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