * For example, they could both be snapshots of the same filesystem, and
3676  * 'earlier' is before 'later'.  Or 'earlier' could be the origin of
3677  * 'later's filesystem.  Or 'earlier' could be an older snapshot in the origin's
3678  * filesystem.  Or 'earlier' could be the origin's origin.
3679  *
3680  * If non-zero, earlier_txg is used instead of earlier's ds_creation_txg.
3681  */
3682 boolean_t
3683 dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier,
3684     uint64_t earlier_txg)
3685 {
3686         dsl_pool_t *dp = later->ds_dir->dd_pool;
3687         int error;
3688         boolean_t ret;
3689
3690         ASSERT(dsl_pool_config_held(dp));
3691         ASSERT(earlier->ds_is_snapshot || earlier_txg != 0);
3692
3693         if (earlier_txg == 0)
3694                 earlier_txg = dsl_dataset_phys(earlier)->ds_creation_txg;
3695
3696         if (later->ds_is_snapshot &&
3697             earlier_txg >= dsl_dataset_phys(later)->ds_creation_txg)
3698                 return (B_FALSE);
3699
3700         if (later->ds_dir == earlier->ds_dir)
3701                 return (B_TRUE);
3702         if (!dsl_dir_is_clone(later->ds_dir))
3703                 return (B_FALSE);
3704
3705         if (dsl_dir_phys(later->ds_dir)->dd_origin_obj == earlier->ds_object)
3706                 return (B_TRUE);
3707         dsl_dataset_t *origin;
3708         error = dsl_dataset_hold_obj(dp,
3709             dsl_dir_phys(later->ds_dir)->dd_origin_obj, FTAG, &origin);
3710         if (error != 0)
3711                 return (B_FALSE);
3712         ret = dsl_dataset_is_before(origin, earlier, earlier_txg);
3713         dsl_dataset_rele(origin, FTAG);
3714         return (ret);
3715 }
3716
3717 void
3718 dsl_dataset_zapify(dsl_dataset_t *ds, dmu_tx_t *tx)
3719 {
3720         objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3721         dmu_object_zapify(mos, ds->ds_object, DMU_OT_DSL_DATASET, tx);
3722 }
3723
3724 boolean_t
3725 dsl_dataset_is_zapified(dsl_dataset_t *ds)
3726 {
3727         dmu_object_info_t doi;
3728
3729         dmu_object_info_from_db(ds->ds_dbuf, &doi);
3730         return (doi.doi_type == DMU_OTN_ZAP_METADATA);
3731 }
3732
3733 boolean_t
3734 dsl_dataset_has_resume_receive_state(dsl_dataset_t *ds)
3735 {
3736         return (dsl_dataset_is_zapified(ds) &&
3737             zap_contains(ds->ds_dir->dd_pool->dp_meta_objset,
3738             ds->ds_object, DS_FIELD_RESUME_TOGUID) == 0);
3739 }