module/zfs/bpobj.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
  24  * Copyright (c) 2017 Datto Inc.
  25  */
  26
  27 #include <sys/bpobj.h>
  28 #include <sys/zfs_context.h>
  29 #include <sys/refcount.h>
  30 #include <sys/dsl_pool.h>
  31 #include <sys/zfeature.h>
  32 #include <sys/zap.h>
  33
  34 /*
  35  * Return an empty bpobj, preferably the empty dummy one (dp_empty_bpobj).
  36  */
  37 uint64_t
  38 bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx)
  39 {
  40         spa_t *spa = dmu_objset_spa(os);
  41         dsl_pool_t *dp = dmu_objset_pool(os);
  42
  43         if (spa_feature_is_enabled(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
  44                 if (!spa_feature_is_active(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
  45                         ASSERT0(dp->dp_empty_bpobj);
  46                         dp->dp_empty_bpobj =
  47                             bpobj_alloc(os, SPA_OLD_MAXBLOCKSIZE, tx);
  48                         VERIFY(zap_add(os,
  49                             DMU_POOL_DIRECTORY_OBJECT,
  50                             DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
  51                             &dp->dp_empty_bpobj, tx) == 0);
  52                 }
  53                 spa_feature_incr(spa, SPA_FEATURE_EMPTY_BPOBJ, tx);
  54                 ASSERT(dp->dp_empty_bpobj != 0);
  55                 return (dp->dp_empty_bpobj);
  56         } else {
  57                 return (bpobj_alloc(os, blocksize, tx));
  58         }
  59 }
  60
  61 void
  62 bpobj_decr_empty(objset_t *os, dmu_tx_t *tx)
  63 {
  64         dsl_pool_t *dp = dmu_objset_pool(os);
  65
  66         spa_feature_decr(dmu_objset_spa(os), SPA_FEATURE_EMPTY_BPOBJ, tx);
  67         if (!spa_feature_is_active(dmu_objset_spa(os),
  68             SPA_FEATURE_EMPTY_BPOBJ)) {
  69                 VERIFY3U(0, ==, zap_remove(dp->dp_meta_objset,
  70                     DMU_POOL_DIRECTORY_OBJECT,
  71                     DMU_POOL_EMPTY_BPOBJ, tx));
  72                 VERIFY3U(0, ==, dmu_object_free(os, dp->dp_empty_bpobj, tx));
  73                 dp->dp_empty_bpobj = 0;
  74         }
  75 }
  76
  77 uint64_t
  78 bpobj_alloc(objset_t *os, int blocksize, dmu_tx_t *tx)
  79 {
  80         int size;
  81
  82         if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_BPOBJ_ACCOUNT)
  83                 size = BPOBJ_SIZE_V0;
  84         else if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
  85                 size = BPOBJ_SIZE_V1;
  86         else
  87                 size = sizeof (bpobj_phys_t);
  88
  89         return (dmu_object_alloc(os, DMU_OT_BPOBJ, blocksize,
  90             DMU_OT_BPOBJ_HDR, size, tx));
  91 }
  92
  93 void
  94 bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx)
  95 {
  96         int64_t i;
  97         bpobj_t bpo;
  98         dmu_object_info_t doi;
  99         int epb;
 100         dmu_buf_t *dbuf = NULL;
 101
 102         ASSERT(obj != dmu_objset_pool(os)->dp_empty_bpobj);
 103         VERIFY3U(0, ==, bpobj_open(&bpo, os, obj));
 104
 105         mutex_enter(&bpo.bpo_lock);
 106
 107         if (!bpo.bpo_havesubobj || bpo.bpo_phys->bpo_subobjs == 0)
 108                 goto out;
 109
 110         VERIFY3U(0, ==, dmu_object_info(os, bpo.bpo_phys->bpo_subobjs, &doi));
 111         epb = doi.doi_data_block_size / sizeof (uint64_t);
 112
 113         for (i = bpo.bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
 114                 uint64_t *objarray;
 115                 uint64_t offset, blkoff;
 116
 117                 offset = i * sizeof (uint64_t);
 118                 blkoff = P2PHASE(i, epb);
 119
 120                 if (dbuf == NULL || dbuf->db_offset > offset) {
 121                         if (dbuf)
 122                                 dmu_buf_rele(dbuf, FTAG);
 123                         VERIFY3U(0, ==, dmu_buf_hold(os,
 124                             bpo.bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0));
 125                 }
 126
 127                 ASSERT3U(offset, >=, dbuf->db_offset);
 128                 ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
 129
 130                 objarray = dbuf->db_data;
 131                 bpobj_free(os, objarray[blkoff], tx);
 132         }
 133         if (dbuf) {
 134                 dmu_buf_rele(dbuf, FTAG);
 135                 dbuf = NULL;
 136         }
 137         VERIFY3U(0, ==, dmu_object_free(os, bpo.bpo_phys->bpo_subobjs, tx));
 138
 139 out:
 140         mutex_exit(&bpo.bpo_lock);
 141         bpobj_close(&bpo);
 142
 143         VERIFY3U(0, ==, dmu_object_free(os, obj, tx));
 144 }
 145
 146 int
 147 bpobj_open(bpobj_t *bpo, objset_t *os, uint64_t object)
 148 {
 149         dmu_object_info_t doi;
 150         int err;
 151
 152         err = dmu_object_info(os, object, &doi);
 153         if (err)
 154                 return (err);
 155
 156         bzero(bpo, sizeof (*bpo));
 157         mutex_init(&bpo->bpo_lock, NULL, MUTEX_DEFAULT, NULL);
 158
 159         ASSERT(bpo->bpo_dbuf == NULL);
 160         ASSERT(bpo->bpo_phys == NULL);
 161         ASSERT(object != 0);
 162         ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ);
 163         ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPOBJ_HDR);
 164
 165         err = dmu_bonus_hold(os, object, bpo, &bpo->bpo_dbuf);
 166         if (err)
 167                 return (err);
 168
 169         bpo->bpo_os = os;
 170         bpo->bpo_object = object;
 171         bpo->bpo_epb = doi.doi_data_block_size >> SPA_BLKPTRSHIFT;
 172         bpo->bpo_havecomp = (doi.doi_bonus_size > BPOBJ_SIZE_V0);
 173         bpo->bpo_havesubobj = (doi.doi_bonus_size > BPOBJ_SIZE_V1);
 174         bpo->bpo_phys = bpo->bpo_dbuf->db_data;
 175         return (0);
 176 }
 177
 178 boolean_t
 179 bpobj_is_open(const bpobj_t *bpo)
 180 {
 181         return (bpo->bpo_object != 0);
 182 }
 183
 184 void
 185 bpobj_close(bpobj_t *bpo)
 186 {
 187         /* Lame workaround for closing a bpobj that was never opened. */
 188         if (bpo->bpo_object == 0)
 189                 return;
 190
 191         dmu_buf_rele(bpo->bpo_dbuf, bpo);
 192         if (bpo->bpo_cached_dbuf != NULL)
 193                 dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
 194         bpo->bpo_dbuf = NULL;
 195         bpo->bpo_phys = NULL;
 196         bpo->bpo_cached_dbuf = NULL;
 197         bpo->bpo_object = 0;
 198
 199         mutex_destroy(&bpo->bpo_lock);
 200 }
 201
 202 boolean_t
 203 bpobj_is_empty(bpobj_t *bpo)
 204 {
 205         return (bpo->bpo_phys->bpo_num_blkptrs == 0 &&
 206             (!bpo->bpo_havesubobj || bpo->bpo_phys->bpo_num_subobjs == 0));
 207 }
 208
 209 static int
 210 bpobj_iterate_impl(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx,
 211     boolean_t free)
 212 {
 213         dmu_object_info_t doi;
 214         int epb;
 215         int64_t i;
 216         int err = 0;
 217         dmu_buf_t *dbuf = NULL;
 218
 219         ASSERT(bpobj_is_open(bpo));
 220         mutex_enter(&bpo->bpo_lock);
 221
 222         if (free)
 223                 dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
 224
 225         for (i = bpo->bpo_phys->bpo_num_blkptrs - 1; i >= 0; i--) {
 226                 blkptr_t *bparray;
 227                 blkptr_t *bp;
 228                 uint64_t offset, blkoff;
 229
 230                 offset = i * sizeof (blkptr_t);
 231                 blkoff = P2PHASE(i, bpo->bpo_epb);
 232
 233                 if (dbuf == NULL || dbuf->db_offset > offset) {
 234                         if (dbuf)
 235                                 dmu_buf_rele(dbuf, FTAG);
 236                         err = dmu_buf_hold(bpo->bpo_os, bpo->bpo_object, offset,
 237                             FTAG, &dbuf, 0);
 238                         if (err)
 239                                 break;
 240                 }
 241
 242                 ASSERT3U(offset, >=, dbuf->db_offset);
 243                 ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
 244
 245                 bparray = dbuf->db_data;
 246                 bp = &bparray[blkoff];
 247                 err = func(arg, bp, tx);
 248                 if (err)
 249                         break;
 250                 if (free) {
 251                         bpo->bpo_phys->bpo_bytes -=
 252                             bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
 253                         ASSERT3S(bpo->bpo_phys->bpo_bytes, >=, 0);
 254                         if (bpo->bpo_havecomp) {
 255                                 bpo->bpo_phys->bpo_comp -= BP_GET_PSIZE(bp);
 256                                 bpo->bpo_phys->bpo_uncomp -= BP_GET_UCSIZE(bp);
 257                         }
 258                         bpo->bpo_phys->bpo_num_blkptrs--;
 259                         ASSERT3S(bpo->bpo_phys->bpo_num_blkptrs, >=, 0);
 260                 }
 261         }
 262         if (dbuf) {
 263                 dmu_buf_rele(dbuf, FTAG);
 264                 dbuf = NULL;
 265         }
 266         if (free) {
 267                 VERIFY3U(0, ==, dmu_free_range(bpo->bpo_os, bpo->bpo_object,
 268                     (i + 1) * sizeof (blkptr_t), DMU_OBJECT_END, tx));
 269         }
 270         if (err || !bpo->bpo_havesubobj || bpo->bpo_phys->bpo_subobjs == 0)
 271                 goto out;
 272
 273         ASSERT(bpo->bpo_havecomp);
 274         err = dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, &doi);
 275         if (err) {
 276                 mutex_exit(&bpo->bpo_lock);
 277                 return (err);
 278         }
 279         ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);
 280         epb = doi.doi_data_block_size / sizeof (uint64_t);
 281
 282         for (i = bpo->bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
 283                 uint64_t *objarray;
 284                 uint64_t offset, blkoff;
 285                 bpobj_t sublist;
 286                 uint64_t used_before, comp_before, uncomp_before;
 287                 uint64_t used_after, comp_after, uncomp_after;
 288
 289                 offset = i * sizeof (uint64_t);
 290                 blkoff = P2PHASE(i, epb);
 291
 292                 if (dbuf == NULL || dbuf->db_offset > offset) {
 293                         if (dbuf)
 294                                 dmu_buf_rele(dbuf, FTAG);
 295                         err = dmu_buf_hold(bpo->bpo_os,
 296                             bpo->bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0);
 297                         if (err)
 298                                 break;
 299                 }
 300
 301                 ASSERT3U(offset, >=, dbuf->db_offset);
 302                 ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
 303
 304                 objarray = dbuf->db_data;
 305                 err = bpobj_open(&sublist, bpo->bpo_os, objarray[blkoff]);
 306                 if (err)
 307                         break;
 308                 if (free) {
 309                         err = bpobj_space(&sublist,
 310                             &used_before, &comp_before, &uncomp_before);
 311                         if (err != 0) {
 312                                 bpobj_close(&sublist);
 313                                 break;
 314                         }
 315                 }
 316                 err = bpobj_iterate_impl(&sublist, func, arg, tx, free);
 317                 if (free) {
 318                         VERIFY3U(0, ==, bpobj_space(&sublist,
 319                             &used_after, &comp_after, &uncomp_after));
 320                         bpo->bpo_phys->bpo_bytes -= used_before - used_after;
 321                         ASSERT3S(bpo->bpo_phys->bpo_bytes, >=, 0);
 322                         bpo->bpo_phys->bpo_comp -= comp_before - comp_after;
 323                         bpo->bpo_phys->bpo_uncomp -=
 324                             uncomp_before - uncomp_after;
 325                 }
 326
 327                 bpobj_close(&sublist);
 328                 if (err)
 329                         break;
 330                 if (free) {
 331                         err = dmu_object_free(bpo->bpo_os,
 332                             objarray[blkoff], tx);
 333                         if (err)
 334                                 break;
 335                         bpo->bpo_phys->bpo_num_subobjs--;
 336                         ASSERT3S(bpo->bpo_phys->bpo_num_subobjs, >=, 0);
 337                 }
 338         }
 339         if (dbuf) {
 340                 dmu_buf_rele(dbuf, FTAG);
 341                 dbuf = NULL;
 342         }
 343         if (free) {
 344                 VERIFY3U(0, ==, dmu_free_range(bpo->bpo_os,
 345                     bpo->bpo_phys->bpo_subobjs,
 346                     (i + 1) * sizeof (uint64_t), DMU_OBJECT_END, tx));
 347         }
 348
 349 out:
 350         /* If there are no entries, there should be no bytes. */
 351         if (bpobj_is_empty(bpo)) {
 352                 ASSERT0(bpo->bpo_phys->bpo_bytes);
 353                 ASSERT0(bpo->bpo_phys->bpo_comp);
 354                 ASSERT0(bpo->bpo_phys->bpo_uncomp);
 355         }
 356
 357         mutex_exit(&bpo->bpo_lock);
 358         return (err);
 359 }
 360
 361 /*
 362  * Iterate and remove the entries.  If func returns nonzero, iteration
 363  * will stop and that entry will not be removed.
 364  */
 365 int
 366 bpobj_iterate(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
 367 {
 368         return (bpobj_iterate_impl(bpo, func, arg, tx, B_TRUE));
 369 }
 370
 371 /*
 372  * Iterate the entries.  If func returns nonzero, iteration will stop.
 373  */
 374 int
 375 bpobj_iterate_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
 376 {
 377         return (bpobj_iterate_impl(bpo, func, arg, tx, B_FALSE));
 378 }
 379
 380 /*
 381  * Logically add subobj's contents to the parent bpobj.
 382  *
 383  * In the most general case, this is accomplished in constant time by adding
 384  * a reference to subobj.  This case is used when enqueuing a large subobj:
 385  * +--------------+                        +--------------+
 386  * | bpobj        |----------------------->| subobj list  |
 387  * +----+----+----+----+----+              +-----+-----+--+--+
 388  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
 389  * +----+----+----+----+----+              +-----+-----+-----+
 390  *
 391  * +--------------+                        +--------------+
 392  * | sub-bpobj    |----------------------> | subsubobj    |
 393  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
 394  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
 395  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
 396  *
 397  * Result: sub-bpobj added to parent's subobj list.
 398  * +--------------+                        +--------------+
 399  * | bpobj        |----------------------->| subobj list  |
 400  * +----+----+----+----+----+              +-----+-----+--+--+-----+
 401  * | bp | bp | bp | bp | bp |              | obj | obj | obj | OBJ |
 402  * +----+----+----+----+----+              +-----+-----+-----+--|--+
 403  *                                                              |
 404  *       /-----------------------------------------------------/
 405  *       v
 406  * +--------------+                        +--------------+
 407  * | sub-bpobj    |----------------------> | subsubobj    |
 408  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
 409  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
 410  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
 411  *
 412  *
 413  * In a common case, the subobj is small: its bp's and its list of subobj's
 414  * are each stored in a single block.  In this case we copy the subobj's
 415  * contents to the parent:
 416  * +--------------+                        +--------------+
 417  * | bpobj        |----------------------->| subobj list  |
 418  * +----+----+----+----+----+              +-----+-----+--+--+
 419  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
 420  * +----+----+----+----+----+              +-----+-----+-----+
 421  *                          ^                                ^
 422  * +--------------+         |              +--------------+  |
 423  * | sub-bpobj    |---------^------------> | subsubobj    |  ^
 424  * +----+----+----+         |              +-----+-----+--+  |
 425  * | BP | BP |-->-->-->-->-/               | OBJ | OBJ |-->-/
 426  * +----+----+                             +-----+-----+
 427  *
 428  * Result: subobj destroyed, contents copied to parent:
 429  * +--------------+                        +--------------+
 430  * | bpobj        |----------------------->| subobj list  |
 431  * +----+----+----+----+----+----+----+    +-----+-----+--+--+-----+-----+
 432  * | bp | bp | bp | bp | bp | BP | BP |    | obj | obj | obj | OBJ | OBJ |
 433  * +----+----+----+----+----+----+----+    +-----+-----+-----+-----+-----+
 434  *
 435  *
 436  * If the subobj has many BP's but few subobj's, we can copy the sub-subobj's
 437  * but retain the sub-bpobj:
 438  * +--------------+                        +--------------+
 439  * | bpobj        |----------------------->| subobj list  |
 440  * +----+----+----+----+----+              +-----+-----+--+--+
 441  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
 442  * +----+----+----+----+----+              +-----+-----+-----+
 443  *                                                           ^
 444  * +--------------+                        +--------------+  |
 445  * | sub-bpobj    |----------------------> | subsubobj    |  ^
 446  * +----+----+----+----+---------+----+    +-----+-----+--+  |
 447  * | bp | bp | bp | bp |   ...   | bp |    | OBJ | OBJ |-->-/
 448  * +----+----+----+----+---------+----+    +-----+-----+
 449  *
 450  * Result: sub-sub-bpobjs and subobj added to parent's subobj list.
 451  * +--------------+                     +--------------+
 452  * | bpobj        |-------------------->| subobj list  |
 453  * +----+----+----+----+----+           +-----+-----+--+--+-----+-----+------+
 454  * | bp | bp | bp | bp | bp |           | obj | obj | obj | OBJ | OBJ | OBJ* |
 455  * +----+----+----+----+----+           +-----+-----+-----+-----+-----+--|---+
 456  *                                                                       |
 457  *       /--------------------------------------------------------------/
 458  *       v
 459  * +--------------+
 460  * | sub-bpobj    |
 461  * +----+----+----+----+---------+----+
 462  * | bp | bp | bp | bp |   ...   | bp |
 463  * +----+----+----+----+---------+----+
 464  */
 465 void
 466 bpobj_enqueue_subobj(bpobj_t *bpo, uint64_t subobj, dmu_tx_t *tx)
 467 {
 468         bpobj_t subbpo;
 469         uint64_t used, comp, uncomp, subsubobjs;
 470         boolean_t copy_subsub = B_TRUE;
 471         boolean_t copy_bps = B_TRUE;
 472
 473         ASSERT(bpobj_is_open(bpo));
 474         ASSERT(subobj != 0);
 475         ASSERT(bpo->bpo_havesubobj);
 476         ASSERT(bpo->bpo_havecomp);
 477         ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
 478
 479         if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj) {
 480                 bpobj_decr_empty(bpo->bpo_os, tx);
 481                 return;
 482         }
 483
 484         VERIFY3U(0, ==, bpobj_open(&subbpo, bpo->bpo_os, subobj));
 485         VERIFY3U(0, ==, bpobj_space(&subbpo, &used, &comp, &uncomp));
 486
 487         if (bpobj_is_empty(&subbpo)) {
 488                 /* No point in having an empty subobj. */
 489                 bpobj_close(&subbpo);
 490                 bpobj_free(bpo->bpo_os, subobj, tx);
 491                 return;
 492         }
 493
 494         mutex_enter(&bpo->bpo_lock);
 495         dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
 496
 497         dmu_object_info_t doi;
 498
 499         if (bpo->bpo_phys->bpo_subobjs != 0) {
 500                 ASSERT0(dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
 501                     &doi));
 502                 ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);
 503         }
 504
 505         /*
 506          * If subobj has only one block of subobjs, then move subobj's
 507          * subobjs to bpo's subobj list directly.  This reduces recursion in
 508          * bpobj_iterate due to nested subobjs.
 509          */
 510         subsubobjs = subbpo.bpo_phys->bpo_subobjs;
 511         if (subsubobjs != 0) {
 512                 VERIFY0(dmu_object_info(bpo->bpo_os, subsubobjs, &doi));
 513                 if (doi.doi_max_offset > doi.doi_data_block_size) {
 514                         copy_subsub = B_FALSE;
 515                 }
 516         }
 517
 518         /*
 519          * If, in addition to having only one block of subobj's, subobj has
 520          * only one block of bp's, then move subobj's bp's to bpo's bp list
 521          * directly. This reduces recursion in bpobj_iterate due to nested
 522          * subobjs.
 523          */
 524         VERIFY3U(0, ==, dmu_object_info(bpo->bpo_os, subobj, &doi));
 525         if (doi.doi_max_offset > doi.doi_data_block_size || !copy_subsub) {
 526                 copy_bps = B_FALSE;
 527         }
 528
 529         if (copy_subsub && subsubobjs != 0) {
 530                 dmu_buf_t *subdb;
 531                 uint64_t numsubsub = subbpo.bpo_phys->bpo_num_subobjs;
 532
 533                 VERIFY0(dmu_buf_hold(bpo->bpo_os, subsubobjs,
 534                     0, FTAG, &subdb, 0));
 535                 /*
 536                  * Make sure that we are not asking dmu_write()
 537                  * to write more data than we have in our buffer.
 538                  */
 539                 VERIFY3U(subdb->db_size, >=,
 540                     numsubsub * sizeof (subobj));
 541                 if (bpo->bpo_phys->bpo_subobjs == 0) {
 542                         bpo->bpo_phys->bpo_subobjs =
 543                             dmu_object_alloc(bpo->bpo_os,
 544                             DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
 545                             DMU_OT_NONE, 0, tx);
 546                 }
 547                 dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
 548                     bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
 549                     numsubsub * sizeof (subobj), subdb->db_data, tx);
 550                 dmu_buf_rele(subdb, FTAG);
 551                 bpo->bpo_phys->bpo_num_subobjs += numsubsub;
 552
 553                 dmu_buf_will_dirty(subbpo.bpo_dbuf, tx);
 554                 subbpo.bpo_phys->bpo_subobjs = 0;
 555                 VERIFY0(dmu_object_free(bpo->bpo_os, subsubobjs, tx));
 556         }
 557
 558         if (copy_bps) {
 559                 dmu_buf_t *bps;
 560                 uint64_t numbps = subbpo.bpo_phys->bpo_num_blkptrs;
 561
 562                 ASSERT(copy_subsub);
 563                 VERIFY0(dmu_buf_hold(bpo->bpo_os, subobj,
 564                     0, FTAG, &bps, 0));
 565
 566                 /*
 567                  * Make sure that we are not asking dmu_write()
 568                  * to write more data than we have in our buffer.
 569                  */
 570                 VERIFY3U(bps->db_size, >=, numbps * sizeof (blkptr_t));
 571                 dmu_write(bpo->bpo_os, bpo->bpo_object,
 572                     bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t),
 573                     numbps * sizeof (blkptr_t),
 574                     bps->db_data, tx);
 575                 dmu_buf_rele(bps, FTAG);
 576                 bpo->bpo_phys->bpo_num_blkptrs += numbps;
 577
 578                 bpobj_close(&subbpo);
 579                 VERIFY0(dmu_object_free(bpo->bpo_os, subobj, tx));
 580         } else {
 581                 bpobj_close(&subbpo);
 582                 if (bpo->bpo_phys->bpo_subobjs == 0) {
 583                         bpo->bpo_phys->bpo_subobjs =
 584                             dmu_object_alloc(bpo->bpo_os,
 585                             DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
 586                             DMU_OT_NONE, 0, tx);
 587                 }
 588
 589                 dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
 590                     bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
 591                     sizeof (subobj), &subobj, tx);
 592                 bpo->bpo_phys->bpo_num_subobjs++;
 593         }
 594
 595         bpo->bpo_phys->bpo_bytes += used;
 596         bpo->bpo_phys->bpo_comp += comp;
 597         bpo->bpo_phys->bpo_uncomp += uncomp;
 598         mutex_exit(&bpo->bpo_lock);
 599
 600 }
 601
 602 void
 603 bpobj_enqueue(bpobj_t *bpo, const blkptr_t *bp, dmu_tx_t *tx)
 604 {
 605         blkptr_t stored_bp = *bp;
 606         uint64_t offset;
 607         int blkoff;
 608         blkptr_t *bparray;
 609
 610         ASSERT(bpobj_is_open(bpo));
 611         ASSERT(!BP_IS_HOLE(bp));
 612         ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
 613
 614         if (BP_IS_EMBEDDED(bp)) {
 615                 /*
 616                  * The bpobj will compress better without the payload.
 617                  *
 618                  * Note that we store EMBEDDED bp's because they have an
 619                  * uncompressed size, which must be accounted for.  An
 620                  * alternative would be to add their size to bpo_uncomp
 621                  * without storing the bp, but that would create additional
 622                  * complications: bpo_uncomp would be inconsistent with the
 623                  * set of BP's stored, and bpobj_iterate() wouldn't visit
 624                  * all the space accounted for in the bpobj.
 625                  */
 626                 bzero(&stored_bp, sizeof (stored_bp));
 627                 stored_bp.blk_prop = bp->blk_prop;
 628                 stored_bp.blk_birth = bp->blk_birth;
 629         } else if (!BP_GET_DEDUP(bp)) {
 630                 /* The bpobj will compress better without the checksum */
 631                 bzero(&stored_bp.blk_cksum, sizeof (stored_bp.blk_cksum));
 632         }
 633
 634         /* We never need the fill count. */
 635         stored_bp.blk_fill = 0;
 636
 637         mutex_enter(&bpo->bpo_lock);
 638
 639         offset = bpo->bpo_phys->bpo_num_blkptrs * sizeof (stored_bp);
 640         blkoff = P2PHASE(bpo->bpo_phys->bpo_num_blkptrs, bpo->bpo_epb);
 641
 642         if (bpo->bpo_cached_dbuf == NULL ||
 643             offset < bpo->bpo_cached_dbuf->db_offset ||
 644             offset >= bpo->bpo_cached_dbuf->db_offset +
 645             bpo->bpo_cached_dbuf->db_size) {
 646                 if (bpo->bpo_cached_dbuf)
 647                         dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
 648                 VERIFY3U(0, ==, dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
 649                     offset, bpo, &bpo->bpo_cached_dbuf, 0));
 650         }
 651
 652         dmu_buf_will_dirty(bpo->bpo_cached_dbuf, tx);
 653         bparray = bpo->bpo_cached_dbuf->db_data;
 654         bparray[blkoff] = stored_bp;
 655
 656         dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
 657         bpo->bpo_phys->bpo_num_blkptrs++;
 658         bpo->bpo_phys->bpo_bytes +=
 659             bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
 660         if (bpo->bpo_havecomp) {
 661                 bpo->bpo_phys->bpo_comp += BP_GET_PSIZE(bp);
 662                 bpo->bpo_phys->bpo_uncomp += BP_GET_UCSIZE(bp);
 663         }
 664         mutex_exit(&bpo->bpo_lock);
 665 }
 666
 667 struct space_range_arg {
 668         spa_t *spa;
 669         uint64_t mintxg;
 670         uint64_t maxtxg;
 671         uint64_t used;
 672         uint64_t comp;
 673         uint64_t uncomp;
 674 };
 675
 676 /* ARGSUSED */
 677 static int
 678 space_range_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
 679 {
 680         struct space_range_arg *sra = arg;
 681
 682         if (bp->blk_birth > sra->mintxg && bp->blk_birth <= sra->maxtxg) {
 683                 if (dsl_pool_sync_context(spa_get_dsl(sra->spa)))
 684                         sra->used += bp_get_dsize_sync(sra->spa, bp);
 685                 else
 686                         sra->used += bp_get_dsize(sra->spa, bp);
 687                 sra->comp += BP_GET_PSIZE(bp);
 688                 sra->uncomp += BP_GET_UCSIZE(bp);
 689         }
 690         return (0);
 691 }
 692
 693 int
 694 bpobj_space(bpobj_t *bpo, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
 695 {
 696         ASSERT(bpobj_is_open(bpo));
 697         mutex_enter(&bpo->bpo_lock);
 698
 699         *usedp = bpo->bpo_phys->bpo_bytes;
 700         if (bpo->bpo_havecomp) {
 701                 *compp = bpo->bpo_phys->bpo_comp;
 702                 *uncompp = bpo->bpo_phys->bpo_uncomp;
 703                 mutex_exit(&bpo->bpo_lock);
 704                 return (0);
 705         } else {
 706                 mutex_exit(&bpo->bpo_lock);
 707                 return (bpobj_space_range(bpo, 0, UINT64_MAX,
 708                     usedp, compp, uncompp));
 709         }
 710 }
 711
 712 /*
 713  * Return the amount of space in the bpobj which is:
 714  * mintxg < blk_birth <= maxtxg
 715  */
 716 int
 717 bpobj_space_range(bpobj_t *bpo, uint64_t mintxg, uint64_t maxtxg,
 718     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
 719 {
 720         struct space_range_arg sra = { 0 };
 721         int err;
 722
 723         ASSERT(bpobj_is_open(bpo));
 724
 725         /*
 726          * As an optimization, if they want the whole txg range, just
 727          * get bpo_bytes rather than iterating over the bps.
 728          */
 729         if (mintxg < TXG_INITIAL && maxtxg == UINT64_MAX && bpo->bpo_havecomp)
 730                 return (bpobj_space(bpo, usedp, compp, uncompp));
 731
 732         sra.spa = dmu_objset_spa(bpo->bpo_os);
 733         sra.mintxg = mintxg;
 734         sra.maxtxg = maxtxg;
 735
 736         err = bpobj_iterate_nofree(bpo, space_range_cb, &sra, NULL);
 737         *usedp = sra.used;
 738         *compp = sra.comp;
 739         *uncompp = sra.uncomp;
 740         return (err);
 741 }