module/zfs/dsl_dir.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  */
  24
  25 #include <sys/dmu.h>
  26 #include <sys/dmu_objset.h>
  27 #include <sys/dmu_tx.h>
  28 #include <sys/dsl_dataset.h>
  29 #include <sys/dsl_dir.h>
  30 #include <sys/dsl_prop.h>
  31 #include <sys/dsl_synctask.h>
  32 #include <sys/dsl_deleg.h>
  33 #include <sys/spa.h>
  34 #include <sys/metaslab.h>
  35 #include <sys/zap.h>
  36 #include <sys/zio.h>
  37 #include <sys/arc.h>
  38 #include <sys/sunddi.h>
  39 #include "zfs_namecheck.h"
  40
  41 static uint64_t dsl_dir_space_towrite(dsl_dir_t *dd);
  42 static void dsl_dir_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx);
  43
  44
  45 /* ARGSUSED */
  46 static void
  47 dsl_dir_evict(dmu_buf_t *db, void *arg)
  48 {
  49         dsl_dir_t *dd = arg;
  50         ASSERTV(dsl_pool_t *dp = dd->dd_pool;)
  51         int t;
  52
  53         for (t = 0; t < TXG_SIZE; t++) {
  54                 ASSERT(!txg_list_member(&dp->dp_dirty_dirs, dd, t));
  55                 ASSERT(dd->dd_tempreserved[t] == 0);
  56                 ASSERT(dd->dd_space_towrite[t] == 0);
  57         }
  58
  59         if (dd->dd_parent)
  60                 dsl_dir_close(dd->dd_parent, dd);
  61
  62         spa_close(dd->dd_pool->dp_spa, dd);
  63
  64         /*
  65          * The props callback list should have been cleaned up by
  66          * objset_evict().
  67          */
  68         list_destroy(&dd->dd_prop_cbs);
  69         mutex_destroy(&dd->dd_lock);
  70         kmem_free(dd, sizeof (dsl_dir_t));
  71 }
  72
  73 int
  74 dsl_dir_open_obj(dsl_pool_t *dp, uint64_t ddobj,
  75     const char *tail, void *tag, dsl_dir_t **ddp)
  76 {
  77         dmu_buf_t *dbuf;
  78         dsl_dir_t *dd;
  79         int err;
  80
  81         ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
  82             dsl_pool_sync_context(dp));
  83
  84         err = dmu_bonus_hold(dp->dp_meta_objset, ddobj, tag, &dbuf);
  85         if (err)
  86                 return (err);
  87         dd = dmu_buf_get_user(dbuf);
  88 #ifdef ZFS_DEBUG
  89         {
  90                 dmu_object_info_t doi;
  91                 dmu_object_info_from_db(dbuf, &doi);
  92                 ASSERT3U(doi.doi_type, ==, DMU_OT_DSL_DIR);
  93                 ASSERT3U(doi.doi_bonus_size, >=, sizeof (dsl_dir_phys_t));
  94         }
  95 #endif
  96         if (dd == NULL) {
  97                 dsl_dir_t *winner;
  98
  99                 dd = kmem_zalloc(sizeof (dsl_dir_t), KM_PUSHPAGE);
 100                 dd->dd_object = ddobj;
 101                 dd->dd_dbuf = dbuf;
 102                 dd->dd_pool = dp;
 103                 dd->dd_phys = dbuf->db_data;
 104                 mutex_init(&dd->dd_lock, NULL, MUTEX_DEFAULT, NULL);
 105
 106                 list_create(&dd->dd_prop_cbs, sizeof (dsl_prop_cb_record_t),
 107                     offsetof(dsl_prop_cb_record_t, cbr_node));
 108
 109                 dsl_dir_snap_cmtime_update(dd);
 110
 111                 if (dd->dd_phys->dd_parent_obj) {
 112                         err = dsl_dir_open_obj(dp, dd->dd_phys->dd_parent_obj,
 113                             NULL, dd, &dd->dd_parent);
 114                         if (err)
 115                                 goto errout;
 116                         if (tail) {
 117 #ifdef ZFS_DEBUG
 118                                 uint64_t foundobj;
 119
 120                                 err = zap_lookup(dp->dp_meta_objset,
 121                                     dd->dd_parent->dd_phys->dd_child_dir_zapobj,
 122                                     tail, sizeof (foundobj), 1, &foundobj);
 123                                 ASSERT(err || foundobj == ddobj);
 124 #endif
 125                                 (void) strcpy(dd->dd_myname, tail);
 126                         } else {
 127                                 err = zap_value_search(dp->dp_meta_objset,
 128                                     dd->dd_parent->dd_phys->dd_child_dir_zapobj,
 129                                     ddobj, 0, dd->dd_myname);
 130                         }
 131                         if (err)
 132                                 goto errout;
 133                 } else {
 134                         (void) strcpy(dd->dd_myname, spa_name(dp->dp_spa));
 135                 }
 136
 137                 if (dsl_dir_is_clone(dd)) {
 138                         dmu_buf_t *origin_bonus;
 139                         dsl_dataset_phys_t *origin_phys;
 140
 141                         /*
 142                          * We can't open the origin dataset, because
 143                          * that would require opening this dsl_dir.
 144                          * Just look at its phys directly instead.
 145                          */
 146                         err = dmu_bonus_hold(dp->dp_meta_objset,
 147                             dd->dd_phys->dd_origin_obj, FTAG, &origin_bonus);
 148                         if (err)
 149                                 goto errout;
 150                         origin_phys = origin_bonus->db_data;
 151                         dd->dd_origin_txg =
 152                             origin_phys->ds_creation_txg;
 153                         dmu_buf_rele(origin_bonus, FTAG);
 154                 }
 155
 156                 winner = dmu_buf_set_user_ie(dbuf, dd, &dd->dd_phys,
 157                     dsl_dir_evict);
 158                 if (winner) {
 159                         if (dd->dd_parent)
 160                                 dsl_dir_close(dd->dd_parent, dd);
 161                         mutex_destroy(&dd->dd_lock);
 162                         kmem_free(dd, sizeof (dsl_dir_t));
 163                         dd = winner;
 164                 } else {
 165                         spa_open_ref(dp->dp_spa, dd);
 166                 }
 167         }
 168
 169         /*
 170          * The dsl_dir_t has both open-to-close and instantiate-to-evict
 171          * holds on the spa.  We need the open-to-close holds because
 172          * otherwise the spa_refcnt wouldn't change when we open a
 173          * dir which the spa also has open, so we could incorrectly
 174          * think it was OK to unload/export/destroy the pool.  We need
 175          * the instantiate-to-evict hold because the dsl_dir_t has a
 176          * pointer to the dd_pool, which has a pointer to the spa_t.
 177          */
 178         spa_open_ref(dp->dp_spa, tag);
 179         ASSERT3P(dd->dd_pool, ==, dp);
 180         ASSERT3U(dd->dd_object, ==, ddobj);
 181         ASSERT3P(dd->dd_dbuf, ==, dbuf);
 182         *ddp = dd;
 183         return (0);
 184
 185 errout:
 186         if (dd->dd_parent)
 187                 dsl_dir_close(dd->dd_parent, dd);
 188         mutex_destroy(&dd->dd_lock);
 189         kmem_free(dd, sizeof (dsl_dir_t));
 190         dmu_buf_rele(dbuf, tag);
 191         return (err);
 192
 193 }
 194
 195 void
 196 dsl_dir_close(dsl_dir_t *dd, void *tag)
 197 {
 198         dprintf_dd(dd, "%s\n", "");
 199         spa_close(dd->dd_pool->dp_spa, tag);
 200         dmu_buf_rele(dd->dd_dbuf, tag);
 201 }
 202
 203 /* buf must be long enough (MAXNAMELEN + strlen(MOS_DIR_NAME) + 1 should do) */
 204 void
 205 dsl_dir_name(dsl_dir_t *dd, char *buf)
 206 {
 207         if (dd->dd_parent) {
 208                 dsl_dir_name(dd->dd_parent, buf);
 209                 (void) strcat(buf, "/");
 210         } else {
 211                 buf[0] = '\0';
 212         }
 213         if (!MUTEX_HELD(&dd->dd_lock)) {
 214                 /*
 215                  * recursive mutex so that we can use
 216                  * dprintf_dd() with dd_lock held
 217                  */
 218                 mutex_enter(&dd->dd_lock);
 219                 (void) strcat(buf, dd->dd_myname);
 220                 mutex_exit(&dd->dd_lock);
 221         } else {
 222                 (void) strcat(buf, dd->dd_myname);
 223         }
 224 }
 225
 226 /* Calculate name legnth, avoiding all the strcat calls of dsl_dir_name */
 227 int
 228 dsl_dir_namelen(dsl_dir_t *dd)
 229 {
 230         int result = 0;
 231
 232         if (dd->dd_parent) {
 233                 /* parent's name + 1 for the "/" */
 234                 result = dsl_dir_namelen(dd->dd_parent) + 1;
 235         }
 236
 237         if (!MUTEX_HELD(&dd->dd_lock)) {
 238                 /* see dsl_dir_name */
 239                 mutex_enter(&dd->dd_lock);
 240                 result += strlen(dd->dd_myname);
 241                 mutex_exit(&dd->dd_lock);
 242         } else {
 243                 result += strlen(dd->dd_myname);
 244         }
 245
 246         return (result);
 247 }
 248
 249 static int
 250 getcomponent(const char *path, char *component, const char **nextp)
 251 {
 252         char *p;
 253         if ((path == NULL) || (path[0] == '\0'))
 254                 return (ENOENT);
 255         /* This would be a good place to reserve some namespace... */
 256         p = strpbrk(path, "/@");
 257         if (p && (p[1] == '/' || p[1] == '@')) {
 258                 /* two separators in a row */
 259                 return (EINVAL);
 260         }
 261         if (p == NULL || p == path) {
 262                 /*
 263                  * if the first thing is an @ or /, it had better be an
 264                  * @ and it had better not have any more ats or slashes,
 265                  * and it had better have something after the @.
 266                  */
 267                 if (p != NULL &&
 268                     (p[0] != '@' || strpbrk(path+1, "/@") || p[1] == '\0'))
 269                         return (EINVAL);
 270                 if (strlen(path) >= MAXNAMELEN)
 271                         return (ENAMETOOLONG);
 272                 (void) strcpy(component, path);
 273                 p = NULL;
 274         } else if (p[0] == '/') {
 275                 if (p-path >= MAXNAMELEN)
 276                         return (ENAMETOOLONG);
 277                 (void) strncpy(component, path, p - path);
 278                 component[p-path] = '\0';
 279                 p++;
 280         } else if (p[0] == '@') {
 281                 /*
 282                  * if the next separator is an @, there better not be
 283                  * any more slashes.
 284                  */
 285                 if (strchr(path, '/'))
 286                         return (EINVAL);
 287                 if (p-path >= MAXNAMELEN)
 288                         return (ENAMETOOLONG);
 289                 (void) strncpy(component, path, p - path);
 290                 component[p-path] = '\0';
 291         } else {
 292                 ASSERT(!"invalid p");
 293         }
 294         *nextp = p;
 295         return (0);
 296 }
 297
 298 /*
 299  * same as dsl_open_dir, ignore the first component of name and use the
 300  * spa instead
 301  */
 302 int
 303 dsl_dir_open_spa(spa_t *spa, const char *name, void *tag,
 304     dsl_dir_t **ddp, const char **tailp)
 305 {
 306         char *buf;
 307         const char *next, *nextnext = NULL;
 308         int err;
 309         dsl_dir_t *dd;
 310         dsl_pool_t *dp;
 311         uint64_t ddobj;
 312         int openedspa = FALSE;
 313
 314         dprintf("%s\n", name);
 315
 316         buf = kmem_alloc(MAXNAMELEN, KM_SLEEP);
 317         err = getcomponent(name, buf, &next);
 318         if (err)
 319                 goto error;
 320         if (spa == NULL) {
 321                 err = spa_open(buf, &spa, FTAG);
 322                 if (err) {
 323                         dprintf("spa_open(%s) failed\n", buf);
 324                         goto error;
 325                 }
 326                 openedspa = TRUE;
 327
 328                 /* XXX this assertion belongs in spa_open */
 329                 ASSERT(!dsl_pool_sync_context(spa_get_dsl(spa)));
 330         }
 331
 332         dp = spa_get_dsl(spa);
 333
 334         rw_enter(&dp->dp_config_rwlock, RW_READER);
 335         err = dsl_dir_open_obj(dp, dp->dp_root_dir_obj, NULL, tag, &dd);
 336         if (err) {
 337                 rw_exit(&dp->dp_config_rwlock);
 338                 if (openedspa)
 339                         spa_close(spa, FTAG);
 340                 goto error;
 341         }
 342
 343         while (next != NULL) {
 344                 dsl_dir_t *child_ds;
 345                 err = getcomponent(next, buf, &nextnext);
 346                 if (err)
 347                         break;
 348                 ASSERT(next[0] != '\0');
 349                 if (next[0] == '@')
 350                         break;
 351                 dprintf("looking up %s in obj%lld\n",
 352                     buf, dd->dd_phys->dd_child_dir_zapobj);
 353
 354                 err = zap_lookup(dp->dp_meta_objset,
 355                     dd->dd_phys->dd_child_dir_zapobj,
 356                     buf, sizeof (ddobj), 1, &ddobj);
 357                 if (err) {
 358                         if (err == ENOENT)
 359                                 err = 0;
 360                         break;
 361                 }
 362
 363                 err = dsl_dir_open_obj(dp, ddobj, buf, tag, &child_ds);
 364                 if (err)
 365                         break;
 366                 dsl_dir_close(dd, tag);
 367                 dd = child_ds;
 368                 next = nextnext;
 369         }
 370         rw_exit(&dp->dp_config_rwlock);
 371
 372         if (err) {
 373                 dsl_dir_close(dd, tag);
 374                 if (openedspa)
 375                         spa_close(spa, FTAG);
 376                 goto error;
 377         }
 378
 379         /*
 380          * It's an error if there's more than one component left, or
 381          * tailp==NULL and there's any component left.
 382          */
 383         if (next != NULL &&
 384             (tailp == NULL || (nextnext && nextnext[0] != '\0'))) {
 385                 /* bad path name */
 386                 dsl_dir_close(dd, tag);
 387                 dprintf("next=%p (%s) tail=%p\n", next, next?next:"", tailp);
 388                 err = ENOENT;
 389         }
 390         if (tailp)
 391                 *tailp = next;
 392         if (openedspa)
 393                 spa_close(spa, FTAG);
 394         *ddp = dd;
 395 error:
 396         kmem_free(buf, MAXNAMELEN);
 397         return (err);
 398 }
 399
 400 /*
 401  * Return the dsl_dir_t, and possibly the last component which couldn't
 402  * be found in *tail.  Return NULL if the path is bogus, or if
 403  * tail==NULL and we couldn't parse the whole name.  (*tail)[0] == '@'
 404  * means that the last component is a snapshot.
 405  */
 406 int
 407 dsl_dir_open(const char *name, void *tag, dsl_dir_t **ddp, const char **tailp)
 408 {
 409         return (dsl_dir_open_spa(NULL, name, tag, ddp, tailp));
 410 }
 411
 412 uint64_t
 413 dsl_dir_create_sync(dsl_pool_t *dp, dsl_dir_t *pds, const char *name,
 414     dmu_tx_t *tx)
 415 {
 416         objset_t *mos = dp->dp_meta_objset;
 417         uint64_t ddobj;
 418         dsl_dir_phys_t *ddphys;
 419         dmu_buf_t *dbuf;
 420
 421         ddobj = dmu_object_alloc(mos, DMU_OT_DSL_DIR, 0,
 422             DMU_OT_DSL_DIR, sizeof (dsl_dir_phys_t), tx);
 423         if (pds) {
 424                 VERIFY(0 == zap_add(mos, pds->dd_phys->dd_child_dir_zapobj,
 425                     name, sizeof (uint64_t), 1, &ddobj, tx));
 426         } else {
 427                 /* it's the root dir */
 428                 VERIFY(0 == zap_add(mos, DMU_POOL_DIRECTORY_OBJECT,
 429                     DMU_POOL_ROOT_DATASET, sizeof (uint64_t), 1, &ddobj, tx));
 430         }
 431         VERIFY(0 == dmu_bonus_hold(mos, ddobj, FTAG, &dbuf));
 432         dmu_buf_will_dirty(dbuf, tx);
 433         ddphys = dbuf->db_data;
 434
 435         ddphys->dd_creation_time = gethrestime_sec();
 436         if (pds)
 437                 ddphys->dd_parent_obj = pds->dd_object;
 438         ddphys->dd_props_zapobj = zap_create(mos,
 439             DMU_OT_DSL_PROPS, DMU_OT_NONE, 0, tx);
 440         ddphys->dd_child_dir_zapobj = zap_create(mos,
 441             DMU_OT_DSL_DIR_CHILD_MAP, DMU_OT_NONE, 0, tx);
 442         if (spa_version(dp->dp_spa) >= SPA_VERSION_USED_BREAKDOWN)
 443                 ddphys->dd_flags |= DD_FLAG_USED_BREAKDOWN;
 444         dmu_buf_rele(dbuf, FTAG);
 445
 446         return (ddobj);
 447 }
 448
 449 /* ARGSUSED */
 450 int
 451 dsl_dir_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
 452 {
 453         dsl_dataset_t *ds = arg1;
 454         dsl_dir_t *dd = ds->ds_dir;
 455         dsl_pool_t *dp = dd->dd_pool;
 456         objset_t *mos = dp->dp_meta_objset;
 457         int err;
 458         uint64_t count;
 459
 460         /*
 461          * There should be exactly two holds, both from
 462          * dsl_dataset_destroy: one on the dd directory, and one on its
 463          * head ds.  If there are more holds, then a concurrent thread is
 464          * performing a lookup inside this dir while we're trying to destroy
 465          * it.  To minimize this possibility, we perform this check only
 466          * in syncing context and fail the operation if we encounter
 467          * additional holds.  The dp_config_rwlock ensures that nobody else
 468          * opens it after we check.
 469          */
 470         if (dmu_tx_is_syncing(tx) && dmu_buf_refcount(dd->dd_dbuf) > 2)
 471                 return (EBUSY);
 472
 473         err = zap_count(mos, dd->dd_phys->dd_child_dir_zapobj, &count);
 474         if (err)
 475                 return (err);
 476         if (count != 0)
 477                 return (EEXIST);
 478
 479         return (0);
 480 }
 481
 482 void
 483 dsl_dir_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
 484 {
 485         dsl_dataset_t *ds = arg1;
 486         dsl_dir_t *dd = ds->ds_dir;
 487         objset_t *mos = dd->dd_pool->dp_meta_objset;
 488         dsl_prop_setarg_t psa;
 489         uint64_t value = 0;
 490         uint64_t obj;
 491         dd_used_t t;
 492
 493         ASSERT(RW_WRITE_HELD(&dd->dd_pool->dp_config_rwlock));
 494         ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
 495
 496         /* Remove our reservation. */
 497         dsl_prop_setarg_init_uint64(&psa, "reservation",
 498             (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
 499             &value);
 500         psa.psa_effective_value = 0;    /* predict default value */
 501
 502         dsl_dir_set_reservation_sync(ds, &psa, tx);
 503
 504         ASSERT3U(dd->dd_phys->dd_used_bytes, ==, 0);
 505         ASSERT3U(dd->dd_phys->dd_reserved, ==, 0);
 506         for (t = 0; t < DD_USED_NUM; t++)
 507                 ASSERT3U(dd->dd_phys->dd_used_breakdown[t], ==, 0);
 508
 509         VERIFY(0 == zap_destroy(mos, dd->dd_phys->dd_child_dir_zapobj, tx));
 510         VERIFY(0 == zap_destroy(mos, dd->dd_phys->dd_props_zapobj, tx));
 511         VERIFY(0 == dsl_deleg_destroy(mos, dd->dd_phys->dd_deleg_zapobj, tx));
 512         VERIFY(0 == zap_remove(mos,
 513             dd->dd_parent->dd_phys->dd_child_dir_zapobj, dd->dd_myname, tx));
 514
 515         obj = dd->dd_object;
 516         dsl_dir_close(dd, tag);
 517         VERIFY(0 == dmu_object_free(mos, obj, tx));
 518 }
 519
 520 boolean_t
 521 dsl_dir_is_clone(dsl_dir_t *dd)
 522 {
 523         return (dd->dd_phys->dd_origin_obj &&
 524             (dd->dd_pool->dp_origin_snap == NULL ||
 525             dd->dd_phys->dd_origin_obj !=
 526             dd->dd_pool->dp_origin_snap->ds_object));
 527 }
 528
 529 void
 530 dsl_dir_stats(dsl_dir_t *dd, nvlist_t *nv)
 531 {
 532         mutex_enter(&dd->dd_lock);
 533         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
 534             dd->dd_phys->dd_used_bytes);
 535         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_QUOTA, dd->dd_phys->dd_quota);
 536         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_RESERVATION,
 537             dd->dd_phys->dd_reserved);
 538         dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
 539             dd->dd_phys->dd_compressed_bytes == 0 ? 100 :
 540             (dd->dd_phys->dd_uncompressed_bytes * 100 /
 541             dd->dd_phys->dd_compressed_bytes));
 542         if (dd->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
 543                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDSNAP,
 544                     dd->dd_phys->dd_used_breakdown[DD_USED_SNAP]);
 545                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDDS,
 546                     dd->dd_phys->dd_used_breakdown[DD_USED_HEAD]);
 547                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDREFRESERV,
 548                     dd->dd_phys->dd_used_breakdown[DD_USED_REFRSRV]);
 549                 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USEDCHILD,
 550                     dd->dd_phys->dd_used_breakdown[DD_USED_CHILD] +
 551                     dd->dd_phys->dd_used_breakdown[DD_USED_CHILD_RSRV]);
 552         }
 553         mutex_exit(&dd->dd_lock);
 554
 555         rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
 556         if (dsl_dir_is_clone(dd)) {
 557                 dsl_dataset_t *ds;
 558                 char buf[MAXNAMELEN];
 559
 560                 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
 561                     dd->dd_phys->dd_origin_obj, FTAG, &ds));
 562                 dsl_dataset_name(ds, buf);
 563                 dsl_dataset_rele(ds, FTAG);
 564                 dsl_prop_nvlist_add_string(nv, ZFS_PROP_ORIGIN, buf);
 565         }
 566         rw_exit(&dd->dd_pool->dp_config_rwlock);
 567 }
 568
 569 void
 570 dsl_dir_dirty(dsl_dir_t *dd, dmu_tx_t *tx)
 571 {
 572         dsl_pool_t *dp = dd->dd_pool;
 573
 574         ASSERT(dd->dd_phys);
 575
 576         if (txg_list_add(&dp->dp_dirty_dirs, dd, tx->tx_txg) == 0) {
 577                 /* up the hold count until we can be written out */
 578                 dmu_buf_add_ref(dd->dd_dbuf, dd);
 579         }
 580 }
 581
 582 static int64_t
 583 parent_delta(dsl_dir_t *dd, uint64_t used, int64_t delta)
 584 {
 585         uint64_t old_accounted = MAX(used, dd->dd_phys->dd_reserved);
 586         uint64_t new_accounted = MAX(used + delta, dd->dd_phys->dd_reserved);
 587         return (new_accounted - old_accounted);
 588 }
 589
 590 void
 591 dsl_dir_sync(dsl_dir_t *dd, dmu_tx_t *tx)
 592 {
 593         ASSERT(dmu_tx_is_syncing(tx));
 594
 595         dmu_buf_will_dirty(dd->dd_dbuf, tx);
 596
 597         mutex_enter(&dd->dd_lock);
 598         ASSERT3U(dd->dd_tempreserved[tx->tx_txg&TXG_MASK], ==, 0);
 599         dprintf_dd(dd, "txg=%llu towrite=%lluK\n", tx->tx_txg,
 600             dd->dd_space_towrite[tx->tx_txg&TXG_MASK] / 1024);
 601         dd->dd_space_towrite[tx->tx_txg&TXG_MASK] = 0;
 602         mutex_exit(&dd->dd_lock);
 603
 604         /* release the hold from dsl_dir_dirty */
 605         dmu_buf_rele(dd->dd_dbuf, dd);
 606 }
 607
 608 static uint64_t
 609 dsl_dir_space_towrite(dsl_dir_t *dd)
 610 {
 611         uint64_t space = 0;
 612         int i;
 613
 614         ASSERT(MUTEX_HELD(&dd->dd_lock));
 615
 616         for (i = 0; i < TXG_SIZE; i++) {
 617                 space += dd->dd_space_towrite[i&TXG_MASK];
 618                 ASSERT3U(dd->dd_space_towrite[i&TXG_MASK], >=, 0);
 619         }
 620         return (space);
 621 }
 622
 623 /*
 624  * How much space would dd have available if ancestor had delta applied
 625  * to it?  If ondiskonly is set, we're only interested in what's
 626  * on-disk, not estimated pending changes.
 627  */
 628 uint64_t
 629 dsl_dir_space_available(dsl_dir_t *dd,
 630     dsl_dir_t *ancestor, int64_t delta, int ondiskonly)
 631 {
 632         uint64_t parentspace, myspace, quota, used;
 633
 634         /*
 635          * If there are no restrictions otherwise, assume we have
 636          * unlimited space available.
 637          */
 638         quota = UINT64_MAX;
 639         parentspace = UINT64_MAX;
 640
 641         if (dd->dd_parent != NULL) {
 642                 parentspace = dsl_dir_space_available(dd->dd_parent,
 643                     ancestor, delta, ondiskonly);
 644         }
 645
 646         mutex_enter(&dd->dd_lock);
 647         if (dd->dd_phys->dd_quota != 0)
 648                 quota = dd->dd_phys->dd_quota;
 649         used = dd->dd_phys->dd_used_bytes;
 650         if (!ondiskonly)
 651                 used += dsl_dir_space_towrite(dd);
 652
 653         if (dd->dd_parent == NULL) {
 654                 uint64_t poolsize = dsl_pool_adjustedsize(dd->dd_pool, FALSE);
 655                 quota = MIN(quota, poolsize);
 656         }
 657
 658         if (dd->dd_phys->dd_reserved > used && parentspace != UINT64_MAX) {
 659                 /*
 660                  * We have some space reserved, in addition to what our
 661                  * parent gave us.
 662                  */
 663                 parentspace += dd->dd_phys->dd_reserved - used;
 664         }
 665
 666         if (dd == ancestor) {
 667                 ASSERT(delta <= 0);
 668                 ASSERT(used >= -delta);
 669                 used += delta;
 670                 if (parentspace != UINT64_MAX)
 671                         parentspace -= delta;
 672         }
 673
 674         if (used > quota) {
 675                 /* over quota */
 676                 myspace = 0;
 677         } else {
 678                 /*
 679                  * the lesser of the space provided by our parent and
 680                  * the space left in our quota
 681                  */
 682                 myspace = MIN(parentspace, quota - used);
 683         }
 684
 685         mutex_exit(&dd->dd_lock);
 686
 687         return (myspace);
 688 }
 689
 690 struct tempreserve {
 691         list_node_t tr_node;
 692         dsl_pool_t *tr_dp;
 693         dsl_dir_t *tr_ds;
 694         uint64_t tr_size;
 695 };
 696
 697 static int
 698 dsl_dir_tempreserve_impl(dsl_dir_t *dd, uint64_t asize, boolean_t netfree,
 699     boolean_t ignorequota, boolean_t checkrefquota, list_t *tr_list,
 700     dmu_tx_t *tx, boolean_t first)
 701 {
 702         uint64_t txg = tx->tx_txg;
 703         uint64_t est_inflight, used_on_disk, quota, parent_rsrv;
 704         uint64_t deferred = 0;
 705         struct tempreserve *tr;
 706         int retval = EDQUOT;
 707         int txgidx = txg & TXG_MASK;
 708         int i;
 709         uint64_t ref_rsrv = 0;
 710
 711         ASSERT3U(txg, !=, 0);
 712         ASSERT3S(asize, >, 0);
 713
 714         mutex_enter(&dd->dd_lock);
 715
 716         /*
 717          * Check against the dsl_dir's quota.  We don't add in the delta
 718          * when checking for over-quota because they get one free hit.
 719          */
 720         est_inflight = dsl_dir_space_towrite(dd);
 721         for (i = 0; i < TXG_SIZE; i++)
 722                 est_inflight += dd->dd_tempreserved[i];
 723         used_on_disk = dd->dd_phys->dd_used_bytes;
 724
 725         /*
 726          * On the first iteration, fetch the dataset's used-on-disk and
 727          * refreservation values. Also, if checkrefquota is set, test if
 728          * allocating this space would exceed the dataset's refquota.
 729          */
 730         if (first && tx->tx_objset) {
 731                 int error;
 732                 dsl_dataset_t *ds = tx->tx_objset->os_dsl_dataset;
 733
 734                 error = dsl_dataset_check_quota(ds, checkrefquota,
 735                     asize, est_inflight, &used_on_disk, &ref_rsrv);
 736                 if (error) {
 737                         mutex_exit(&dd->dd_lock);
 738                         return (error);
 739                 }
 740         }
 741
 742         /*
 743          * If this transaction will result in a net free of space,
 744          * we want to let it through.
 745          */
 746         if (ignorequota || netfree || dd->dd_phys->dd_quota == 0)
 747                 quota = UINT64_MAX;
 748         else
 749                 quota = dd->dd_phys->dd_quota;
 750
 751         /*
 752          * Adjust the quota against the actual pool size at the root
 753          * minus any outstanding deferred frees.
 754          * To ensure that it's possible to remove files from a full
 755          * pool without inducing transient overcommits, we throttle
 756          * netfree transactions against a quota that is slightly larger,
 757          * but still within the pool's allocation slop.  In cases where
 758          * we're very close to full, this will allow a steady trickle of
 759          * removes to get through.
 760          */
 761         if (dd->dd_parent == NULL) {
 762                 spa_t *spa = dd->dd_pool->dp_spa;
 763                 uint64_t poolsize = dsl_pool_adjustedsize(dd->dd_pool, netfree);
 764                 deferred = metaslab_class_get_deferred(spa_normal_class(spa));
 765                 if (poolsize - deferred < quota) {
 766                         quota = poolsize - deferred;
 767                         retval = ENOSPC;
 768                 }
 769         }
 770
 771         /*
 772          * If they are requesting more space, and our current estimate
 773          * is over quota, they get to try again unless the actual
 774          * on-disk is over quota and there are no pending changes (which
 775          * may free up space for us).
 776          */
 777         if (used_on_disk + est_inflight >= quota) {
 778                 if (est_inflight > 0 || used_on_disk < quota ||
 779                     (retval == ENOSPC && used_on_disk < quota + deferred))
 780                         retval = ERESTART;
 781                 dprintf_dd(dd, "failing: used=%lluK inflight = %lluK "
 782                     "quota=%lluK tr=%lluK err=%d\n",
 783                     used_on_disk>>10, est_inflight>>10,
 784                     quota>>10, asize>>10, retval);
 785                 mutex_exit(&dd->dd_lock);
 786                 return (retval);
 787         }
 788
 789         /* We need to up our estimated delta before dropping dd_lock */
 790         dd->dd_tempreserved[txgidx] += asize;
 791
 792         parent_rsrv = parent_delta(dd, used_on_disk + est_inflight,
 793             asize - ref_rsrv);
 794         mutex_exit(&dd->dd_lock);
 795
 796         tr = kmem_zalloc(sizeof (struct tempreserve), KM_PUSHPAGE);
 797         tr->tr_ds = dd;
 798         tr->tr_size = asize;
 799         list_insert_tail(tr_list, tr);
 800
 801         /* see if it's OK with our parent */
 802         if (dd->dd_parent && parent_rsrv) {
 803                 boolean_t ismos = (dd->dd_phys->dd_head_dataset_obj == 0);
 804
 805                 return (dsl_dir_tempreserve_impl(dd->dd_parent,
 806                     parent_rsrv, netfree, ismos, TRUE, tr_list, tx, FALSE));
 807         } else {
 808                 return (0);
 809         }
 810 }
 811
 812 /*
 813  * Reserve space in this dsl_dir, to be used in this tx's txg.
 814  * After the space has been dirtied (and dsl_dir_willuse_space()
 815  * has been called), the reservation should be canceled, using
 816  * dsl_dir_tempreserve_clear().
 817  */
 818 int
 819 dsl_dir_tempreserve_space(dsl_dir_t *dd, uint64_t lsize, uint64_t asize,
 820     uint64_t fsize, uint64_t usize, void **tr_cookiep, dmu_tx_t *tx)
 821 {
 822         int err;
 823         list_t *tr_list;
 824
 825         if (asize == 0) {
 826                 *tr_cookiep = NULL;
 827                 return (0);
 828         }
 829
 830         tr_list = kmem_alloc(sizeof (list_t), KM_PUSHPAGE);
 831         list_create(tr_list, sizeof (struct tempreserve),
 832             offsetof(struct tempreserve, tr_node));
 833         ASSERT3S(asize, >, 0);
 834         ASSERT3S(fsize, >=, 0);
 835
 836         err = arc_tempreserve_space(lsize, tx->tx_txg);
 837         if (err == 0) {
 838                 struct tempreserve *tr;
 839
 840                 tr = kmem_zalloc(sizeof (struct tempreserve), KM_PUSHPAGE);
 841                 tr->tr_size = lsize;
 842                 list_insert_tail(tr_list, tr);
 843
 844                 err = dsl_pool_tempreserve_space(dd->dd_pool, asize, tx);
 845         } else {
 846                 if (err == EAGAIN) {
 847                         txg_delay(dd->dd_pool, tx->tx_txg, 1);
 848                         err = ERESTART;
 849                 }
 850                 dsl_pool_memory_pressure(dd->dd_pool);
 851         }
 852
 853         if (err == 0) {
 854                 struct tempreserve *tr;
 855
 856                 tr = kmem_zalloc(sizeof (struct tempreserve), KM_PUSHPAGE);
 857                 tr->tr_dp = dd->dd_pool;
 858                 tr->tr_size = asize;
 859                 list_insert_tail(tr_list, tr);
 860
 861                 err = dsl_dir_tempreserve_impl(dd, asize, fsize >= asize,
 862                     FALSE, asize > usize, tr_list, tx, TRUE);
 863         }
 864
 865         if (err)
 866                 dsl_dir_tempreserve_clear(tr_list, tx);
 867         else
 868                 *tr_cookiep = tr_list;
 869
 870         return (err);
 871 }
 872
 873 /*
 874  * Clear a temporary reservation that we previously made with
 875  * dsl_dir_tempreserve_space().
 876  */
 877 void
 878 dsl_dir_tempreserve_clear(void *tr_cookie, dmu_tx_t *tx)
 879 {
 880         int txgidx = tx->tx_txg & TXG_MASK;
 881         list_t *tr_list = tr_cookie;
 882         struct tempreserve *tr;
 883
 884         ASSERT3U(tx->tx_txg, !=, 0);
 885
 886         if (tr_cookie == NULL)
 887                 return;
 888
 889         while ((tr = list_head(tr_list))) {
 890                 if (tr->tr_dp) {
 891                         dsl_pool_tempreserve_clear(tr->tr_dp, tr->tr_size, tx);
 892                 } else if (tr->tr_ds) {
 893                         mutex_enter(&tr->tr_ds->dd_lock);
 894                         ASSERT3U(tr->tr_ds->dd_tempreserved[txgidx], >=,
 895                             tr->tr_size);
 896                         tr->tr_ds->dd_tempreserved[txgidx] -= tr->tr_size;
 897                         mutex_exit(&tr->tr_ds->dd_lock);
 898                 } else {
 899                         arc_tempreserve_clear(tr->tr_size);
 900                 }
 901                 list_remove(tr_list, tr);
 902                 kmem_free(tr, sizeof (struct tempreserve));
 903         }
 904
 905         kmem_free(tr_list, sizeof (list_t));
 906 }
 907
 908 static void
 909 dsl_dir_willuse_space_impl(dsl_dir_t *dd, int64_t space, dmu_tx_t *tx)
 910 {
 911         int64_t parent_space;
 912         uint64_t est_used;
 913
 914         mutex_enter(&dd->dd_lock);
 915         if (space > 0)
 916                 dd->dd_space_towrite[tx->tx_txg & TXG_MASK] += space;
 917
 918         est_used = dsl_dir_space_towrite(dd) + dd->dd_phys->dd_used_bytes;
 919         parent_space = parent_delta(dd, est_used, space);
 920         mutex_exit(&dd->dd_lock);
 921
 922         /* Make sure that we clean up dd_space_to* */
 923         dsl_dir_dirty(dd, tx);
 924
 925         /* XXX this is potentially expensive and unnecessary... */
 926         if (parent_space && dd->dd_parent)
 927                 dsl_dir_willuse_space_impl(dd->dd_parent, parent_space, tx);
 928 }
 929
 930 /*
 931  * Call in open context when we think we're going to write/free space,
 932  * eg. when dirtying data.  Be conservative (ie. OK to write less than
 933  * this or free more than this, but don't write more or free less).
 934  */
 935 void
 936 dsl_dir_willuse_space(dsl_dir_t *dd, int64_t space, dmu_tx_t *tx)
 937 {
 938         dsl_pool_willuse_space(dd->dd_pool, space, tx);
 939         dsl_dir_willuse_space_impl(dd, space, tx);
 940 }
 941
 942 /* call from syncing context when we actually write/free space for this dd */
 943 void
 944 dsl_dir_diduse_space(dsl_dir_t *dd, dd_used_t type,
 945     int64_t used, int64_t compressed, int64_t uncompressed, dmu_tx_t *tx)
 946 {
 947         int64_t accounted_delta;
 948         boolean_t needlock = !MUTEX_HELD(&dd->dd_lock);
 949
 950         ASSERT(dmu_tx_is_syncing(tx));
 951         ASSERT(type < DD_USED_NUM);
 952
 953         dsl_dir_dirty(dd, tx);
 954
 955         if (needlock)
 956                 mutex_enter(&dd->dd_lock);
 957         accounted_delta = parent_delta(dd, dd->dd_phys->dd_used_bytes, used);
 958         ASSERT(used >= 0 || dd->dd_phys->dd_used_bytes >= -used);
 959         ASSERT(compressed >= 0 ||
 960             dd->dd_phys->dd_compressed_bytes >= -compressed);
 961         ASSERT(uncompressed >= 0 ||
 962             dd->dd_phys->dd_uncompressed_bytes >= -uncompressed);
 963         dd->dd_phys->dd_used_bytes += used;
 964         dd->dd_phys->dd_uncompressed_bytes += uncompressed;
 965         dd->dd_phys->dd_compressed_bytes += compressed;
 966
 967         if (dd->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
 968                 ASSERT(used > 0 ||
 969                     dd->dd_phys->dd_used_breakdown[type] >= -used);
 970                 dd->dd_phys->dd_used_breakdown[type] += used;
 971 #ifdef DEBUG
 972                 {
 973                         dd_used_t t;
 974                         uint64_t u = 0;
 975                         for (t = 0; t < DD_USED_NUM; t++)
 976                                 u += dd->dd_phys->dd_used_breakdown[t];
 977                         ASSERT3U(u, ==, dd->dd_phys->dd_used_bytes);
 978                 }
 979 #endif
 980         }
 981         if (needlock)
 982                 mutex_exit(&dd->dd_lock);
 983
 984         if (dd->dd_parent != NULL) {
 985                 dsl_dir_diduse_space(dd->dd_parent, DD_USED_CHILD,
 986                     accounted_delta, compressed, uncompressed, tx);
 987                 dsl_dir_transfer_space(dd->dd_parent,
 988                     used - accounted_delta,
 989                     DD_USED_CHILD_RSRV, DD_USED_CHILD, tx);
 990         }
 991 }
 992
 993 void
 994 dsl_dir_transfer_space(dsl_dir_t *dd, int64_t delta,
 995     dd_used_t oldtype, dd_used_t newtype, dmu_tx_t *tx)
 996 {
 997         boolean_t needlock = !MUTEX_HELD(&dd->dd_lock);
 998
 999         ASSERT(dmu_tx_is_syncing(tx));
1000         ASSERT(oldtype < DD_USED_NUM);
1001         ASSERT(newtype < DD_USED_NUM);
1002
1003         if (delta == 0 || !(dd->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN))
1004                 return;
1005
1006         dsl_dir_dirty(dd, tx);
1007         if (needlock)
1008                 mutex_enter(&dd->dd_lock);
1009         ASSERT(delta > 0 ?
1010             dd->dd_phys->dd_used_breakdown[oldtype] >= delta :
1011             dd->dd_phys->dd_used_breakdown[newtype] >= -delta);
1012         ASSERT(dd->dd_phys->dd_used_bytes >= ABS(delta));
1013         dd->dd_phys->dd_used_breakdown[oldtype] -= delta;
1014         dd->dd_phys->dd_used_breakdown[newtype] += delta;
1015         if (needlock)
1016                 mutex_exit(&dd->dd_lock);
1017 }
1018
1019 static int
1020 dsl_dir_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
1021 {
1022         dsl_dataset_t *ds = arg1;
1023         dsl_dir_t *dd = ds->ds_dir;
1024         dsl_prop_setarg_t *psa = arg2;
1025         int err;
1026         uint64_t towrite;
1027
1028         if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
1029                 return (err);
1030
1031         if (psa->psa_effective_value == 0)
1032                 return (0);
1033
1034         mutex_enter(&dd->dd_lock);
1035         /*
1036          * If we are doing the preliminary check in open context, and
1037          * there are pending changes, then don't fail it, since the
1038          * pending changes could under-estimate the amount of space to be
1039          * freed up.
1040          */
1041         towrite = dsl_dir_space_towrite(dd);
1042         if ((dmu_tx_is_syncing(tx) || towrite == 0) &&
1043             (psa->psa_effective_value < dd->dd_phys->dd_reserved ||
1044             psa->psa_effective_value < dd->dd_phys->dd_used_bytes + towrite)) {
1045                 err = ENOSPC;
1046         }
1047         mutex_exit(&dd->dd_lock);
1048         return (err);
1049 }
1050
1051 extern dsl_syncfunc_t dsl_prop_set_sync;
1052
1053 static void
1054 dsl_dir_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1055 {
1056         dsl_dataset_t *ds = arg1;
1057         dsl_dir_t *dd = ds->ds_dir;
1058         dsl_prop_setarg_t *psa = arg2;
1059         uint64_t effective_value = psa->psa_effective_value;
1060
1061         dsl_prop_set_sync(ds, psa, tx);
1062         DSL_PROP_CHECK_PREDICTION(dd, psa);
1063
1064         dmu_buf_will_dirty(dd->dd_dbuf, tx);
1065
1066         mutex_enter(&dd->dd_lock);
1067         dd->dd_phys->dd_quota = effective_value;
1068         mutex_exit(&dd->dd_lock);
1069 }
1070
1071 int
1072 dsl_dir_set_quota(const char *ddname, zprop_source_t source, uint64_t quota)
1073 {
1074         dsl_dir_t *dd;
1075         dsl_dataset_t *ds;
1076         dsl_prop_setarg_t psa;
1077         int err;
1078
1079         dsl_prop_setarg_init_uint64(&psa, "quota", source, &quota);
1080
1081         err = dsl_dataset_hold(ddname, FTAG, &ds);
1082         if (err)
1083                 return (err);
1084
1085         err = dsl_dir_open(ddname, FTAG, &dd, NULL);
1086         if (err) {
1087                 dsl_dataset_rele(ds, FTAG);
1088                 return (err);
1089         }
1090
1091         ASSERT(ds->ds_dir == dd);
1092
1093         /*
1094          * If someone removes a file, then tries to set the quota, we want to
1095          * make sure the file freeing takes effect.
1096          */
1097         txg_wait_open(dd->dd_pool, 0);
1098
1099         err = dsl_sync_task_do(dd->dd_pool, dsl_dir_set_quota_check,
1100             dsl_dir_set_quota_sync, ds, &psa, 0);
1101
1102         dsl_dir_close(dd, FTAG);
1103         dsl_dataset_rele(ds, FTAG);
1104         return (err);
1105 }
1106
1107 int
1108 dsl_dir_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
1109 {
1110         dsl_dataset_t *ds = arg1;
1111         dsl_dir_t *dd = ds->ds_dir;
1112         dsl_prop_setarg_t *psa = arg2;
1113         uint64_t effective_value;
1114         uint64_t used, avail;
1115         int err;
1116
1117         if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
1118                 return (err);
1119
1120         effective_value = psa->psa_effective_value;
1121
1122         /*
1123          * If we are doing the preliminary check in open context, the
1124          * space estimates may be inaccurate.
1125          */
1126         if (!dmu_tx_is_syncing(tx))
1127                 return (0);
1128
1129         mutex_enter(&dd->dd_lock);
1130         used = dd->dd_phys->dd_used_bytes;
1131         mutex_exit(&dd->dd_lock);
1132
1133         if (dd->dd_parent) {
1134                 avail = dsl_dir_space_available(dd->dd_parent,
1135                     NULL, 0, FALSE);
1136         } else {
1137                 avail = dsl_pool_adjustedsize(dd->dd_pool, B_FALSE) - used;
1138         }
1139
1140         if (MAX(used, effective_value) > MAX(used, dd->dd_phys->dd_reserved)) {
1141                 uint64_t delta = MAX(used, effective_value) -
1142                     MAX(used, dd->dd_phys->dd_reserved);
1143
1144                 if (delta > avail)
1145                         return (ENOSPC);
1146                 if (dd->dd_phys->dd_quota > 0 &&
1147                     effective_value > dd->dd_phys->dd_quota)
1148                         return (ENOSPC);
1149         }
1150
1151         return (0);
1152 }
1153
1154 static void
1155 dsl_dir_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1156 {
1157         dsl_dataset_t *ds = arg1;
1158         dsl_dir_t *dd = ds->ds_dir;
1159         dsl_prop_setarg_t *psa = arg2;
1160         uint64_t effective_value = psa->psa_effective_value;
1161         uint64_t used;
1162         int64_t delta;
1163
1164         dsl_prop_set_sync(ds, psa, tx);
1165         DSL_PROP_CHECK_PREDICTION(dd, psa);
1166
1167         dmu_buf_will_dirty(dd->dd_dbuf, tx);
1168
1169         mutex_enter(&dd->dd_lock);
1170         used = dd->dd_phys->dd_used_bytes;
1171         delta = MAX(used, effective_value) -
1172             MAX(used, dd->dd_phys->dd_reserved);
1173         dd->dd_phys->dd_reserved = effective_value;
1174
1175         if (dd->dd_parent != NULL) {
1176                 /* Roll up this additional usage into our ancestors */
1177                 dsl_dir_diduse_space(dd->dd_parent, DD_USED_CHILD_RSRV,
1178                     delta, 0, 0, tx);
1179         }
1180         mutex_exit(&dd->dd_lock);
1181 }
1182
1183 int
1184 dsl_dir_set_reservation(const char *ddname, zprop_source_t source,
1185     uint64_t reservation)
1186 {
1187         dsl_dir_t *dd;
1188         dsl_dataset_t *ds;
1189         dsl_prop_setarg_t psa;
1190         int err;
1191
1192         dsl_prop_setarg_init_uint64(&psa, "reservation", source, &reservation);
1193
1194         err = dsl_dataset_hold(ddname, FTAG, &ds);
1195         if (err)
1196                 return (err);
1197
1198         err = dsl_dir_open(ddname, FTAG, &dd, NULL);
1199         if (err) {
1200                 dsl_dataset_rele(ds, FTAG);
1201                 return (err);
1202         }
1203
1204         ASSERT(ds->ds_dir == dd);
1205
1206         err = dsl_sync_task_do(dd->dd_pool, dsl_dir_set_reservation_check,
1207             dsl_dir_set_reservation_sync, ds, &psa, 0);
1208
1209         dsl_dir_close(dd, FTAG);
1210         dsl_dataset_rele(ds, FTAG);
1211         return (err);
1212 }
1213
1214 static dsl_dir_t *
1215 closest_common_ancestor(dsl_dir_t *ds1, dsl_dir_t *ds2)
1216 {
1217         for (; ds1; ds1 = ds1->dd_parent) {
1218                 dsl_dir_t *dd;
1219                 for (dd = ds2; dd; dd = dd->dd_parent) {
1220                         if (ds1 == dd)
1221                                 return (dd);
1222                 }
1223         }
1224         return (NULL);
1225 }
1226
1227 /*
1228  * If delta is applied to dd, how much of that delta would be applied to
1229  * ancestor?  Syncing context only.
1230  */
1231 static int64_t
1232 would_change(dsl_dir_t *dd, int64_t delta, dsl_dir_t *ancestor)
1233 {
1234         if (dd == ancestor)
1235                 return (delta);
1236
1237         mutex_enter(&dd->dd_lock);
1238         delta = parent_delta(dd, dd->dd_phys->dd_used_bytes, delta);
1239         mutex_exit(&dd->dd_lock);
1240         return (would_change(dd->dd_parent, delta, ancestor));
1241 }
1242
1243 struct renamearg {
1244         dsl_dir_t *newparent;
1245         const char *mynewname;
1246 };
1247
1248 static int
1249 dsl_dir_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
1250 {
1251         dsl_dir_t *dd = arg1;
1252         struct renamearg *ra = arg2;
1253         dsl_pool_t *dp = dd->dd_pool;
1254         objset_t *mos = dp->dp_meta_objset;
1255         int err;
1256         uint64_t val;
1257
1258         /*
1259          * There should only be one reference, from dmu_objset_rename().
1260          * Fleeting holds are also possible (eg, from "zfs list" getting
1261          * stats), but any that are present in open context will likely
1262          * be gone by syncing context, so only fail from syncing
1263          * context.
1264          */
1265         if (dmu_tx_is_syncing(tx) && dmu_buf_refcount(dd->dd_dbuf) > 1)
1266                 return (EBUSY);
1267
1268         /* check for existing name */
1269         err = zap_lookup(mos, ra->newparent->dd_phys->dd_child_dir_zapobj,
1270             ra->mynewname, 8, 1, &val);
1271         if (err == 0)
1272                 return (EEXIST);
1273         if (err != ENOENT)
1274                 return (err);
1275
1276         if (ra->newparent != dd->dd_parent) {
1277                 /* is there enough space? */
1278                 uint64_t myspace =
1279                     MAX(dd->dd_phys->dd_used_bytes, dd->dd_phys->dd_reserved);
1280
1281                 /* no rename into our descendant */
1282                 if (closest_common_ancestor(dd, ra->newparent) == dd)
1283                         return (EINVAL);
1284
1285                 if ((err = dsl_dir_transfer_possible(dd->dd_parent,
1286                     ra->newparent, myspace)))
1287                         return (err);
1288         }
1289
1290         return (0);
1291 }
1292
1293 static void
1294 dsl_dir_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1295 {
1296         dsl_dir_t *dd = arg1;
1297         struct renamearg *ra = arg2;
1298         dsl_pool_t *dp = dd->dd_pool;
1299         objset_t *mos = dp->dp_meta_objset;
1300         int err;
1301
1302         ASSERT(dmu_buf_refcount(dd->dd_dbuf) <= 2);
1303
1304         if (ra->newparent != dd->dd_parent) {
1305                 dsl_dir_diduse_space(dd->dd_parent, DD_USED_CHILD,
1306                     -dd->dd_phys->dd_used_bytes,
1307                     -dd->dd_phys->dd_compressed_bytes,
1308                     -dd->dd_phys->dd_uncompressed_bytes, tx);
1309                 dsl_dir_diduse_space(ra->newparent, DD_USED_CHILD,
1310                     dd->dd_phys->dd_used_bytes,
1311                     dd->dd_phys->dd_compressed_bytes,
1312                     dd->dd_phys->dd_uncompressed_bytes, tx);
1313
1314                 if (dd->dd_phys->dd_reserved > dd->dd_phys->dd_used_bytes) {
1315                         uint64_t unused_rsrv = dd->dd_phys->dd_reserved -
1316                             dd->dd_phys->dd_used_bytes;
1317
1318                         dsl_dir_diduse_space(dd->dd_parent, DD_USED_CHILD_RSRV,
1319                             -unused_rsrv, 0, 0, tx);
1320                         dsl_dir_diduse_space(ra->newparent, DD_USED_CHILD_RSRV,
1321                             unused_rsrv, 0, 0, tx);
1322                 }
1323         }
1324
1325         dmu_buf_will_dirty(dd->dd_dbuf, tx);
1326
1327         /* remove from old parent zapobj */
1328         err = zap_remove(mos, dd->dd_parent->dd_phys->dd_child_dir_zapobj,
1329             dd->dd_myname, tx);
1330         ASSERT3U(err, ==, 0);
1331
1332         (void) strcpy(dd->dd_myname, ra->mynewname);
1333         dsl_dir_close(dd->dd_parent, dd);
1334         dd->dd_phys->dd_parent_obj = ra->newparent->dd_object;
1335         VERIFY(0 == dsl_dir_open_obj(dd->dd_pool,
1336             ra->newparent->dd_object, NULL, dd, &dd->dd_parent));
1337
1338         /* add to new parent zapobj */
1339         err = zap_add(mos, ra->newparent->dd_phys->dd_child_dir_zapobj,
1340             dd->dd_myname, 8, 1, &dd->dd_object, tx);
1341         ASSERT3U(err, ==, 0);
1342
1343         spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa,
1344             tx, "dataset = %llu", dd->dd_phys->dd_head_dataset_obj);
1345 }
1346
1347 int
1348 dsl_dir_rename(dsl_dir_t *dd, const char *newname)
1349 {
1350         struct renamearg ra;
1351         int err;
1352
1353         /* new parent should exist */
1354         err = dsl_dir_open(newname, FTAG, &ra.newparent, &ra.mynewname);
1355         if (err)
1356                 return (err);
1357
1358         /* can't rename to different pool */
1359         if (dd->dd_pool != ra.newparent->dd_pool) {
1360                 err = ENXIO;
1361                 goto out;
1362         }
1363
1364         /* new name should not already exist */
1365         if (ra.mynewname == NULL) {
1366                 err = EEXIST;
1367                 goto out;
1368         }
1369
1370         err = dsl_sync_task_do(dd->dd_pool,
1371             dsl_dir_rename_check, dsl_dir_rename_sync, dd, &ra, 3);
1372
1373 out:
1374         dsl_dir_close(ra.newparent, FTAG);
1375         return (err);
1376 }
1377
1378 int
1379 dsl_dir_transfer_possible(dsl_dir_t *sdd, dsl_dir_t *tdd, uint64_t space)
1380 {
1381         dsl_dir_t *ancestor;
1382         int64_t adelta;
1383         uint64_t avail;
1384
1385         ancestor = closest_common_ancestor(sdd, tdd);
1386         adelta = would_change(sdd, -space, ancestor);
1387         avail = dsl_dir_space_available(tdd, ancestor, adelta, FALSE);
1388         if (avail < space)
1389                 return (ENOSPC);
1390
1391         return (0);
1392 }
1393
1394 timestruc_t
1395 dsl_dir_snap_cmtime(dsl_dir_t *dd)
1396 {
1397         timestruc_t t;
1398
1399         mutex_enter(&dd->dd_lock);
1400         t = dd->dd_snap_cmtime;
1401         mutex_exit(&dd->dd_lock);
1402
1403         return (t);
1404 }
1405
1406 void
1407 dsl_dir_snap_cmtime_update(dsl_dir_t *dd)
1408 {
1409         timestruc_t t;
1410
1411         gethrestime(&t);
1412         mutex_enter(&dd->dd_lock);
1413         dd->dd_snap_cmtime = t;
1414         mutex_exit(&dd->dd_lock);
1415 }
1416
1417 #if defined(_KERNEL) && defined(HAVE_SPL)
1418 EXPORT_SYMBOL(dsl_dir_set_quota);
1419 EXPORT_SYMBOL(dsl_dir_set_reservation);
1420 EXPORT_SYMBOL(dsl_dir_open);
1421 EXPORT_SYMBOL(dsl_dir_close);
1422 #endif